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Application of Freezing and Thawing in Apple (Malus domestica) Juice Extraction
Abstract
en The paper presents the results of the research on the impact of enzymatic liquefaction, freezing and thawing on the efficiency of juice pressure extraction from apple pulp and quality of the obtained juices. The research was conducted using three types of pretreatment prior the pressing: crushing and enzymatic liquefaction in temperature of 25 °C, crushing and enzymatic liquefaction in temperature of 45 °C and crushing followed by freezing and thawing of the pulp. The study included three varieties of apples. The juice was obtained using a laboratory basket press. It was determined that the pretreatment of the pulp as well as the varietal characteristics of the fruits have a significant impact on the efficiency of the pressure extraction process. The enzymatic treatment of the pulp, irrespective of the temperature at which it was conducted, significantly increased the efficiency of the process. No effect of the temperature (25 or 45 °C) of enzymatic treatment on the efficiency of the pressure extraction process was found. Pretreatment of the pulp based on freezing and thawing contributes to the increase of efficiency of pressing in the case of two apple cultivars, that is, Idared and Red Delicious. It was showed that total phenolic content, antioxidant activity, the soluble solids content and juice acidity (pH) depend on the pretreatment of the pulp and the varietal characteristics of apples. Following the application of pretreatment of the pulp, an increase was observed in the content of polyphenols and in the antioxidant activity of the juices obtained.
Practical Application
pt Freezing and thawing as a pretreatment allows to eliminate enzymatic liquefaction of mash before press extraction. The suggested new method of the use of freezing and thawing techniques enables development of the production of juice with a very good sensory and prohealth properties.
... Similar results were also reported by much previous research. The pH values were determined to range from 3.34 to 3.68 [36] and from 3.39 to 3.77 [18]. The pH value of juices is influenced by the variety, date of apple harvest, the method of obtaining and further processing of juices. ...
... The pH values were determined to range from 3.34 to 3.68 [36] and from 3.39 to 3.77 [18]. The pH value of juices is influenced by the variety, date of apple harvest, the method of obtaining and further processing of juices. ...
... The big differences in the concentration of polyphenols can be attributed to raw material variety, cultivation conditions, climate, as well as the methods of juice extraction and processing [18]. The total phenolic content in juices produced in Europe varies within a broad range, from 10 to 500 mg GAE·100 −1 ·mL −1 [9,38,39]. ...
The paper presents the comparison of quality of six different commercial apple juices produced in Poland. The apple juices came from two different Polish companies. From each manufacturer three various juices were selected: two cloudy and clarified one produced as a mixture of different apple varieties. The following properties were evaluated: density, soluble solid content, viscosity, total phenolic contents, phenolic acid, and antiradical activity. The obtained results showed that three from fourth cloudy juices (M1Sz, M1A and M2A) differed from clarified juices. The highest differences were noticed for total phenolic contents, phenolic acids, antiradical activity and viscosity. The values of these properties ranged between 60.72–103.6 mg GAE·100−1 mL−1 for phenolic contents, 78.3–90.9% for antiradical activity and 2.68–5.79 mPa·s for viscosity. The remaining cloudy juice (M2Sz) was more similar to the clarified ones. The strong correlation between total phenolic content and antiradical activity of apple juices was found. The high correlation coefficient obtained between these features indicates that both producers do not apply excessive amounts of vitamin C during the production of cloudy apple juices. There was also a strong interrelation between the density of juice and solid soluble content. However, no correlation was found between the solid soluble content and the viscosity of the tested juices.
... Applying physical methods of pulp treatment may reduce the negative alterations in the raw material and, as a result, in juice [19]. For physical pulp pretreatment, the following methods are used: ohmic heating [20], pulsed electric field [21,22], electro-osmosis [23], radiation [24], microwave heating [25,26], sonication [27], as well as freezing and thawing of the pulp [13,28,29]. Freezing is used to preserve foods. ...
... With reference to many studies, the freezing process negatively affects the pro-health properties of food only to a small extent, and for that reason, this method is commonly used in the food processing industry [32,33]. Nadulski et al.'s [13,28,29,34] study proves the possibility of maintaining the pro-health properties of fruit and vegetable juices while applying freezing and thawing methods as pulp pretreatment. To the best of our knowledge, there is no evidence regarding the use of freezing and thawing as a method supporting the process of pressing juice from celeriac roots. ...
... Sharma [38,39] et al. point out that the pressing yield of root vegetables depends primarily on the degree of material grinding, its temperature, and enzymatic treatment. According to Nadulski et al. [13,28,29], the process of freezing and thawing as a pretreatment method before pressing affects the intensification of obtaining juice from vegetables and fruits, such as carrots, rhubarbs, and apples. Piłat and Zadernowski [40] and Trappey et al. [41] also observed an increase in the pressing efficiency in the case of thawed fruit. ...
The aim of this study is to indicate the influence of pretreatment, consisting of grinding vegetables and then freezing and thawing the raw material before pressing on the process efficiency and quality of obtained juice. The subject of the research was celeriac root (Apium graveolens L) of the Edward variety. Juice pressing was carried out in a laboratory basket press. The pressing yield and specific energy were values characterizing the pressing process, while pH and the extracted content in the juice were used to assess the juice quality. The experiment was performed according to three procedures. In each of them, the ground celeriac root (pulp or chips) was initially pretreated through freezing and thawing and then pressed twice. Among the examined methods of obtaining juice, the most beneficial method was pressing juice from the pulp, then freezing and thawing the pomace obtained in the first cycle, and finally, pressing the pomace. It is an energy-optimal method and guarantees a high pressing yield as well as obtaining juice with a higher soluble solid content than during the process of pressing chips.
... The main aim of apple processing is the production of juice and its concentrate. The process of juice production can be supported by the use of various forms of pretreatment [10]. The waste produced after pressing apple juice is called pomace. ...
... The pressing process was carried out on the pulp and was not subjected to enzymatic treatment. Juice extraction was carried out using a laboratory self-constructed basket press with a capacity of approximately 1000 mL [10]. The press allowed for a process efficiency of between 60% and 70%, i.e., within the range typical of small-scale processing plants run by producer groups of farmers. ...
The aim of this study was to develop a concept, within the framework of sustainable agriculture, for utilizing apple pomace as a valuable raw material in food production. The proposal includes a description of the production technology of four food products together with the characteristics of their chemical composition, wholesome compounds, and physical properties. These new products were developed on the basis of apple pomace and wheat bran. In the developed technology, heat treatment in a convection oven, treatment with infrared radiation, and two types of barothermic treatments, i.e., extrusion and granulation, were implemented as the principal methods. All of the proposed technologies allow for the use of pomace for the production of food products to be made directly in the home plant and are relatively easy to implement in small processing facilities. It was found that the product consisting of fragmented apple pomace (mass fraction: 75%) and wheat bran (mass fraction: 25%), obtained using infrared radiation treatment, had the greatest value in terms of wholesome characteristics among the products obtained. This product had high contents of fiber and simple sugars, the highest content of polyphenols among the obtained products, and the ability to scavenge free radicals. It was also the only one with partially preserved vitamin C. The proposed method for processing pomace for food is in line with the sustainable agriculture movement.
... Juices produced in Europe are characterized by a high polyphenol content variability, from 10 to 300 mg GAE•100 mL −1 [28]. In turn, the content of polyphenols in apples ranges from 11.88 to 585.52 mg GAE/100 g of wet weight [29]. ...
... On the other hand, Vrhovsek et al. [30] reported that the contents of total polyphenols in apples are between 66.2 and 211.9 mg/100 g of fresh weight, depending on the variety. Juices produced in Europe are characterized by a high polyphenol content variability, from 10 to 300 mg GAE·100 mL −1 [28]. In turn, the content of polyphenols in apples ranges from 11.88 to 585.52 mg GAE/100 g of wet weight [29]. ...
The paper presents the possibility of applying a twin-screw press for juice extraction from apples with different textural properties. The research was carried out with six different varieties; namely, Granny Smith, Modi, Ligol, Lobo, Boscop and Szampion. During the experiment, the following properties were measured: texture properties, pressing yield and polyphenolic content; and ascorbic acid content and antioxidant activity both in raw apples and apple juice. Based on the analysis, three hardness levels of apples can be distinguished, impacting the course of juice pressing in a twin-screw press (low hardness below 30 N, medium hardness 30–50 N and high hardness 50 N). The study showed that only high hardness apples are suitable for pressing on a twin-screw press. The mechanism by which texture properties influence the juice pressing process in the studied press was explained. It was further demonstrated that the hardness of apples has a positive impact on the degree of extraction of polyphenols and ascorbic acid into apple juice. This is caused by the different fracture patterns of tissues with different mechanical properties. High hardness apples (Granny Smith and Modi) were characterized by a considerably greater degree of bioactive substance extraction into juice than medium hardness apples.
... As shown by several studies, treatment of this type not only improves the efficiency of extraction but also contributes to an increase in the degree of release of polyphenols and in free-radical quenching activity [12,13,15,16]. In recent years, alternative methods have been investigated to treat fruits and vegetables prior to pressing, for example, by freezing and thawing of pulp [17,18]. Freezing is considered to be an almost noninvasive method of food preservation that does not cause degradation of biologically active components. ...
... Two types of presses were used for juice extraction-a piston press with a basket or the authors' own design [18] and a twin gear juice extractor (Green Star Elite 3000, Tribest). For the basket press, 300 g portions of raw material (whole or shredded fruits) were placed in a bag; the bag was then placed in the working chamber and loaded using the piston. ...
The primary objective of the study was to determine the effect of process conditions on extraction efficiency and the total amount of released polyphenols and antioxidant activity (AA) in black chokeberry juice. The study samples were fruits of black chokeberry (Aronia melanocarpa (Michx.) Elliott) cv. Galicjanka. In the study, two kinds of presses-piston press and twin gear juice extractor-were used, and two raw material pretreatment methods-freezing and thawing and enzymatic liquefaction-were applied. The study showed that pressing efficiency depends on the design of press and the nature of pretreatment. The highest pressing efficiency was obtained using the twin gear juice extractor. Enzymatic liquefaction of shredded fruits significantly increased the efficiency of pressing by the piston press. The type of press and the pretreatment method used had an effect on the quality traits of the extracted juices. The highest content of soluble solids was obtained for fruits not subjected to any pretreatment and pressed using the twin gear press. The highest total phenolic content was obtained in juice extracted using the piston press from shredded fruits subjected to enzymatic treatment at 45°C. A higher total phenolic content was also a characteristic of juice obtained from fruits not subjected to any pretreatment and extracted using the twin gear press. The capacity of the black chokeberry juices for free radical quenching oscillated around the level of approximately 90%. The study showed that the application of suitable processing methods is necessary for the acquisition of products with desirable quality traits.
... Means with different lowercase letter indicate the significant differences (p < 0.05) among the samples and were performed separately for each day of storage. The fresh apple juice had pH values between 3.87 and 3.89, values close to those obtained by Giryn et al. [71], Nadulski et al. [72], and Falguera et al. [73]. On the market, there are apple juices with pH values that vary from 3.0 to 4.5 [74]. ...
Natural preservatives such as garlic and ginger can be added to the formulation of fresh fruit juices to encourage the consumption of health-promoting foods. In this study, the influence of garlic and ginger and the storage conditions on physicochemical and microbiological characteristics of fruit juices were investigated. The fruit juice assortments were produced from apple, apple and pumpkin, and apple and pomegranate and were treated with 0.5 g garlic powder, 0.5 g ginger powder, and 0.25 g mix of garlic and ginger powders. A total of 12 unpasteurized samples were produced, of which 3 were control samples. Samples stored at 20 and 4 °C were analyzed at 0, 3, 6, and 9 days for water activity (aw), pH, titratable acidity (TA), total soluble solids (TSS), electrical conductivity (EC), vitamin C, color parameters, total number of germs, yeasts, and molds, Listeria, Enterobacteriaceae, and Escherichia coli. Results showed that aw, pH, TSS, and vitamin C content decreased during storage of fruit juice samples, while TA increased. The lowest increase in total number of aerobic mesophilic germs was determined for the apple and pumpkin juice with garlic and ginger and apple juice with garlic.
... The blended pulp was kept again in a deep freezer at −20 ± 2°C for further experiments. The thawing of sieved bael fruit pulp was performed as per the procedure of Nadulski et al. (2016) for further experiments. The storing (at −20 ± 2°C) and thawing processes have shown a negligible effect on the color and physiochemical properties of bael fruit and pulp. ...
Bael fruit pulp was treated with pectinase enzyme for the easy extraction and high recovery of juice with nutritive properties. The response surface methodology (RSM) and artificial neural network (ANN) modeling were carried out on runs of Box-Behnken design of three variables for the optimization process and identification of the best modeling method. Pectinase concentration of 0.22 g/100 g of pulp, the temperature of 46.20°C, and time of 6.35 hours was found out to be RSM optimized value of variables whereas pectinase concentration of 0.18 g/100 g of pulp, the temperature of 46.81°C and time of 6.09 hours was obtained to be ANN-GA optimized value of variables. From the values of the coefficient of determination (R 2), root mean squared error (RMSE), and mean absolute error (MAE), ANN was found out to be better than RSM. This research would help in the commercial production of bael fruit juice on an industrial scale.
... Before being pressed in a piston press, the apples were crushed using an MKJ250 shredding machine (Spomasz Nakło, Poland) with a standard grating disk with 8 mm holes. Juice was obtained using three devices: a self-made laboratory piston press [28], a double-screw press (Green Star Elite 3000, Tribest), Appl. Sci. ...
This paper presents the results of a study on the influence of juice extraction and thermosonication methods on the content of microorganisms in juices stored under refrigeration and in ambient temperature. It was determined that the type of extraction device used influenced the content of microorganisms in juice. The lowest total content of mesophilic microorganisms was obtained in juice extracted on a piston press, and the highest was obtained using a centrifuge. The additional purpose was to evaluate the influence of ultrasonic treatment on selected parameters of apple juice quality: cloud value, antioxidant activity, total phenolic content, flavonoid content, and anthocyanin content. The ultrasound treatment of juice from the piston press was conducted at two levels of radiated sonic power so as to obtain sublethal and lethal temperatures of the juice. It was demonstrated that only ultrasound treatment within the range of lethal temperatures was sufficient to deactivate microorganisms. It was determined that thermosonication did not influence the deterioration of chemical properties of juices, with the exception of decreased anthocyanin content. The described method enables prolongation of the shelf life of fresh apple juice under refrigeration to 168 hours (7 days).
... [1][2][3] Apples are an important dietary source of phenolic compounds, including chlorogenic acid, caffeic acid, catechin and epicatechin. [4][5][6] Additionally, apple peels are rich sources of quercetin glycosides, which are absent or present at only trace levels in apple pulp. 7 The phenolic composition in apples depends on the genotype (i.e. ...
Background
New early‐ to mid‐season apple cultivars are being developed to help address warmer growing seasons due to climate change. Free sugars, organic acids, total phenolic content, total flavonoid content, antioxidant activity and phenolic composition were determined in the pulp and peel of six new and six traditional apple cultivars. In addition, the phenolic profiles of apple peels were characterized using high‐resolution mass spectrometry. Forty‐eight polyphenol compounds were identified, by accurate mass, in apple peel.
Results
Compared to Fuji apples, a new apple cultivar, Decobell, contained 2.6‐ and 1.4‐fold higher levels of the sum of individual polyphenol levels in the peel and the pulp, respectively. Decobell apples showed similar sugar‐to‐acid ratio (0.27) to Fuji apples (0.25).
Conclusions
The results indicate that the Decobell cultivar could have the best quality characteristics in terms of sugar‐to‐acid ratios and health‐promoting activities due to the phenolic profiles. © 2019 Society of Chemical Industry
... In this industry, great attention is paid to workers safety and health evaluation like in other agroindustry and agricultural sectors [5][6][7]. The method of pulp processing and the method of juice production as well as the parameters of these processes have a major influence on the efficiency and quality of the juice obtained [8]. The health-promoting value of apples is related among others to the content of polyphenols and soluble fractions of dietary fibre. ...
Abstract. The process of fruit juices production should be characterised by a high efficiency, while the final
product should have a high content of soluble solids, low acidity and a high content of health-promoting
components. Currently, screw presses are becoming increasingly popular especially on small farms and
households. Their construction has a great impact on yield pressing and quality characteristics of juice. The
primary objective of this study was to determine the effect of the press type on juice extraction efficiency and on
the total amount of released polyphenols. The scope of the study included also the determination of the juice
quality parameters such as the content of soluble solids, pH, viscosity and density. Apple fruits were pressed
using two types of machines: a single-screw press and a twin gear juice extractor. Study results demonstrate that
the pressing efficiency depends on the press construction. The highest yield of extraction was obtained for the
twin-screw press. Under the experimental conditions, there was no influence of the press type on the quality
properties of the juice, except for its viscosity. However, the quality characteristics of the juice depended on the
apple variety. Higher contents of the extract and polyphenols were obtained in juice from the apple var. Jonagold
juice and viscosity in juice from the apple var. Ligol juice. The use of the press offers the possibility of
producing juices with desirable quality traits.
... Juice was pressed by means of a laboratory basket-type press of an oiriginal design, with diameter of 120 mm and volume of approx. 150 cm³ (Nadulski, Kobus, Wilczyński, Zawiślak, Grochowicz, Guz, 2016). Each measurement was made in six replicates. ...
... Previous studies conducted by Kocira, A. et al. (2015, and Kocira et al. (2016) also demonstrated that the use of Nano-Gro, Kelpak (Ecklonia maxima extract), and Atonik biostimulants increased both the content of polyphenolic compounds and the antioxidative potential of common bean. Our experiments and other studies have shown that both contents of bioactive compounds and antioxidative potential depend on the types of biostimulants used, their concentrations and the number of applications and the subsequent treatment of the raw material (Kocira, A. et al., 2015Oniszczuk et al., 2015;Bouasla et al., 2016;Kocira et al., 2016;Nadulski et al., 2016). ...
In recent years, attempts have been made to use preparations that allow obtaining high and good quality yields, while reducing the application of pesticides and mineral fertilizers. These include biostimulants that are safe for the natural environment and contribute to the improvement of yield size and quality, especially after the occurrence of stressors. Their use is advisable in the case of crops sensitive to such biotic stress factors like low temperatures or drought. One of these is soybean which is a very important plant from the economic viewpoint. Field experiments were established in the years 2014-2016 in a random block design in four replicates on experimental plots of 10 m². Three soybean cultivars: Annushka, Mavka, and Atlanta were planted in the third decade of April. Fylloton biostimulant was used at 0.7% or 1% concentrations as single spraying (BBCH 13-15) or double spraying (BBCH 13-15, BBCH 61) in the vegetation period. The number of seeds per 1 m², seed yield, thousand seed weight, number of pods per plant, number of nodes in the main shoot, height of plants, and protein and fat contents in seeds were determined. The content of phenolic compounds, antioxidant capacity and antioxidant effect of soybean seeds were assayed as well. Foliar treatment of soybean with Fylloton stimulated the growth and yield of plants without compromising their nutritional and nutraceutical properties. The double application of the higher concentration of Fylloton was favorable for the plant height, seed number and soybean yield. Moreover, the highest number of pods was obtained after single treatment of plants with the lower biostimulant concentration. There was also a positive effect of using this biostimulant on the content and activity of some bioactive compounds, such as phenolics and flavonoids, and on the reducing power.
The aim of this study was to analyse changes on the new farm tractors market in Poland. The work covered the period between 2010 and 2020, and was based on new farm-tractor sales data measured by the number of registrations. The paper presents the semi-annual sales figures, the demand for selected tractor brands, and the sales of new farm tractors representing various engine power segments. New tractors were considered to be those registered for the first time in Poland with either the same or preceding year of manufacture. Between 2010 and 2020, over 144,000 new farm tractors were registered in Poland, with the highest number of tractors sold being recorded in 2012, and the lowest in 2016. Unfortunately, no Polish brand made its way to the top 10 of the top-selling tractors. The Polish market was largely dominated by tractors produced in Western Europe and the USA. The analysis revealed that New Holland tractors (23,780 vehicles) accounted for the largest number of registrations, followed by John Deere (19,453), Zetor (16,398) and Deutz-Fahr (10,508). The total share of these four manufacturers between 2010 and 2020 was 48.6%. In the reference period, vehicles representing the 51–70 kW engine power segment had the largest share (35.17%), followed by 71–100 (24.44%), 31–50 (14.00%), <30 (7.68%), 101–120 (7.4%), 121–140 (4.85%), >161 (3.69%), and 141–160 kW (2.76%). Among the farm tractors representing lower power segments, i.e., up to 50 kW, Kubota was the most frequently purchased brand. As regards higher engine power segments, i.e., 50–140 kW, New Holland tractors held market dominance, while in the >140 kW engine power segment, John Deere tractors were prevalent.KeywordsFarm tractorTractors marketSales of farm tractors in PolandRegistrationEngine power
The objective of this research was to investigate the effect of using different design of agricultural nozzles on the spray effectiveness in the wheat plants canopy. Moreover, the effect of using worn nozzles on the spray quality was also evaluated. Four types nozzles was used in the tests: TT, TTj60, DG, and XR. They are produced by TeeJet (Spraying Systems Co., Illinois USA). The first three types has a pre-orifice design, while XR was considered as control treatment because it is wide used internationally. Nozzles were subjected to the accelerated wear test according to the ASAE S471 standard. The flow rate after finishing the accelerated wear test was reached to 10% higher than the nominal flow rate, and these nozzles was named “Worn nozzles”. These nozzles (new and worn) was evaluated concerning its spray quality in wheat plants in the laboratory conditions, and using water sensitive papers (WSP). Spray coverage (%), stains diameter (μm), and stains density on square centimetre were calculated. Results data showed that highest spray coverage was achieved using the XR worn nozzles (19%), while using TTj60 nozzle (new and worn) resulted in the lowest value of coverage (14% for both). Biggest stain diameter was registered when using worn DG nozzle (538 μm), lowest value of stain diameter was 445 μm when using new XR nozzle. Concerning the spray density, XR nozzle (new and worn) produced highest spray density, while using worn TT nozzle resulted in the lowest number of stains on square centimetre (333 stain/cm2).
The aim of the study was to determine the chemical composition of pomace from various apple varieties in terms of their suitability for the production of food products. The research covered pomace obtained from five apple varieties. The content of dry matter, ash, protein, fat, sugar, sorbitol, vitamin C, dietary fiber, polyphenols and antioxidant activity were determined. Significant differences in the chemical composition of the tested pomace were found, especially in terms of the content of health-promoting compounds. Therefore, when processing the pomace for food purposes, it is important to take into account the variety of apples they come from. Due to its chemical composition, pomace from the Szempion variety is particularly suitable for food purposes.
Worldwide, one of the most consumed fruit juices is apple juice, preferred by both adults and children due to its authentic taste, but also due to its nutritional and health benefits. Apple juice contains sugars, malic acid, soluble pectin, vitamin C, phytochemicals and minerals. The production process influences the juice composition. There is a growing market for natural cloudy apple juice, even though fruit juice is mostly consumed as clear juice. The aim of this study was to obtain cloudy apple juice by using a blender and a cold pressing juicer for extraction and to evaluate their physico-chemical and sensory qualities. The apple juice samples were obtained from three different apple cultivars: “Gala”, “Braeburn” and “Golden Delicious”. After extraction, apple juice samples were pasteurized and cooled. In this study, physico-chemical analyzes (like moisture, water activity, pH, titratable acidity, total soluble solids, electrical conductivity, color parameters) were performed immediately after processing and at 7, 14, 21 days of storage at room temperature. The results showed that the investigated parameters of the apple juice samples varied differently depending on both the apple cultivar and the processing method used. Sensory analysis showed that certain types of apples can be suitable for extracting juice using a blender (“Golden Delicious”), while others such as “Gala” apples can be used to obtain juice by cold pressing.
The aim of this research was to investigate the drop size distribution of the standard flat fan nozzle in different positions of its spray fan. Moreover, the symmetry of the drop size distribution of the spray fan was checked by comparing the right and left side of the spray fan. Drop size distribution was measured by laser diffraction device (Sympatec GmbH-HELOS-VARIO/KR). There were fifteen measurement positions alongside the spray fan, seven position on the right side and the same number on the left beside one measurement on the spray fan centreline. The measurements were done with 3.0 bar pressure and in 50cm bellow the nozzle tip. The results showed that almost two-third of the spray volume is consisted of drops sizes ranging from 100 to 300 mu m. The two sides of the spray pattern were identical at the middle positions (near the centreline) for all drop size ranges. However, there was a slight difference between right and left side of the spray pattern concerning the drop size ranges at the edge positions.
This study investigates the effects of pulsed electric fields (PEF) and freeze thawing (FT) pretreatments on juice yield and quality from chicory by pressing (P). The four different modes (P, PEFP, FT-P and P-PEF-P) were compared. The effects of pressing mode, PEF conditions, cossettes size on the juice yield, and total soluble matter (°Bx), conductivity, pH, turbidity in expressed juices were evaluated. The pressing kinetics for different modes were also investigated. For studied modes, the highest juice yield and kinetic rate were obtained for FT-P mode, the lowest was P mode. PEF-P and P-PEF-P modes resulted in the same juice yield, an increase of 9% higher than P mode. A 600 V/cm of intensity and 0.2 s duration were optimal PEF conditions with desired energy consumption. Moreover, cake mixing and relative small-sized cossettes allowed improving juice yield assisted by PEF-P mode. Quality analysis showed that expressed juice from smaller cossettes by PEF-P mode has lower turbidity and higher inulin content.
To optimally design post-harvest handling and processing equipment for unripe green grape berries, it is necessary to determine the physical and mechanical properties of the product. In the current study, dimensional (by image processing), gravimetrical, frictional, and aerodynamic (by image processing) properties of unripe green grape berries affected by storage time (31 days in refrigerator) were investigated. Besides, rupture force, rupture energy, elasticity modulus, toughness, hardness, maximum compressive contact stress, Poisson's ratio (by image processing), and shear modulus in horizontal and vertical loading under different moisture content and loading rate levels were measured. Moreover, to model loading and stress-relaxation behavior of bulk berries, berries were poured into cylinder and compressed. Effects of cylinder diameter, loading rate, the height of layers, and number of layers on loading and stress-relaxation behavior were investigated. During storage, as the moisture content decreased from 94.57 to 83.88% (w.b.), dimensions and mass of the berries decreased while bulk density and true density increased. With decreasing the moisture, friction angles on galvanized, iron, and rubber were ranged from 22.43° to 26.73°, from 25.38° to 28.53°, and from 29.7° to 34.2°, respectively. Filling angle of repose ranged from 13.44° to 17.65° and emptying angle of repose ranged from 13.95° to 18.33°. In the mentioned moisture range, terminal velocity increased from 0.202 to 0.275 m s⁻¹, and drag coefficient increased from 0.180 to 0.272. Reducing moisture content and increasing rupture energy of the fruits during storage indicates that berries' juice should be extracted immediately after harvest.
Practical Applications
Unripe grape berries with a sour taste can be processed into several sour sauce and verjuice products. Therefore, determining the physical properties of unripe grape berries is essential for the design of harvesting and post-harvesting equipment. The current work aims to determine unripe grape berries' physical and mechanical properties to recognize their relevance in physico-mechanical processing. Some of the necessary information for designing and manufacturing harvesting and post-harvesting machines is provided in this research. Thus, the results provided in the present study would contribute to improving juice extractors, sorters, separators, cleaners, storage structures, dryers, aeration equipment, conveyors, pneumatic elevators, and so forth, designed for the unripe grape berries.
This study was conducted to examine the effect of freezing in the tea preparation using Camellia sinensis leaves in order to develop new technology for improving tea quality. Effects of single and combined treatments of freezing (F: - 20 °C, 15 days), steaming (S: 100 °C, 3 min), and hot-air drying (HD: 50 °C, 12 h) on the physicochemical characteristics of tea (powder and hot-water leachate) prepared from treated Camellia sinensis leaves were investigated. The L
*
, b
*
, and C
*
values of the powder were the highest in SHD-treated leaves, followed by HD-, SFHD-, and FHD-treated leaves. Redness (+a* value) was only seen in FHD-treated leaves and greenness (- a* value) was the highest in SHD-treated leaves. Browning index of the leachate was significantly lower in SHD- and SFHD-treated leaves than in FHD-treated leaves (p < 0.05). Soluble solids, acidity, and phenolic compounds of FHD-treated leaves were significantly lower than in SHD- and SFHD-treated leaves (p < 0.05). Sucrose was highest in SHD-treated leaves and glucose was highest in FHD-treated leaves. Sensory preference was better evaluated in FHD-treated leaves than in SHD- and SFHD-treated leaves. These results suggest that freezing treatment in tea processing promotes browning and component decomposition and enhances sensual preference. Therefore, freezing has a potential application in the tea manufacturing.
In this study, we assessed the effect of freezing pretreatment on the quality of osmotically extracted syrup from Citrus junos peels. Sliced peels were frozen for 7 days at −20°C or −70°C, mixed with sucrose and then stored for 40 days at 15°C. Syrups were prepared from these mixtures after osmotic treatment. Non-frozen fruits were used as control. The initial freezing point of C. junos peels was −4°C. Nominal freezing times were 42 and 13 min for −20°C and −70°C, respectively. The osmotically extracted syrup from the frozen peels was reddish brown while that of the untreated peels was yellow. The titratable acidity of the pretreated syrups was significantly higher than that of the untreated syrup, but clarity, vitamin C content, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity were considerably lower. The pretreated syrups showed no notable difference in color, titratable acidity, clarity, and DPPH activity. Furthermore, contents of soluble solids, phenolic compounds, and flavonoids were unaffected. These results suggest that freezing before osmotic extraction affects the quality, producing syrups with higher acidity, reddish brown color, and lower antioxidant activity.
The paper presents the possibility of applying different press constructions for juice extraction in small farms. The research was carried out with three different varieties of apples, namely, Rubin, Mutsu, and Jonaprince. Two types of presses were tested: a basket press and a screw press. Generally, application of the screw press makes it possible to obtain a higher yield of extraction compared to the basket press. In our study, the differences in the pressing yield among press machines also depended on the apple variety used. The juices obtained on the screw press were found to be of a higher quality characterized by a higher content of soluble solids, higher viscosity, higher total content of polyphenols, higher antioxidant activity, and lower acidity. Thus, the selection of an appropriate press is the key to producing high-quality apple juice with health-promoting properties for manufacturers of apple juice at the local marketplace.
The effect of ascorbic acid and N2 usage in large-scale cloudy apple juice production was investigated. Samples were stored at 5 and 20C for 6 months. The quality of the initial cloudy apple juice samples was evaluated by characteristic properties (pH, total titratable acidity, total dry matter, soluble solids and total phenolic content) and storage stability was evaluated by turbidity and color parameters, which were analyzed on a monthly basis. According to the results, change in total phenolic content of the samples was considerable (minimal values were recorded in N2-treated groups). However, ascorbic acid and N2 usage alone or in combination was not enough to prevent turbidity loss during storage. Only the lower temperature (5C) chosen was effective to decelerate this loss. In terms of color stability, the most stable group was the N2 and ascorbic acid-treated one (ΔE: 3.59 at 5C).
Color and cloud stability are important attributes of cloudy apple juice during storage. Many laboratory studies have been conducted to improve these quality parameters. However, there is no large-scale study about the storage stability of cloudy apple treated by N2 and ascorbic acid during the production stages. Therefore, in this study, a large-scale cloudy apple juice production was performed using N2 and ascorbic acid during the juice processing stage and the storage stability of the final products was investigated for 6 months. The results of this large-scale study could be useful for fruit juice processors and retailers.
O conceito da tecnologia limpa visa otimizar o processo de extração para obter o máximo de suco da fruta, diminuir perdas e gerenciar a aplicação do resíduo gerado. A utilização de complexos enzimáticos, constituídos por celulases e pectinases, na extração de suco permite, além de modificar características químicas e físico-químicas dos produtos, minimizar a geração de resíduos. O objetivo deste trabalho foi avaliar as condições de extração de suco de maçã por liquefação enzimática e comparar as características de qualidade dos produtos obtidos a partir desse método com os do tradicional processo de prensagem. Para o processo de liquefação, as melhores condições para obtenção de suco de maçã foram: enzimas 0,1 mL.Kg-1, temperatura 50 °C e tempo 75 min. O rendimento foi de 83,5% com a geração de 16,5% de bagaço, com uma diferença de 19%, quando comparado ao processamento de suco por prensagem. O suco obtido por liquefação foi mais ácido, apresentou maiores teores de cinzas e de nitrogênio do que o suco obtido por prensagem. No bagaço obtido por liquefação, os valores de acidez e cinzas, de extrato etéreo e de nitrogênio foram maiores do que no obtido por prensagem mas não houve diferença significativa nos teores de fibras alimentares embora os teores de pectina tenham sido mais baixos. Não foram detectadas diferenças significativas nas proporções de açúcares neutros relacionados à parede celular. O processamento por liquefação apresentou melhores resultados no rendimento do suco e na diminuição de bagaço, com uma vantagem de 18,5% sobre o processamento tradicional por prensagem.
Although conventional thermal processing is still the most commonly used preservation technique in cloudy apple juice production, detailed knowledge on phenolic compound degradation during thermal treatment is still limited. To evaluate the extent of thermal degradation as a function of time and temperature, apple juice samples were isothermally treated during 7200 s over a temperature range of 80–145 °C. An untargeted metabolomics approach based on liquid chromatography–high resolution mass spectrometry was developed and applied with the aim to find out the most heat labile phenolic constituents in cloudy apple juice. By the use of a high resolution mass spectrometer, the high degree of in-source fragmentation, the quality of deconvolution and the employed custom-made database, it was possible to achieve a high degree of structural elucidation for the thermolabile phenolic constituents. Procyanidin subclass representatives were discovered as the most heat labile phenolic compounds of cloudy apple juice.
The clean technology concept aims to optimize juice extraction in order to obtain high yields, low losses and to manage the use of residues. The preparation of enzymes available nowadays containing depolimerizing activities like pectinases and celulases reach high yields of modified apple juice with less by-products. The main objective of this work was to establish the conditions for apple juice processing by enzymatic liquefaction and to evaluate the apple juice and residual pomace comparing them with that obtained by the traditional pressing extraction. The best conditions found include enzyme concentration of 0.1 mL.Kg-1 and 75 min of reaction at 50 °C. The yield of juice was 83.5% with around 16.5% of residual pomace, which represents 19% more when compared with the results found with traditional pressing processing. When obtained by enzyme liquefaction the juice was more acidic, with higher contents of minerals and of nitrogen than the pressed juice. In the apple pomace left by enzyme liquefaction, the values of acidity and ash of lipids and nitrogen compound were higher than in the pressed pomace but there are significant differences in food fibers although the pectin levels were significantly higher. No differences were found in the proportions of neutral sugars related to cellular walls. Enzyme liquefaction processing shows better results in the juice yield and residual pomace with an advantage of 18.5% over the pressing extraction.
Long-term data on the biochemical composition and yield of juice from apply varieties bred at the All-Russian Fruit Crops
Breeding Research Institute are given. The most promising apple varieties immune and highly resistant to scab are singled
out for producing high-quality juice.
Keywordsapple-variety-juice-biochemical composition-scab immunity
There has been an increasing appreciation and understanding of the link between dietary fruit and vegetable intake and improved health in humans. The widespread and growing intake of apples and apple juice/products and their rich phytochemical profile suggest their important potential to affect the health of the populations consuming them. This review summarizes current clinical, in vitro, and in vivo data and builds upon earlier published reports that apple may reduce the risk of chronic disease by various mechanisms, including antioxidant, antiproliferative, and cell signaling effects. Exposure to apples and apple products has been associated with beneficial effects on risk, markers, and etiology of cancer, cardiovascular disease, asthma, and Alzheimer's disease. Recent work suggests that these products may also be associated with improved outcomes related to cognitive decline of normal aging, diabetes, weight management, bone health, pulmonary function, and gastrointestinal protection.
This paper shows that it is possible to improve antioxidant activity of apple juice by extraction of polyphenolic compounds from apple pomace, as waste, and their addition to the apple juice. Raw apple juice was prepared by pressing of apple mash. After thermal treatment of raw apple juice, depectinisation, additional clarification and filtration, the clarified juice was obtained. In raw and clarified apple juice soluble solids, acidity, reducing sugar, total sugars and brown component content were determined, as well as total dry matter, ash, acidity, reducing sugar, total sugars, total pectins, cellulose and starch content in apple mash and pomace. The total cotent of phenolics in clarified apple juice and apple pomace extract, determined spectrophotometrically using the Folin- Ciocalteu reagent, was 0.496 mg/ml and 6.505 mg/g, respectively. The antioxidant activity of clarified and polyphenol-enriched clarified juice (with addition of apple pomace extract in the concentrations 0.05 g, 0.1 g, 0.5 g and 1 g of phenolic compounds per liter of clarified apple juice) was examined on stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. Based on the obtained results it can be concluded that polyphenol-enriched clarified juice was more effective on DPPH radicals than the clarified apple juice.
There has been increasing interest in the research of flavonoids from dietary sources, due to growing evidence of the versatile health benefits of flavonoids through epidemiological studies. As occurrence of flavonoids is directly associated with human daily dietary intake of antioxidants, it is important to evaluate flavonoid sources in food. Fruits and vegetables are the main dietary sources of flavonoids for humans, along with tea and wine. However, there is still difficulty in accurately measuring the daily intake of flavonoids because of the complexity of existence of flavonoids from various food sources, the diversity of dietary culture, and the occurrence of a large amount of flavonoids itself in nature. Nevertheless, research on the health aspects of flavonoids for humans is expanding rapidly. Many flavonoids are shown to have antioxidative activity, free-radical scavenging capacity, coronary heart disease prevention, and anticancer activity, while some flavonoids exhibit potential for anti–human immunodeficiency virus functions. As such research progresses, further achievements will undoubtedly lead to a new era of flavonoids in either foods or pharmaceutical supplements. Accordingly, an appropriate model for a precise assessment of intake of flavonoids needs to be developed.
Most recent research has focused on the health aspects of flavonoids from food sources for humans. This paper reviews the current advances in flavonoids in food, with emphasis on health aspects on the basis of the published literature, which may provide some guidance for researchers in further investigations and for industries in developing practical health agents.
Frozen foods make up one of the biggest sectors in the food industry. Their popularity with consumers is due primarily to the variety they offer and their ability to retain a high standard of quality. Thorough and authoritative, the Handbook of Frozen Food Processing and Packaging provides the latest information on the art and science of correctly handling and containing frozen foods. The book is divided into five parts for ease of accessibility and comprehension. Fundamentals of Freezing explains the basics of freezing. Facilities for the Cold Chain focuses on freezing-related equipment and facilities. Quality and Safety of Frozen Foods stresses the importance of quality, safety, and the nutritional values of frozen foods. Monitoring and Measuring Techniques for Quality and Safety describes the methods and techniques used to measure and maintain the quality and safety of frozen foods. The final part, Packaging of Frozen Foods discusses topics such as the various packaging materials used, a description of packaging machinery, and the future developments foreseen in frozen food packaging. Providing chapters written by authors with esteemed academic and professional credentials, the Handbook of Frozen Food Processing and Packaging is an essential resource for scientists in the frozen food industry.
This book presents a comprehensive, integrated view of quality in frozen foods. It addresses quality from a number of perspectives: technological (mechanical and cryogenic methods of freezing); categorical (classification of quality loss); analytical (measurement of quality); theoretical (model building); applied (preventative treatments), and administrative (policy). The book focuses on the principles of freezing and the concepts of quality, and is therefore applicable to research and development of all types of products.
Features include: technological and fundamental features of freezing; types of deterioration that occur in frozen foods; treatment to minimize quality losses during freezing and storage; methods to assess quality losses; strategies that impact a frozen product's quality and ultimate consumer acceptance.
The impact of apple pretreatment by pulsed electric field (PEF) on juice extraction using the freezing-assisted pressing was studied. Apple discs were PEF pretreated at electric field strength of E = 800 V/cm and then air blast frozen inside the freezer (-40 ºC). Then, pressing experiments in a laboratory-pressing chamber (2-5 bars) were started at sub-zero temperature (-5 °C). Time evolution of juice yield and its nutritional qualities were compared for PEF and untreated apple samples. High improvements of juice yield were obtained for freeze-thawed (FT) and PEF+FT samples. The combination of PEF + pressing (5 bar) at sub-zero temperature gave optimum results for juice extraction with high levels of carbohydrates, and antioxidant bioactive compounds. At fixed value of extraction yield, Y, PEF pretreatment improved nutritional parameters. E.g., at Y=0.6, an increase in °Brix (by ≈1.27), carbohydrates (by ≈1.42), total phenolic compounds (by≈1.16), flavonoids (by ≈1.09) and antioxidant capacity (by ≈1.29) was observed after PEF pretreatment.
This study reports the influence of freezing and thawing techniques, as a pre-treatment, on the efficiency and quality of rhubarb (Rheum rhaponticum L., Lider and Malinowy varieties) juice yielded by pressing. Pre-treatment of rhubarb fragments by freezing and thawing caused a significant increase (up to 30%) in the efficiency of the pressing process. Juices obtained with this method showed higher extract content and slightly higher acidity, but had similar dynamic viscosity. All the juices obtained showed the features of Newtonian fluid. Interestingly, the juices obtained with various technologies had significantly different chemical composition. Higher level of oxalates was recorded when preliminary freezing and thawing treatment was used. Both double pressing and the pre-treatment of freezing and thawing resulted in an increase of sample transparency and juice color intensity. The originality of this development involves the use of freezing and thawing of the pulp as a new form of pre-treatment in juice pressing from raw materials of plant origin. The method can be used in the production of high-quality organic juices.
Most of the advances in fruit juice technology has been associated to developments in enzyme technology. Enzyme preparations have been known to be specific for certain fruits. Glycosidase activities have been observed to effectively solubilize and hydrolyze cell-wall polysaccharides of various fruits. However, some adverse effects have also been noted on structure and color quality. It has been proposed that anthocyanin pigment analysis by means of high-performance liquid chromatography might be a useful means for measuring the activity of various glycosidases.
Four technologies of clear and cloudy juice production according to typical Polish and French procedures were investigated with six apple cultivars. Clear juices were produced using technologies similar to those used by the processing industry, while cloudy juices were processed according to simple protocols used in small-scale processing. In order to best evaluate the effects of the processing technology and cultivar on juice quality, the production of juices was carried out both in Poland and France on the same raw material. The technology, unlike the cultivar, did not affect the soluble solids content of the juice, or the levels of most of the sugars, malic acid or potassium. However, the antioxidant activity measured by the ABTS+ method and the levels of monomeric phenolics and procyanidins strongly depended on the apple cultivar and production technology. For cloudy juices, the selection of appropriate cultivars and production without centrifugation are the key to substantially increasing the amounts of healthy compounds in apple juice.
The effects of freezing rate on the efficiency of the subsequent osmotic extraction and the quality of the osmotically extracted juice from Prunus mume fruits were evaluated. Fresh fruits of P. mume were frozen at -20 or -50 degrees C, thawed, and mixed with sucrose. The juices after osmotic treatment were then prepared from these mixtures. Nonfrozen fruits were used as control. Nominal freezing times were 74 and 28 min for -20 and -50 degrees C, respectively. Drip loss was higher in fruits frozen at -20 degrees C than at -50 degrees C. Clarity and browning index of the juice from frozen fruits were higher and lower, respectively, than those of the nonfrozen fruits. Contents of glucose, fructose, citric acid, tartaric acid, malic acid, and chlorogenic acid in juices ranked in descending order as follows: juice from fruits frozen at -20 degrees C > juice from fruits frozen at -50 degrees C > juice from nonfrozen fruits. These results suggest that freezing pretreatment affected the quality of osmotically extracted juice and that slow freezing could be a more useful method in osmotically extracting fruit juice.
This paper presents a study of the effects of freezing and thawing carrot pulp and pomace on the efficiency of the pressing process and the quality of juice. In this study, various combinations of pretreatment strategies were used based on freezing and thawing the carrot pulp and pomace before pressing. The pressing process for pulp and pomace was carried out using a laboratory press with a perforated base. The juice obtained as a result of freezing and thawing the carrot pulp and pomace was characterized by a higher sugar content (°Brix) and a slightly lower dynamic viscosity. Furthermore, the study showed the impact of pretreatment on the chemical composition of the juice produced. On the basis of energy use and quality indicators of the resultant carrot juice (viscosity, pH, selected minerals, sugars, total carotenoid content, and vitamin C), a recommended solution is to press the pulp directly after grinding the carrots and then to press the pomace again after freezing and thawing. The proposed method for juice production using freezing and thawing allows a reduction in pomace quantity and the use of its valuable nutrients.
Although pectic enzymes have long been used to increase the yield and clarity of fruit juices, it is only recently that technological innovations, such as the use of immobilization supports and continuous-flow systems, have been considered to optimize these fruit processing procedures. To our knowledge, this is the first review to focus on the benefits brought to the field by these new technologies and their potential for commercial applications.
The effects of different enzymatic preparations on total phenolic content, phenolic profile (HPLC), and ferric reducing antioxidant power (FRAP) of cloudy juices from Lis Gala and Fuji Suprema apples varieties, at three ripening stages (unripe, ripe and senescent) were investigated using Principal Component Analysis and Hierarchical Cluster Analysis. The commercial preparations enzymatic (Ultrazym® AFPL; Pectinex® Ultra Clear; Pectinex® SMASH XXL; Panzym® YieldMASH) increased the total phenolic compounds and ferric reducing capacity of the cloudy juice from unripe and ripe Lis Gala (respectively by 67 and 49% for unripe apples, and 28 and 33% for ripe apples) and unripe Fuji Suprema apples (23 and 55%), while for the ripe Fuji Suprema apples only Pectinex® Ultra Clear and Panzym® YieldMASH had this effect. No significant (p > 0.05) was observed on senescent stage, whatever the enzymatic preparation. Enzymatic preparations could increase phenolic compounds concentration and antioxidant capacity of cloudy apple juice, but this effect depended on the maturity of the apples.
The total phenolic, flavanol, monomeric anthocyanin contents and the antioxidant activity of flesh and peel of 11 apple cultivars from Brazil were investigated. Concentrations of the parameters measured differed significantly among the apple cultivars and were highest in the peel compared to the flesh. Total phenolic content (mg GAE/100g fresh matter) ranged from 128.3 (Golden Delicious) to 212.0 (Epagri-F5P283) in the flesh and 304.6 (Golden Delicious) to 712.6 (Catarina) in the peel. Total flavanol content (mg CAE/100g fm) varied from 11.7 (Epagri-SJ11) to 28.2 (Epagri-F43P23) and from 32.4 (Epagri-SJ11) to 147.7 (Catarina) in the flesh and peel, respectively. COOP-24 peel had the highest total anthocyanin content. The Epagri-F5P283 and Epagri-F43P23 flesh and Catarina peel had the highest antioxidant activity while Golden Delicious flesh and peel had the lowest. The total phenolic content and antioxidant activity were significantly correlated in both flesh (R2=0.717) and peel (R2=0.716). The contribution of phenolics to the antioxidant activity in peel suggests that their removal may induce a significant loss of antioxidants.
This work compares the efficiency of extraction and stability of extracts from mushroom (Agaricus bisporus) for different methods of extraction: pressure extraction (PE), pressure extraction assisted by pulsed electric field (PE + PEF), hot water extraction (WE; temperature, T = 343 K, time, t = 2 h), ethanol extraction (EE; T = 298 K, t = 24 h), and supplementary ethanol extraction from cakes of slices (SEE; T = 298 K, t = 24 h). PE was done at room temperature and 5 bar pressure (p). PEF treatment was done using bipolar near-rectangular pulse protocol. The traditional hot WE (T = 343 K, t = 2 h) gave the relatively high contents of proteins, total polyphenols and polysaccharides; however, the extracts were cloudy and their colloid stability was low. The extracts obtained using EE method were also cloudy and unstable. The sizes of particles in extracts, produced by WE and EE methods, were estimated as ≈ 0.25 and ≈ 5 μm, respectively. From the other side, the extracts, produced by PE and PE + PEF methods, were clear and their colloid stability was high. Moreover, both PE and PE + PEF methods allowed selective separation of different components. The PE + PEF method gave higher nucleic acid/proteins ratio as compared with that of PE method. Moreover, PE + PEF allowed production of mushroom extracts with high contents of fresh-like proteins and polysaccharides. Application of the EE method supplementary to the PE or PE + PEF techniques allowed for an effective extraction of the total polyphenols that was comparable with the efficiency of the WE method. © 2013 Springer Science+Business Media New York.
Publisher Summary This chapter discusses the analysis of total phenols and other oxidation substrates and antioxidants by means of Folin-Ciocalteu reagent. Analyses of the Folin-Ciocalteu (FC) type are convenient, simple, and require only common equipment and have produced a large body of comparable data. Under proper conditions, the assay is inclusive of monophenols and gives predictable reactions with the types of phenols found in nature. Because different phenols react to different degrees, expression of the results as a single number—such as milligrams per liter gallic acid equivalence—is necessarily arbitrary. Because the reaction is independent, quantitative, and predictable, analysis of a mixture of phenols can be recalculated in terms of any other standard. The assay measures all compounds readily oxidizable under the reaction conditions and its very inclusiveness allows certain substances to also react that are either not phenols or seldom thought of as phenols (e.g., proteins). Judicious use of the assay—with consideration of potential interferences in particular samples and prior study if necessary—can lead to very informative results. Aggregate analysis of this type is an important supplement to and often more informative than reems of data difficult to summarize from various techniques, such as high-performance liquid chromatography (HPLC) that separate a large number of individual compounds .The predictable reaction of components in a mixture makes it possible to determine a single reactant by other means and to calculate its contribution to the total FC phenol content. Relative insensitivity of the FC analysis to many adsorbents and precipitants makes differential assay—before and after several different treatments—informative.
The aim of the investigation was evaluation of phenolic compounds content, measured by HPLC method at selected stages of clear apple juice production with pectolytic mash enzymation from ‘Shampion’ and ‘Idared’ apples. Sum of phenolic compounds in ‘Shampion’ mash was significantly higher than in ‘Idared’ mash, 520 and 352 mg kg−1, respectively. Enzymation of ‘Idared’ mash resulted in a higher phenolic compounds decrease compared to ‘Shampion’, 23% and 14% respectively. Sum of phenolics in juices from ‘Shampion’ for Panzym at 50 °C (366 mg kg−1) was significantly higher than in juices from ‘Shampion’ for Rohapect at 20 °C and ‘Idared’ for Panzym at 50 °C (256 and 234 mg kg−1, respectively). The lowest phenolics (95 mg kg−1) was in juices from ‘Idared’ for Rohapect at 20 °C. There was a positive correlation (R2 = 0.933) between phenolics content and antioxidant activity of juices (ABTS?+). In general, enzymation at 50 °C with Panzym lead to a higher content of the phenolic compounds in juices compared to Rohapect at 20 °C.
Five apple juices were produced on a pilot scale by crushing the fruit, treating the mash with pectolytic enzymes, pressing, extracting water from the pomace, pasteurization, treatment of the juice with enzymes, combined gelatin/silica sol fining and final ultrafiltration. The temperature of the mash treatment was either ambient or one of 30, 40, 50 or 60 °C, in order to test whether this led to different compositional changes in the corresponding juices. The main emphasis was put on detection of D-galacturonic acid as the indicator substance for the extent of the enzymatic treatment. In the pasteurized raw juices after pressing we found values from 226 to 398 mg L−1. A distinct increase of the galacturonic acid levels could be observed during the clarification steps. Enzymatic juice treatment raised the concentrations to 580–720 mg L−1. After ultrafiltration, final values of 790–1100 mg L−1 were measured. Generally, the highest values were found in the 50 °C sample, which is the optimum temperature for pectinase activity. This was also true for the colloid concentrations and polyphenols. The influence of the temperature of the enzymatic mash treatment on other characteristic juice parameters like total titratable acidity, density, sugar, and minerals concentrations was low.
Cylindrical gelatin gels were frozen at atmospheric pressure with different operating conditions (air-blast freezing at different air temperatures and brine freezing). A method to calculate a local freezing rate was proposed to take into account the variation of freezing rate as a function of the radius. A linear evolution of the local freezing rate according to the radius was observed whatever the freezing process was. Frozen gels were freeze-dried and sliced perpendicularly to the heat flux. The ice crystal marks were measured according to the radial position with image analysis software. Each radial distribution of ice crystal size was characterised by the mean representative diameter. A linear regression permitted to link the ice crystal mean representative diameter to the radial position. On addition, the variation in the mean diameter with the local freezing rate was fitted by a power law.
Clear and cloudy apple juices from Idared and Champion varieties were studied for their radical-scavenging effects. The polyphenolic content and composition of the juices before and after thiolysis were determined by high-performance liquid chromatography with diode array detection. Cloudy juices, especially that prepared from Champion variety, had a higher content of procyanidins than clear juices. Radical-scavenging activity was measured by electron paramagnetic resonance (EPR) spectroscopy using the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. All juices showed long-lasting radical-scavenging activity, and EPR spectra were recorded over time to follow the reaction kinetics. Scavenging of DPPH showed pseudo-first-order kinetics, which might be expected in the presence of polymerised antioxidants that prevent closer contact between the DPPH radical and hydroxyl groups. The content of polymeric procyanidins showed a linear dependence on the rate constant, suggesting that these compounds are mainly responsible for time-extended radical-scavenging activity. The antioxidant properties of apple juices were much better reproduced by EPR spectroscopy than by UV–visible measurements. The former method is especially sensitive to the concentration of polymerised or bound procyanidins, whilst the latter method requires transparent (clear) samples. Apple juices, especially cloudy ones, are a rich source of natural antioxidants that may be used in the pharmaceutical or food industry. Copyright © 2006 Society of Chemical Industry
The textural quality of carrots subjected to pretreatments affecting the pectin structure in combination with different freezing
conditions was studied. Carrot samples frozen under different conditions were extensively studied by light microscopy quantifying
the freezing damage based on the analysis of different parameters (number, area, perimeter, and shape factor of tissue particles)
associated with carrot tissue damage. The reduced texture loss of rapidly or cryogenically frozen carrots, compared to slowly
frozen samples, was associated with the reduction in cell wall damage in the carrot tissue. In case no pretreatment was used,
carrot texture was only slightly improved by using high-pressure shift freezing instead of slow freezing. Detailed analysis
of the different steps involved showed that severe tissue damage occurred during the completion of the high-pressure freezing
process at atmospheric pressure. However, tissue damage, and thus texture loss, of high-pressure frozen carrots could be minimized
by applying pretreatments consisting of a thermal treatment at 60°C and a high-pressure treatment at 300MPa and 60°C.
Apple juices, obtained by straight pressing, pulp enzyming or liquefaction and clarification by the conventional process using bentonite, gelatin, and silicasol or by ultrafiltration, were analysed for sugar and acid content, colour, polyphenol content, ultrafiltration fluxes and polysaccharide content and composition. The amount and composition of the high-M
r polysaccharide fractions found indicate the importance of the juice processing method and enzyme preparation chosen. Polysaccharides solubilized from the cell walls were found to contain galacturonic acid and arabinose as the major constituent sugars. Ultrafiltration enabled the removal of high-M
R polymers but neutral arabinans were still found to be present in ultrafiltered juice.In verschiedenen Apfelsften, die durch direkte Pressung, enzymatische Pulpbehandlung oder Verflssigung und auf konventionelle Weise mittels Bentonit, Gelatine und Silicasol oder durch Ultrafiltration geklrt wurden, wurden der Zucker- und Suregehalt, die Farbe, der Polyphenolgehalt, die Ultrafiltrations-Durchflugeschwindigkeit und der Gehalt und die Zusammensetzung der Polysaccharide bestimmt. Die Menge und Zusammensetzung der gefundenen hochmolekularen Polysaccharid-Fraktionen zeigen deutlich die Bedeutung der Herstellungsmethode und der verwendeten Enzymprparate. Galakturonsure und Arabinose waren die Hauptbestandteile der aus den Zellwnden gelsten Polysaccharide. Die Ultrafiltration ermglichte die Abtrennung von hochmolekularen Polymeren; jedoch wurden auch in ultrafiltrierten Sften noch neutrale Arabinane nachgewiesen.
The purpose of this study was to investigate the comparative clarification techniques in apple juice processing and their effects on the patulin content and some other quality parameters including phenolic compounds and organic acids.
The clarification techniques varied significantly in their effects for the removal of patulin from apple juice. Conventional clarification using gelatin, bentonite, and activated charcoal was found to be more effective than others. However, this technique also caused a significant decrease in apple juice phenolics adversely affecting the juice authenticity. Adsorbent resin treatment just after ultrafiltration also resulted in a remarkable decrease in patulin and brought an improvement in juice color and clarity. PVPP itself had no observable effect on patulin, but specifically adsorbed apple juice phenolics. Organic acid compositions of the samples were not significantly affected from the clarification techniques applied in this study.
The variation in the antioxidant content and the associations that may exist with harvest quality characteristics in peel and flesh tissue from seven apple cultivars were studied. Total antioxidant activity, total phenolic and ascorbic acid content, total soluble solids, total acidity and color parameters were measured in flesh and peel fruit tissues from the apple cultivars Fuji, Golden Delicious, Granny Smith, Jonagored, Mutsu, Starkrimson and Fyriki. In flesh tissue, Fyriki contained the highest antioxidant activity and total phenolic content (up to 82% and 67% more, respectively), while the lowest values were found in Fuji, Golden Delicious and Granny Smith. The ascorbic acid content was also greatest in the flesh tissue of Fyriki (up to 36% more). In peel tissue, the greatest antioxidant activity and total phenolic content were found in Starkrimson (up to 64% more) whereas the lowest values were found in Golden Delicious and Granny Smith. Apple peel contain from 1.5 to 9.2 times greater total antioxidant activity and from 1.2 to 3.3 times greater total phenolic content compared with flesh. Principal component analysis and correlation analysis showed that a more nutritious peel may be darker, redder and bluer, while a more nutritious flesh may have a lighter color and lower soluble solid content. It is concluded that Starkimson and the local cultivar Fyriki should be regarded as a valuable source of antioxidants, while fruit harvest quality characteristics may suggest for nutritional properties of apple.
The partial compositional characteristics were determined for apple juice from 175 non-commercial varieties of apples developed from scion wood collected from approximately 12 countries and several USA geographical areas. Juices from many of the varieties were high in malic acid and potassium. Mean values for many of the attributes did not match existing compositional database value means. However, some of the overall minimum and maximum values for the various attributes (i.e., Brix°, pH, ash, TA, sucrose, glucose, fructose, sorbitol, malic, citric, fumaric, sodium, and calcium) in this study compared reasonably well with existing compositional database values. Distribution of phenolics between the various varieties was highly variable with some juices containing little if any phenolic compounds. Chlorogenic acid and phloridzin were detected in all varietal samples while arbutin and HMF were not measurable. The data developed should be useful with other databases in describing authentic apple juice and in the development of future apple commercial varieties to target specific consumer requirements.
The effects of different commercial enzymatic mash treatments on yield, turbidity, color, and polyphenolic and sediment of procyanidins content of cloudy apple juice were studied. Addition of pectolytic enzymes to mash treatment had positive effect on the production of cloud apple juices by improving polyphenolic contents, especially procyanidins and juice yields (68.3% in control samples to 77% after Pectinex Yield Mash). As summary of the effect of enzymatic mash treatment, polyphenol contents in cloudy apple juices significantly increased after Pectinex Yield Mash, Pectinex Smash XXL, and Pectinex XXL maceration were applied but no effect was observed after Pectinex Ultra-SPL I Panzym XXL use, compared to the control samples. The content of polymeric procyanidins represented 50-70% of total polyphenols, but in the present study, polymeric procyanidins were significantly lower in juices than in fruits and also affected by enzymatic treatment (Pectinex AFP L-4 and Panzym Yield Mash) compared to the control samples. The enzymatic treatment decreased procyanidin content in most sediment with the exception of Pectinex Smash XXL and Pectinex AFP L-4. Generally in samples that were treated by pectinase, radical scavenging activity of cloudy apple juices was increased compared to the untreated reference samples. The highest radical scavenging activity was associated with Pectinex Yield Mash, Pectinex Smash XXL, and Pectinex XXL enzyme and the lowest activity with Pectinex Ultra SP-L and Pectinex APFL-4. However, in the case of enzymatic mash treatment cloudy apple juices showed instability of turbidity and low viscosity. These results must be ascribed to the much higher hydrolysis of pectin by enzymatic preparation which is responsible for viscosity. During 6 months of storage at 4 degrees C small changes in analyzed parameters of apple juices were observed.
Partially depectinated apple cell walls were digested by pectin lyase or endoglucanase or a combination. By combining these commercial enzymes, a higher yield of 22.2% of carbohydrate material was obtained compared with only 13.9% and 5.7%, respectively, when using them singly. Only small amounts of carbohydrates were extracted by buffer (0.8%). The solubilized extracts were fractionated using a combination of ion-exchange chromatography and gel filtration. The individual subfractions were analysed for neutral sugar and uronic acid content. The results indicated the existence of a synergistic effect between pectin lyase and endoglucanase based on the percentage of material extracted.
Consumption of fruits and vegetables has been shown to be effective in the prevention of chronic diseases. These benefits are often attributed to the high antioxidant content of some plant foods. Apples are commonly eaten and are large contributors of phenolic compounds in European and North American diets. The peels of apples, in particular, are high in phenolics. During applesauce and canned apple manufacture, the antioxidant-rich peels of apples are discarded. To determine if a useful source of antioxidants is being wasted, the phytochemical content, antioxidant activity, and antiproliferative activity of the peels of four varieties of apples (Rome Beauty, Idared, Cortland, and Golden Delicious) commonly used in applesauce production in New York state were investigated. The values of the peels were compared to those of the flesh and flesh + peel components of the apples. Within each variety, the total phenolic and flavonoid contents were highest in the peels, followed by the flesh + peel and the flesh. Idared and Rome Beauty apple peels had the highest total phenolic contents (588.9 +/- 83.2 and 500.2 +/- 13.7 mg of gallic acid equivalents/100 g of peels, respectively). Rome Beauty and Idared peels were also highest in flavonoids (306.1 +/- 6.7 and 303.2 +/- 41.5 mg of catechin equivalents/100 g of peels, respectively). Of the four varieties, Idared apple peels had the most anthocyanins, with 26.8 +/- 6.5 mg of cyanidin 3-glucoside equivalents/100 g of peels. The peels all had significantly higher total antioxidant activities than the flesh + peel and flesh of the apple varieties examined. Idared peels had the greatest antioxidant activity (312.2 +/- 9.8 micromol of vitamin C equivalents/g of peels). Apple peels were also shown to more effectively inhibit the growth of HepG(2) human liver cancer cells than the other apple components. Rome Beauty apple peels showed the most bioactivity, inhibiting cell proliferation by 50% at the low concentration of 12.4 +/- 0.4 mg of peels/mL. The high content of phenolic compounds, antioxidant activity, and antiproliferative activity of apple peels indicate that they may impart health benefits when consumed and should be regarded as a valuable source of antioxidants.
The relationship between phenolic composition and radical scavenging activity of apple peel and pulp was investigated in fruit produced according to both organic and integrated agricultural methods. Apple tissue extracts were subjected to high-performance liquid chromatography separation, which showed that as compared with pulps, peels are richer in almost all of the quantified phenolics. Flavonols, flavanols, procyanidins, dihydrochalcones, and hydroxycinnamates were the identified phenolic classes in peel tissue, and the most abundant compounds were epicatechin, procyanidin B2, and phloridzin. Pulps were poorer in phytochemicals. Their major phenolics were procyanidins and hydroxycinnamates. Flavonols in amounts <20 mg kg(-1) fresh weight (fw) were also found. In both peels and pulps, integrated production samples were richer in polyphenols. Among the 14 compounds identified, only phloridzin had a tendency to appear higher in organic peels. The total antioxidant capacities (TAC) of extracts were evaluated using the 1,1-diphenyl-2-picrylhydrazyl radical assay and were expressed as Trolox equivalents. Integrated peels gave the highest TAC (18.56 mM kg(-1) fw), followed by organic peels (TAC = 14.96), integrated pulps (TAC = 7.12), and organic pulps (TAC = 6.28). In peels, the top contributors to the antioxidant activity were found to be flavonols, flavanols, and procyanidins, which accounted for about 90% of the total calculated activity whereas in pulps, the TAC was primarily derived from flavanols (monomers and polymers) together with hydroxycinnamates. A good correlation between the sum of polyphenols and the radical scavenging activities was found. Among the single classes of compounds, procyanidins (in peels and pulps) and flavonols (in peels) were statistically correlated to the TAC.
The effects of enzymatic mash treatments on yield, turbidity, color, and polyphenolic content of cloudy apple juice were studied. Using HPLC-ESI-MS, cryptochlorogenic acid was identified in cv. Brettacher cloudy apple juice for the first time. Commercial pectolytic enzyme preparations with different levels of secondary protease activity were tested under both oxidative and nonoxidative conditions. Without the addition of ascorbic acid, oxidation substantially decreased chlorogenic acid, epicatechin, and procyanidin B2 contents due to enzymatic browning. The content of chlorogenic acid as the major polyphenolic compound was also influenced by the composition of pectolytic enzyme preparations because the presence of secondary protease activity resulted in a rise of chlorogenic acid. The latter effect was probably due to the inhibited protein-polyphenol interactions, which prevented binding of polyphenolic compounds to the matrix, thus increasing their antioxidative potential. The results obtained clearly demonstrate the advantage of the nonoxidative mash maceration for the production of cloud-stable apple juice with a high polyphenolic content, particularly in a premature processing campaign.
Apples are an important source of flavonoids in the human diet. The effect of processing apples into juice on polyphenolic antioxidant content and activity is described. Raw juice obtained from Jonagold apples by pulping and straight pressing or after pulp enzyming had an antioxidant activity that was only 10 and 3%, respectively, of the activity of the fresh apples. The levels of flavonoids and chlorogenic acid in the juice were reduced to between 50% (chlorogenic acid) and 3% (catechins). Most of the antioxidants were retained in the pomace rather than being transferred into the juice. Apparently, most of the antioxidant compounds are absorbed to the solid matter of the pomace. In apple juice, 45% of the total measured antioxidant activity could be ascribed to the analyzed antioxidants. For three apple cultivars tested (Elstar, Golden Delicious, and Jonagold), the processing methods had similar effects. The results indicate that processing can have a major impact on the bioactivity of products.
Lactic acid fermentation of apples from organic farming as a way to receive a new range of products—bio‐juices
- Chabłowska B
Wydajność tłoczenia i wskaźnik zużycia jabłek w procesie wytwarzania zagęszczonego soku jabłkowego
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Soki cold pressed—światowy trend w sokownictwie
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Przetwórstwo owoców na poziomie gospodarstwa
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- Lesisz JT
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Związki fenolowe – charakterystyka i znaczenie w technologii żywności
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Effect of enzymatic hydrolysis on the juice yield from apple fruit (Malus domestica)
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- Erickson