No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Effect of high-pressure short-time processing on the physicochemical properties of abalone (Haliotis discus hannai) during refrigerated storage
Abstract
This study investigated the effects of high pressure short-time processing on the physicochemical and microbial characteristics of abalone during chilled storage. Pressurization at 200 MPa caused a decrease in pH and shear force compared to those in the control but thereafter increased with increasing pressure levels. Water holding capacity (WHC) of abalone decreased when pressurized at > 400 MPa. A greater reduction in shear force was observed after 1 week of storage. For color, reduction in the a* value of abalone was considerable during storage. Increasing pressure suppressed the generation of total volatile basic nitrogen compounds and total viable counts, whereas lipid oxidation occurred with increasing pressure. Pressurization at 200 MPa was the optimum pressure condition in which the shelf-life of abalone was extended to about 10 days compared to 3 days in the control.
Industrial relevance
For the use of high pressure as a pasteurization technique, commercial system is required not to exceed 5 min of holding time for the system maintenance purpose. In addition, this process is carried out under ambient temperature for the economical aspect. Abalone which is normally consumed as raw state in East Asia has very short shelf-life (< 3 days) during chilled storage, hence increasing the shelf-life for 7–8 days has been challenged for commercial distribution of the abalone. This study provided one of strategy to extend shelflife of abalone with minimal quality changes by high pressure processing.
... However, these critical characteristics of meat quality would be inevitably deteriorated during postmortem storage owing to the action of endogenous enzymes, leading to prime quality loss (De Oliveira et al., 2019). Also, the onset and promotion of protein degradation during postmortem storage triggered by enzymatic action also create ideal conditions for the growth of microorganisms that contaminate muscle and lead to being susceptible to spoilage (Jo et al., 2014). High-pressure processing (HPP) as a non-thermal sterilization technology has been proved to have superior capacities to diminish microbial loads while retaining most of the sensory, nutrient and functional properties of processed food products (Chouhan et al., 2015). ...
... The primary proteins in muscle myofibrils as myosin, actin, tropomyosin and troponin-T play an important role in maintaining muscle structural integrity and fluid retention by myofibrils, and high pressure can induce these cytoskeleton proteins to change and thereby affect meat quality (Campus et al., 2010). Jo et al. (2014) pointed out that the unfolding and denaturation of muscle proteins after highpressure treatments of 400 MPa and 500 MPa for 3 min contributed to the WHC and textural properties of the muscle, and pressurization from 300 MPa to 500 MPa for 3 min could lead to protein unfolding and structural changes in the muscle and compensate for the decline in pH and shear force caused by the acceleration of postmortem glycolysis, thereby resulting in an increase in pH of pressurized post-rigor abalone muscle. Zhang et al. (2015) indicated pressures at <200 MPa induced gel formation of myofibrillar proteins which increased WHC, whereas higher pressures resulted in protein denaturation and reduced WHC. ...
... Meanwhile, a decrease in the a* value of abalone was observed after 2-3 weeks depending on the pressure level (P < 0.05). The abalone treated at <200 MPa showed decreases in a* after 2 weeks of storage, whereas the a* value of those treated at >300 MPa decreased after 3 weeks (Jo et al., 2014). In addition, carp muscle fillets also obtained significantly increased L* values when treated with 140-200 MPa pressures for 15 or 20 min (P < 0.05), while significantly increased b* values could be found when treated with pressures higher than 100 MPa regardless of treatment time (15/ 20 min, P < 0.05) (Sequeira-Munoz et al., 2006). ...
Microbial load, protein oxidation, myofibrillar protein changes and quality characteristics (meat color and water retentiveness including centrifugal loss (CeL) and water-holding capacity (WHC)) of post-rigor tan mutton exposed to different high-pressure treatments (200 MPa/500 MPa for 15 min at 18°C) during chilled storage for 7 days (4°C) were evaluated. High-pressure applications of 200 MPa and 500 MPa significantly reduced the number of Total Viable Counts (TVC) during storage (P < 0.05), but excessive pressure treatment (500 MPa) also resulted in a significant increase in protein oxidation and decrease in water retentiveness (P < 0.05), accompanied by deterioration of meat color. 200 MPa treatment also caused adverse effects on the quality of processed meat at the later stage of storage (3–7 d) similar to 500 MPa high pressure, but the initial application of 200 MPa pressure resulted in no significant differences in meat color and retentiveness from the untreated (P > 0.05) and better texture characteristics than untreated samples. ANOVA with Partial Least Squares Regression (APLSR) confirmed the relationshipS between these variations in quality characteristics induced by high-pressure treatments and protein oxidation and key myofibrillar skeleton proteins.
... Despite the limited harvest of wild abalone, explosive consumer demand triggered abalone production via farming. It was generally reported that abalone has high lethality and mortality, and the shelf life of chilled abalone muscle is very limited (~3 days), which accounted for the majority of economic damage to abalone farming ( Chiou et al., 2002;Braid et al., 2005;Jo et al., 2014). Although, freezing or drying techniques have been adopted to extend the shelf life of abalone, these products manifested quality modifications against chilled products. ...
... Based on our previous study (Jo et al., 2014), more than 300 MPa (3 min holding time) was required to achieve the pasteurization effect of chilled abalone, and the shelf-life of abalone could be extended for 10 days via 300 MPa pressurization. ...
... High pressure treatment Each of two sample packages (each three abalones) of a treatment was pressurized using a lab-scale high pressure system as described in our previous study (Jo et al., 2014). In brief, the system consisted of a pressure vessel, pressure generator and pressure intensifier. ...
This study investigated the effects of pressure level, holding time, and storage period on the physicochemical properties of chilled abalone. Pressure level and storage period had a significant effect on the qualities of abalone, while the impact of holding time was negligible compared to those of pressure level and storage period. Pressurization at 400 – 500 MPa had the potential advantage to extend shelf-life of abalone to more than 15 days, while quality modifications were noticeably identified. Moderate pressurization (< 200 MPa) had no effect on the shelf-life of abalone. The optimal processing condition was 200 – 300 MPa at which the shelf-life of abalone could be extended to around 10 days with minimizing quality modification. Although, the mechanisms involved in shelf life extension and quality modification of pressurized abalone were not fully understood, the present study demonstrated the potential application of high pressure in the abalone industry.
... Because abalone is perishable and has a limited shelf-life (2-3 days) under chilled storage, high-pressure processing has attracted significant attention to extend the shelf-life of abalone (Briones, Reyes, Tabilo-Munizaga, & Pérez-Won, 2010). Work by Jo et al. (2014) demonstrated that high-pressure short-time processing (N300 MPa for 3 min) extends the shelf-life of abalone to 7 days in a chilled state. Briones et al. (2010) reported that the microbial shelf life of abalone pressurized at 500-550 MPa for 3-8 min was extended to N65 days. ...
... Briones et al. (2010) reported that the microbial shelf life of abalone pressurized at 500-550 MPa for 3-8 min was extended to N65 days. Furthermore, quality modifications, such as water-holding capacity, color and texture, have also been evaluated in pressure treated abalone (Briones et al., 2010;Briones-Labarca, Perez-Won, Zamarca, Aguilera-Radic, & Tabilo-Munizaga, 2012;Jo et al., 2014). Consumers could recognize the pressure treated abalone as a processed abalone rather than fresh abalone due to quality modifications (Jo et al., 2014). ...
... Furthermore, quality modifications, such as water-holding capacity, color and texture, have also been evaluated in pressure treated abalone (Briones et al., 2010;Briones-Labarca, Perez-Won, Zamarca, Aguilera-Radic, & Tabilo-Munizaga, 2012;Jo et al., 2014). Consumers could recognize the pressure treated abalone as a processed abalone rather than fresh abalone due to quality modifications (Jo et al., 2014). To extend shelf life without severe quality modifications, alternate processing technology is required. ...
This study investigated the effects of high pressure sub-zero temperature (HPST) and pressure-shift freezing (PSF) on the quality characteristics of abalone. Each process was conducted within 0.1–200 MPa. HPST caused high drip loss relative to the control, whereas drip generation was effectively prevented by PSF at 150 MPa. The shear force of abalone treated by HPST exhibited a significant decrease with increasing pressure, whereas abalone treated by PSF maintained shear force values similar to the control. With respect to color, HPST resulted in high redness (a*) without changes in lightness (L*) or yellowness (b*) relative to control. The a* and b* of PSF-treated abalone were similar to control, although low L* was observed in PSF-treated abalone. Regardless of the processing methods, increasing pressure levels tended to decrease the aerobic colony count (ACC) of abalone. Consequently, the results suggested that PSF effectively minimized the quality damage caused by the abalone freezing process and that 150 MPa was the optimal condition for PSF for abalone.
Industrial relevance
Pressure-shift freezing has been recognized as the most rapid freezing technique. Currently, high pressure low temperature (HPLT) processing is adopted by means of long time storage of biomaterials. Nevertheless, one of the problem to apply these technique in actual industry is that the materials have to be kept at normally 200 MPa at which the materials can cooled down to around − 20 °C. Based on this study, it is possible to reduce the processing pressure level (~ 100 MPa) which would provide a practical advantage of HPLT processing as well as industrial applicability.
... Very high pressures (>400 MPa) and longer processing times (5-20 min) can toughen meat due in part to myofibrillar protein denaturation and myosin compression (Duranton, Simonin, Chéret, Guillo, & de Lamballerie, 2012;Zamri, Ledward, & Frazier, 2006). Abalone meat processed at 400 MPa or greater has been shown to have higher chewiness and cohesiveness values and lower water holding capacity compared to unprocessed controls (Briones-Labarca, Pérez-Won, Zamarca, Aguilera-Radic, & Tabilo-Munizaga, 2012;Jo et al., 2014). The rigor status of abalones during processing has recently been reported to impact post-processing texture. ...
... Compared to unprocessed controls, the texture of pre-rigor processed (100 MPa and 300 MPa) abalone toughened, while texture of post-rigor processed abalone did not differ from unprocessed controls (Hughes, Greenberg, Yang, & Skonberg, 2015). HPP has only recently been explored for shelf-life extension of abalone, with very high pressures (P500 MPa) for 5-8 min extending refrigerated shelf-life of abalone to 60-65 days and low pressure (200 MPa) for a short processing time (3 min) extending shelf-life to only 10 days (Briones, Reyes, Tabilo-Munizaga, & Pérez-Won, 2010;Jo et al., 2014). ...
... In a study evaluating pressures below 500 MPa for a short processing time (3 min), HPP abalone had TVBN values of 17.7 mg% after 21 days of refrigerated storage (Jo et al., 2014). Using the same pressure (300 MPa) for a longer processing time (10 min) in the present study resulted in a lower TVBN value (12.51 mg/100 g) after 21 days. ...
High pressure processing (HPP) of post-rigor abalone at 300 MPa for 10 min extended the refrigerated shelf-life to four times that of unprocessed controls. Shucked abalone meats were processed at 100 or 300 MPa for 5 or 10 min, and stored at 2 °C for 35 days. Treatments were analyzed for aerobic plate count (APC), total volatile base nitrogen (TVBN), K-value, biogenic amines, color, and texture. APC did not exceed 106 and TVBN levels remained below 35 mg/100 g for 35 days for the 300 MPa treatments. No biogenic amines were detected in the 300 MPa treatments, but putrescine and cadaverine were detected in the control and 100 MPa treatments. Color and texture were not affected by HPP or storage time. These results indicate that post-rigor processing at 300 MPa for 10 min can significantly increase refrigerated shelf-life of abalone without affecting chemical or physical quality characteristics important to consumers.
... It is important to understand the effects of HP on fish colour, as colour is one of the main attributes for considering freshness, perception of product quality and influence on the purchase decision of consumers. Several studies have reported that the L* values increase in HP treated fish, which appeared more clear, typical of cooked meat characteristics and grey when exposed to 150-300 MPa (Cheret et al., 2005;de Oliveira et al., 2017;Jo et al., 2014;Truong et al., 2015;Yagiz et al., 2007). HP processed black tiger shrimp gave a significant increase in L* parameters with increased pressure intensity. ...
... A stronger catalytic oxidation power at a pressure level of 300 MPa was reported, even though higher levels of thiobarbituric acid (TBA) were detected from 150-300 MPa in salmon, carp, bonito fish, cod, sea bass, and mahi-mahi(Angsupanich & Ledward, 1998;Lakshmanan, Patterson & Piggott, 2005;Medina-Meza, Barnaba & Barbosa-Canovas, 2014;Sequeira-Munoz, Chevalier, LeBail, Ramaswamy & Simpson, 2006;Teixeira et al., 2014;Wada & Ogawa, 1996;Yagiz, Kristinsson, Balaban & Marshall, 2007). Conversely, smoked fish showed more stability to lipid oxidation after pressure treatment, most likely due to antioxidants derived from the smoke(Jo et al., 2014;Montiel, De Alba, Bravo, Gaya & Medina, 2012).Kaur et al. (2013) reported that the HP treatment of black tiger shrimp at 100, 270 and 435 MPa for 5 min at 25 o C did not significantly change the free fatty acids (FFA) content, indicating that HP did not affect the hydrolysis mechanism of fatty acids. Similar results were observed in mackerel, turbot and salmon(Chevalier, Le Bail & Ghoul, 2001;Figueiredo, Bragagnolo, Skibsted & Orlien, 2015;Ortea, Rodriguez, Tabilo-Munizaga, Perez-Won & Aubourg, 2010). ...
Consumer trends towards shelf-stable, safe, more natural and free from additives foods drove the need
to investigate the commercial application of non-thermal food processing technologies. High pressure
processing (HPP) is one such emerging technology where foods are generally subjected to high pressure
(100-1000 MPa), with or without heat. Similar to heat pasteurization, HPP deactivates pathogenic
microorganisms and enzymes, extends shelf life, denatures proteins, and modifies structure and texture
of foods. However, unlike thermal processing, HPP can retain the quality of fresh food products, with
little or no impact on nutritional value and organoleptic properties. Moreover, HPP is independent
of the geometry (shape and size) of food products. The retention of food quality attributes, whilst
prolonging shelf life, are enormous benefits to both food manufacturers and consumers. Researches
have indicated that the combination of HPP and other treatments, based on the hurdle technology
concept, has potential synergistic effects. With further advancement of the technology and its largescale commercialization, the cost and limitations of this technology will probably reduce in the near
future. The current review focuses on the mechanism and system of HPP and its applications in the
processing of fruit, vegetables, meat, milk, fish and seafood, and eggs and their derived products.
... Abalone is an expensive seafood, which is not only a highly sought delicacy with unique taste and texture, but also has many health benefits like fatigue recovery, and detoxification (Jo et al., 2014). In New Zealand, there are three endemic species of abalone, blackfoot abalone (Haliotis iris), yellowfoot abalone (Haliotis australis) and whitefoot abalone (Haliotis virginea). ...
... Among these species, blackfoot abalone is the only species that is widely farmed for aquaculture due to its higher weight of meat, and larger iridescent shell size, which have high commercial values (Allsopp, Cruz, Flores-Aguilar, & Watts, 2011). Fresh abalone only has a shelf life of between 2-3 days in the refrigerator (Jo et al., 2014). They are commonly processed either frozen, chilled or vacuum-packed forms for export. ...
The effects of pulsed electric field (PEF) processing (0.66, 1.38 and 2.00 kV/cm, 50 Hz) with and without heat treatments (70, 80 and 90 °C for 15 min) on color, texture profile, lipid oxidation value, free amino acids (FFAs) and fatty acids (FAs) content of abalone muscle were studied. PEF treatments had less effects on the physical and chemical characteristics of heated and non-heated samples. Heat treatments however significantly changed meat color, as well as increased toughness and elasticity. In addition, lipid oxidation, and free amino acids (FAAs), and saturated fatty acids (SFAs) content of non-PEF treated samples increased.
... Abalone aquaculture began in the 1960s in the United States and Japan (McBride, 1998) and has since become a well-established industry in China, Korea, Australia, Chile, USA, Mexico and New Zealand (Flores-Aguilar et al., 2007;Allsopp et al., 2012). More than 90% of the world abalone production is based on farming (Jo et al., 2014). China is one of the world's primary abalone-producing countries, with production of 110380 t during 2013 (Chinese fishery statistical yearbook, 2014). ...
... Abalone aquaculture is an intensive industry, which is often land-based, with tanks stocked at high density. Given the crowding and suboptimal environmental conditions compared with conditions in the wild (Shepherd, 1973;Goodsell et al., 2006;Gorski and Nugegoda, 2006), abalones in aquaculture systems are vulnerable to infection by microorganisms that are often ubiquitous (Jo et al., 2014). ...
Foot pustule disease is an important disease affecting abalones. In the present study, microbiological and histopathological investigations were carried out in the Japanese abalone Haliotis discus hannai, affected by foot pustule disease. Diseased abalones became lethargic, weak, and eventually died. The remarkable symptoms were apparent foot pustules and atrophy of the foot muscle. A predominant bacterium designated as BV2 was isolated from the pustules of diseased abalones. Experimental infection by immersion challenge showed that BV2 was virulent to abalones and caused symptoms of foot pustule disease with median lethal dose value of ≈7.76×10⁵ cfu ml⁻¹. BV2 was infectious to all tested abalones with high mortality. Histopathological investigations showed degeneration and collapse of foot muscles as well as connective tissues. Tissues in round pustules were necrotic and disorganised. The BV2 bacterium was identified as Vibrio harveyi based on the results of phenotypic and biochemical tests as well as 16S rRNA gene sequence analysis.. The bacterium was found resistant to kanamycin and clindamycin, and sensitive to other 11 antibiotics tested. © 2018, Indian Council of Agricultural Research. All rights reserved.
... The death of abalone juveniles due to disease and environmental factors is a serious threat to the sustainability of the abalone farming industry and has dealt a heavy blow to the industry [3,4]. The health of abalone is largely influenced by the water environment and its intestinal microbial community [5]. Dramatic changes in the structure of the bacterial community can lead directly to the development of disease, causing huge economic losses to aquaculturists [6]. ...
Bacteria are an integral component of their host. However, information about the microbiota living in and around many aquatic animals is lacking. In this study, multiplex bar-coded pyrosequencing of the 16S ribosomal RNA gene was used to monitor the dynamics of abalone, Haliotis discus hannai, bacterial communities in the intestine, water from cement culture ponds, and surrounding sea areas. Correlations between the bacterial communities and common aquaculture diseases were also evaluated. A total of 329,798 valid sequences and 15,277 operational taxonomic units (OTUs) from 32 samples were obtained by 454 tag amplicon pyrosequencing. The Shannon indices of the seawater samples ranged from 2.84 to 5.6 and the Shannon indices of the abalone intestine samples ranged from 1.2 to 5.12, which were much lower than those of seawater. The dominant phyla in seawater samples were Proteobacteria, Bacteroidetes, Fusobacteria, Cyanobacteria, etc. The dominant phyla in the abalone intestine varied greatly in different months. The dominant genera in the seawater of the cement culture ponds changed in different months, mainly Psychrilyobacter and Pseudoalteromonas. The dominant genera in seawater from the open sea vary considerably between months. The dominant genus of bacteria in the abalone intestine during the months when abalones are susceptible to disease is mainly Mycoplasma spp. Canonical correspondence analysis revealed that bacterial communities in seawater and the intestine responded differently to environmental variables, with similar microbiota in the same area. pH, dissolved oxygen concentration, and temperature were closely related to the samples from the sea area. Oxidation-reduction potential, salinity, phosphate, nitrate, and ammonia nitrogen concentrations were closely related to the water samples from the artificial pools. These findings may add significantly to our understanding of the complex interactions between microbiota and environmental variables in the abalone intestine as well as in the surrounding seawater.
... HP treatment has been demonstrated to inactivate a wide range of food pathogens and endogenous enzymes that cause spoilage and to extend the shelf-life with a minimum impact on sensory and other quality parameters (Considine et al., 2008;Reyes et al., 2015). Furthermore, it has been reported that pressures higher than 400 MPa were adequate to inactivate the spoilage microbes of the abalone muscle, and the physicochemical and sensory characteristics remained unaffected at below 300 MPa (Jo et al., 2014). While studying the effect of HP on the rigor status of abalone fish, Hughes et al. (2015) observed that a pressure/time combination of 300 MPa/5 min caused significant toughening of pre-rigor meat; however, the texture of post-rigor processed abalone was not changed significantly. ...
This work describes the optimization of the pressure-time combination for the inactivation of Listeria monocytogenes in fish medium using a wide range of pressure (225-525 MPa) and holding time (5-30 min). Thereafter, the yellowfin seabream (Acanthopagrus arabicus) fillets (100 g each) were subjected to high-pressure (HP) treatment at the optimum pressure/time combination and assessed the impact of HP on the amino acid profile, fatty acid profiles, color and texture. Glycine, glutamic acid and alanine were recorded as the major amino acids, which did not change significantly after pressurization. Conversely, alanine – the leading free amino acid dropped significantly after treatment. Fatty acid analysis indicated that oleic acid and palmitic acid accounted for 29.88% and 25.59% of the total fatty acids, respectively. Pressurization did not influence the fatty acid profiles, nutritional quality indices, and hardness of yellowfin seabream fish. The color pigments of fillets, measured as a* and b* changed significantly after the treatment. Overall, the work indicates that the HP-treatment can be utilized to maintain the nutritional quality of seabream fillets; however, further research is needed to maintain the visual color of fish.
... They confirmed that the quality indices of abalone muscle were significantly different from those of raw abalone meat. Jo et al. (2014) stated that pressures > 400 MPa are required to inactivate the spoilage microbiota of abalone muscle; when pressure is < 300 MPa, physicochemical and sensory characteristics are not affected. On the other hand, Hughes et al. (2015) evaluated the effects of rigor status during HHP (100 MPa and 300 MPa for 1, 3, and 5 min) on colour, texture, and ultrastructure of abalone meat. ...
The protein secondary structure modifications and digestibility of red abalone muscle subjected to high hydrostatic pressure (HHP) treatments (200, 300, 400, and 500 MPa for 5 min) were evaluated. The protein structure was analysed by Fourier-Transformed Infrared spectroscopy. Protein digestibility was evaluated based on the degree of hydrolysis (DH) and peptide size distributions under in vitro gastrointestinal conditions. The intermolecular β-sheet structure was disrupted at 200 MPa, compensated by the formation of the intramolecular β-sheet. At 300 and 400 MPa, the β-sheet structure can fold on itself from the interactions that stabilize the protein structure. The 310-helix structure was significantly looser at 300 MPa. Structural modifications were accompanied by β-turn formation at 300, 400, and 500 MPa. In vitro gastrointestinal digestion is improved by HHP independently of pressure level. The results suggest that high pressure improve the DH of red abalone as a consequence of β-sheet and β-turn conformations changes.
Industrial relevance
The seafood industry uses high hydrostatic pressure (HHP) technology to reduce undesirable sensory changes and preserve the functional and nutritional properties of compounds. The HHP experiments contributed to unravel the impact of the different level pressure on digestibility. HHP treatment can change the secondary structures of proteins and improve the protein digestibility as function the pressure level. The results of this study provide valuable information for the potential application of HHP on the development of red abalone with high-nutritional value.
... Lipid hydrolysis was inhibited in frozen mackerel by increasing both the pressure level (150, 300, 450 MPa) and the pressure holding time (0.0, 2.5, 5.0 min) for HPP treatment as indicated by a marked inhibition of free fatty acid content throughout 3 months of frozen storage at −10°C (Torres, Vázquez, Saraiva, Gallardo, & Aubourg, 2013). Shelf-life of abalone (Haliotis discus hannai) during refrigerated storage was extended by 10 days, compared to 3 days in the control after pretreatment with high-pressure (200 MPa) for a short time (5 min; Jo et al., 2014). Uçak and Gökoǧlu (2016) reported that pressure between 100 and 300 MPa yielded marinated herring (Clupea harengus) with acceptable taste, texture, and appearance. ...
... Pressures under 200 MPa induce gel formation of myofibrillar proteins which increase the WHC, whereas higher pressures result in protein denaturation and reduced WHC (Zhang, Yang, Tang, Chen, & You, 2015). This has been reported in fish, where pressures over 300 MPa resulted in reduced WHC (Chéret et al., 2005;Jo et al., 2014) or in protein denaturation (Angsupanich, Edde, & Ledward, 1999;Angsupanich & Ledward, 1998). All HHP treated samples showed a decrease in WHC during the first 14 days' storage as it was shown in cod treated at 500 MPa (Christensen, Hovda, & Rode, 2017). ...
... Each analysis was repeated three times with three fishes, with the averages of each replicate used to measure the overall quality of fish. Colour is one of the key parameters used to evaluate the quality of aquatic products and the typically essential factor for deciding the acceptance of aquatic products by consumers (Jo et al., 2014). The colour of pomfret samples were measured with a colorimeter (CR-400, Konica Minolta (China) Investment Ltd. Shanghai, China) in the reflectance mode which was calibrated with a white standard plate at room temperature. ...
This study investigated the physical (L*, a*, b*, texture profile analyses, pH), chemical (TVB-N, K value and TBA), microbiological, amino acid content, and flavor effects that Gingko biloba leaf extract (GBLE) had on silver pomfret (Pampus argenteus) stored at 4 ± 1 °C in ice for 18 days. Fresh pomfret samples were obtained directly from the local fish market and transported to the laboratory with ice immediately. After being gutted, washed, filleted and trimmed in a water-ice mixture, samples were treated with different concentrations of GBLE (0.0 mg/mL, 2.5 mg/mL, 5.0 mg/mL, 10.0 mg/mL) and packaged in Polyethylene bag, then stored in a refrigerator at 4 ± 1 °C with ice. The results show that the shelf-life of untreated (0.0 mg/mL) pomfret samples was 8–9 days compared to 14–15 days for the GBLE1 (2.5 mg/mL) treated group. The assessment results showed that different concentrations of GBLE had variable effects on preserving the texture parameters of acceptability limit, inhibit lipid oxidation, protein degradation, and microorganism growth. 2.5 mg/mL of GBLE was the best for the preservation of pomfret during storage in ice. Therefore, there is potential use for GBLE as a preservative to extend the shelf-life of pomfret during chilled storage in ice.
... In general, the TPC of PSF treatments tended to decrease with increasing pressure levels up to 100 MPa (P < 0.05), thereafter, no significant difference was observed. Based on the study of Jo et al. (2014), a significant decrease in the TPC of abalone was shown at > 300 MPa of high-pressure treatment (at ambient temperature for 3 min), and complete inactivation was obtained at > 400 MPa. In this study, however, PSF treatment at 200 MPa reduced 1.4 log cycles, which was not enough to suggest PSF as a pasteurization technique. ...
This study investigated the effect of various pressure-shift freezing (PSF) conditions (0.1–200 MPa) on the quality characteristics of pork. Pork was pressurized and cooled down to corresponding freezing temperature at given pressure level, and thereafter, the pork was finally frozen in a −50 °C freezer for 24 h. The frozen pork was thawed in a 4 °C refrigerator for 24 h, and quality parameters were analyzed. As quality parameters, pH, water-binding properties, shear force, histological change and color were evaluated. The PSF operating at higher pressure than 150 MPa manifested high moisture loss and discoloration, while the PSF at 50 MPa had no advantageous effect on the quality of pork compared to atmospheric freezing (0.1 MPa). The best PSF condition was observed at 100 MPa, where the pork quality did not differ from an unfrozen control after thawing. Consequently, the results reflected that PSF at 100 MPa had a potential application in providing rapid freezing without quality deterioration in the frozen meat industry.
... Pink perch sausages treated at higher pressures of 500 MPa (23.18%) and 600 MPa (20.63%) showed slightly higher expressible moisture than 400 MPa (18.08%) and control (13.38%). Jo et al. [24] found that WHC of abalone decreased when pressurized at > 400 MPa, which indicates a similar trend of increase in expressible moisture with an increase in pressure. Heat-treated sausage samples showed lower expressible moisture than pressure-treated samples. ...
The non-thermal high pressure (HP) processing was studied on fish sausage to enhance the quality during chilled storage. Pink perch (Nemipterus japonicus) sausages, packed in poly amide casing under vacuum were subjected to 400, 500 and 600 MPa pressures (dwell time: 10 min and ramp rate: 300 MPa/min) and compared with heat-set samples for physico-chemical and microbial quality parameters. Pressurized samples formed softer and glossier gels with a slight reduction in water-holding capacity. HP made the texture of sausage softer, cohesive and less chewy and gummier than heat-treated ones. Folding test seen higher acceptance values in samples treated at 500 and 600 MPa, during storage. Maximum log reduction in microbial count was observed in 600 MPa immediately, and significant difference in cooked and pressurized sausages was seen only up to 7th day. This revealed the potential application of HP in replacing conventional heat treatment for sausages preparation with enhanced shelf-life.
The objective of this study was to assess the quality parameters of hammour (Epinephelus coioides) fillets subjected to a high-pressure (HP) treatment at 375 MPa for 20 min followed by refrigerated storage for 30 days. The optimum pressure/time was selected based on the complete inactivation of Listeria monocytogenes. Treated samples were analyzed by amino acid profile, visual color, microstructure and texture profile analysis. Lysine and glycine were the predominating essential and non-essential amino acids in hammour fillets. The total amino acids did not change by the HP-treatment, whereas the free amino acids decreased markedly from 4.35 to 2.43 mmol/g. The color of fillets changed significantly with the pressurization and storage in particular, a* and b* values. Hardness, compressibility and adhesiveness increased after the HP-treatment. FTIR results indicated a shift in the amide II band after the HP-treatment and storage due to high-pressure assisted protein denaturation. A porous structure was identified in the HP-treated microstructure of the fillet. The results indicated that HP-treatment could be successfully applied to hammour fillets for reduction of microbial growth with minor changes in quality.
This study aimed to understand the effects of high-pressure processing (HPP) on the physicochemical quality, protein degradation and endogenous enzyme activities of shrimp (Penaeus monodon) stored in ice for 28-day storage. Headed shrimps were vacuum-packed and subjected to HPP (100, 300, and 500 MPa at 15 ± 1 °C for 5 min). Results showed that HPP delayed microbial growth and reduced TVB-N values of shrimps as pressure increased. HPP did not completely inhibit proteases activity, and excessive pressure promoted myofibrillar proteins denatured, which were unstable during chilled storage. Water-holding capacity and protein solubility were diminished with HPP. However, the mechanical properties were stable in 500 MPa-treated samples during chilled storage prevented by changes in the water phase state and distribution.
This study investigated the effects of brine injection and high hydrostatic pressure (HHP) on the quality characteristics of pork loin. Brine with ionic strength conditions (0.7% vs 1.5% NaCl, w/v) were injected into pork loins, and the meat was pressurized up to 500 MPa for 3 min. As a quality indicator, moisture content, color, cooking loss and texture profile analysis (TPA) of pork loins were estimated. Based on the results, brine with low ionic strength (0.7% NaCl) resulted in low injection efficiency and high cooking loss, although, it improved tenderness of pork loin at moderate pressure level (~200 MPa). While high ionic strength condition (1.5% NaCl injection) lowered the hardness of pork loins at relatively high HHP level (400-500 MPa), it also caused high cooking loss. To commercialize the brine injected pork loins, it was necessary to regulate brine compositions, which was not evaluated in this study. Nevertheless, the present study demonstrated that brine injection followed by moderate pressure (200 MPa) could improve the tenderness of pork loins without causing other major quality losses.
The current study investigated the effects of high pressure (HP) treatment at 200 MPa and 500 MPa on quality characteristics of post-rigor tan mutton stored for 7 days at 4 °C, and textural changes were monitored during storage by means of the stress relaxation test. Application of 500 MPa high pressure significantly increased the elasticity and stiffness of meat after 7 days of storage ( P < 0.05), accompanied by a lighter and less red appearance and markedly enhanced centrifugal loss during storage campared to untreated ( P < 0.05). High pressure treatment at 200 MPa also substantially increased the lightness of samples throughout storage ( P < 0.05), and showed a significant increase in stiffness at the end of storage ( P < 0.05). Immunoblotting and electrophoresis (SDS-PAGE) analysis of key structural proteins revealed that myosin heavy chain denaturation began at 200 MPa, while actin denaturation occurred at 500 MPa. Troponin-T was continuously degraded in different treatments as storage progressed, and 200 MPa treatment and untreated represented similar degradation patterns, while 500 MPa treatment displayed more intense intact troponin-T at 38 kDa degradation. Results suggest that HP induced changes in cytoskeleton proteins, thereby affecting texture, water holding properties and lightness.
The central kitchen model has promoted the industrialization of the catering industry. The quality of central kitchen products is related to processing technology. The new non-thermal technology and heating technology not only have advantages over traditional technologies in improving product quality and safety, but also have more precise control over the processing process and a higher degree of automation. Using non-thermal technology conditioning before cooking can change the properties of food ingredients, and improve the quality and safety of cooked food. The new heating technology replaces the traditional heating method to provide thermal energy for food cooking, and has the advantages of shortening cooking time, improving quality attributes, improving processing efficiency and product safety. This article reviews the application and research progress of non-heating and heating technologies in fresh food processing in the central kitchen.
This study assessed effects of high pressure processing on physicochemical quality and endogenous enzyme activities of grass carp fillets stored at 4 ºC for 21-day storage. Fresh fillets were vacuum-packed and subjected to high pressure processing (0.1, 200, 300, 400, 500, and 600 MPa at room temperature for 15 min). Results showed that high pressure processing significantly delayed microbial growth, and reduced total volatile basic nitrogen (TVB-N) and thiobarbituric acid reactive substances (TBARS) levels of grass carp fillets, especially for the 600 MPa group. On the 21st day, the corresponding increases of 6%, 35%, 45%, 43%, and 53% in hardness were observed for 200 MPa, 300 MPa, 400 MPa, 500 MPa, and 600 MPa samples compared with control samples, respectively. In addition, enzyme activities in different groups decreased during storage. Among them, calpain, and myofibril-bound serine proteinases (MBSP) activities were immediately reduced after high pressure treatments, while the activities of collagenase, cathepsin B, and cathepsin D were significantly (P < 0.05) inhibited when the pressure exceeded 400 MPa. However, the pressure treatments activated cathepsin L initially, and then the activity gradually decreased in treated samples. Generally, high pressure processing reduced activities of most of the endogenous enzymes and improved the quality and extended the shelf life by at least 4 ~ 6 days of refrigerated grass carp fillets.
Abalone is one of the most valuable seafood products and the quality of ready-to-eat abalone products could be improved through tenderization treatments prior to a fully cooking process. In this study, a tenderization process (80 °C for 2 h) was applied to improve the quality properties of baked abalone muscle for the developing of ready-to-eat products. The quality properties of baked abalone (150–210 °C, 10–30 min) with and without pre-tenderization treatment prior to baking were evaluated through sensory evaluation, textural analysis and Hunter Lab colorimeter. In addition, amounts of sugars and α-dicarbonyl compounds in these products were determined via HPLC analyses. The baking condition at 180 °C for 20 min combined with pre-tenderization resulted in an optimal product. The baked abalone with pre-tenderization had better textural properties (hardness, 1031.12 ± 101.67; springiness, 0.96 ± 0.02; chewiness, 817.13 ± 113.43; shear, 2843.92 ± 35.67), sensory scores (30.1 ± 2.9) and color (25.28 ± 1.21) as compared to the baked abalone without pre-tenderization (hardness, 1990.91 ± 252.35; springiness, 0.87 ± 0.01; chewiness, 1164.43 ± 195.64; shear, 3910.79 ± 302.12; sensory score, 17.4 ± 1.0; color, 15.91 ± 0.74). The reducing sugar analysis indicated the presence of ribose and glucose in the baked abalone. In addition, the formation of α-dicarbonyl compounds (degraded from reducing sugars) including glucosone, 3-deoxyglucosone, glyoxal, methylglyoxal, and diacetyl were significantly promoted by the tenderization process in the baked abalone muscle. And the tenderization treatment led to an average of 218% increase in α-dicarbonyl compounds in the baked abalone muscle. The promotion of the formation of α-dicarbonyl compounds by the tenderization treatment contributed to the accumulation of pigments in the final baked products and led to desirable color.
Background
High pressure (HP) is an effective technology in food preservation. However, in fish, changes in appearance, texture, and chemical composition of the meat can be observed in more severe conditions. Although there are proposed mechanisms to achieve these events, there is no consistency of information to conclude on all of them.
Scope and approach
After a brief overview of HP technology, their main impact of fish meat quality were reviewed considering the targeted constituents and underlying mechanisms.
Key findings and conclusions
The main changes occurred between 200 and 300 MPa leading to a partial or total denaturation of proteins. In turn, these modifications were related to the increase of pH, hardness, whitening, decrease in water holding capacity, initiation of lipids, and proteins oxidation. The proposed mechanisms for these effects are very similar, suggesting the interrelationship between them. Lipid oxidation, protein oxidation, and discoloration are enhanced by iron content of the tissues (heme or free) and, possibly, with synergic phenomena. However, there is no consistency of information on the effects of these changes on consumers' opinion. Additionally, the intensity of the changes varies according to type of fish. Research is needed to determine clearly the reaction mechanisms, evaluate the effects of these changes concerning consumers’ opinion, and propose devices or strategies to minimize these changes when necessary.
This study investigated the moisture sorption isotherm (MSI) profiles of freeze-dried (FD) and boiled-dried (BD) abalone at 15°C, 25°C, and 35°C, and compared the quality characteristics of the abalone after rehydration. The equilibrium moisture content (EMC) and the calculated monolayer moisture content of FD abalone were higher than those of BD abalone. After rehydration, FD abalone showed a higher yield and a lower shear force than BD abalone. Additionally, the appearance of FD abalone was similar to that of fresh abalone, reflecting a potential application of FD to produce value-added dried abalone.
Citric acid pretreatment (2% and 4% citric acid) and high pressure processing (200-400 MPa for 3 min) were conducted to elucidate quality characteristics and shelf life of abalone during chilled storage. Physicochemical properties, total volatile basic nitrogen (TVB-N), and total viable count (TVC) were used as indicators of quality and the shelf life of abalone. Citric acid pretreatment caused a decrease in pH and lightness, and 4% citric acid pretreatment exhibited a positive effect on TVB-N and TVC. Pressurization suppressed the formation of TVB-N and the growth of TVC in abalone. However, excessive modification in physicochemical properties of abalone resulted from processing at a pressure higher than 300 MPa. To achieve microbial inactivation without severe modification in abalone quality, citric acid pretreatment with high pressure processing offered a potential advantage in maintaining characteristics of chilled abalone during prolonged storage period.
High-pressure processing (HPP) is used to increase meat safety and shelf-life, with conflicting quality effects depending on rigor status during HPP. In the seafood industry, HPP is used to shuck and pasteurize oysters, but its use on abalones has only been minimally evaluated and the effect of rigor status during HPP on abalone quality has not been reported. Farm-raised abalones (Haliotis rufescens) were divided into 12 HPP treatments and 1 unprocessed control treatment. Treatments were processed pre-rigor or post-rigor at 2 pressures (100 and 300 MPa) and 3 processing times (1, 3, and 5 min). The control was analyzed post-rigor. Uniform plugs were cut from adductor and foot meat for texture profile analysis, shear force, and color analysis. Subsamples were used for scanning electron microscopy of muscle ultrastructure. Texture profile analysis revealed that post-rigor processed abalone was significantly (P < 0.05) less firm and chewy than pre-rigor processed irrespective of muscle type, processing time, or pressure. L values increased with pressure to 68.9 at 300 MPa for pre-rigor processed foot, 73.8 for post-rigor processed foot, 90.9 for pre-rigor processed adductor, and 89.0 for post-rigor processed adductor. Scanning electron microscopy images showed fraying of collagen fibers in processed adductor, but did not show pressure-induced compaction of the foot myofibrils. Post-rigor processed abalone meat was more tender than pre-rigor processed meat, and post-rigor processed foot meat was lighter in color than pre-rigor processed foot meat, suggesting that waiting for rigor to resolve prior to processing abalones may improve consumer perceptions of quality and market value.
This study was carried out to evaluate the effect of high hydrostatic pressure on quality changes (microstructure, colour, texture and biochemical) of red abalone (Haliotis rufecens) during storage time at 4°C. High hydrostatic pressure (HHP) treatments were applied at 500MPa for 8min and 550MPa for 3 and 5min. Biochemical indices covering pH, total volatile basic nitrogen (TVB-N) and trimethylamine (TMA), as well as instrumental texture, microstructure and colour of abalone samples were determined immediately after treatment and throughout subsequent storage at 4°C. Results have shown that HHP-treated abalones have significantly (p≤0.05) higher pH, moisture and ash content than untreated abalones. Protein and fat contents of treated abalones were significantly (p≤0.05) lower compared to untreated sample (control). TVB-N and TMA levels for HHP-treated abalones rose over the storage period but did not exceed 28mg TVB-N/100g and 3mg TMA/100g, respectively at the end of 60days. Instead, the untreated sample exceeded the allowed limit in a 30day period for the TVB-N and TMA. However, all HHP treatments had less negative effects on tissue colour of abalone than untreated samples in the cold storage time; moreover, whiteness index was reduced to 8% at the end of day 60. A more compact structure was identified as high hydrostatic pressure was higher. Thus, it was concluded that holes in muscle fibres were often due to protein gelation, whenever pressure and protein concentration are high enough, confirming that the structure of abalone muscle treated with high hydrostatic pressure differed significantly from that of raw abalone meat.
To develop an optimal composite recipe for a functional abalone porridge including abalone viscera, this study investigated the effects of added viscera on the physical, textural and sensory characteristics of the porridge. Several kinds of abalone porridge were prepared with 1%, 2%, 3%, 4%, or 5% of the viscera (w/w) and with round rice, half rice, or ground rice. pH of the porridge with half and ground rice decreased with increasing amounts of the viscera. TBARS value increased with increasing size of rice and increased with increasing amount of the viscera in the porridge with round and ground rice. Yellowness of the porridge increased significantly by the addition of the viscra. Among the four textural properties, consistency and firmness increased with increasing size of rice; in contrast, viscosity and cohesivness decreased with increasing size of rice. However, textural properties of the porridge were not significantly different by the addition of the viscera. In the sensory evaluation, sensory scores of the porridge with round and half rice were higher than with round rice for texture, taste and total. In conclusion, concerning overall sensory evaluation, round rice porridge with 2% viscera, half rice porridge with 3% viscera and ground rice porridge with 4% viscera showed the best results, implying that developing functional abalone porridge using the viscera may be worthy.
The 2-thiobarbituric acid (TBA) test for the measurement of lipid oxidation was discovered over 40 years ago. Since then it has been widely used for the measurement of the oxidative state of biological and food materials. Despite copious literature references and its widespread usage there are still uncertainties over the exact chemistry of the reaction and its applicability. This review attempts to draw together the relevant publications and discuss the merits of the TBA test, particularly in the analysis of foods.
The oil in mackerel viscera was extracted by supercritical carbon dioxide (SCO2) at a semi-batch flow extraction process and the fatty acids composition in the oil was identified. Also the off-flavors removal in mackerel viscera and the storage improvement of the oils were carried out. As results obtained, by increasing pressure and temperature, quantity was increased. The maximum yield of oils obtained from mackerel viscera by SCO, extraction was 118 mgg(-1) (base on dry weight of freeze-dried raw anchovy) at 50 degrees C, 350 bar And the extracted oil contained high concentration of EPA and DHA. Also it was found that the autoxidation of the oils using SCO2 extraction occurred very slowly compared to the oils by organic solvent extraction. The off-flavors in the powder after SCO2 extraction were significantly removed. Especially complete removal of the trimethylamine which influences a negative compound to the products showed. Also other significant off-flavors such as aldehydes, sulfur-containing compounds, ketones, acids or alcohols were removed by the extraction.
There has been a renewal of interest in the survival strategies employed by deep-sea, high-pressure-adapted (piezophilic) microorganisms as well as in the effects of high pressure on mesophilic, 1-atmosphere-pressure-adapted microorganisms. This is partly the result of a greater appreciation of the adaptations of microorganisms to life in extreme environments and partly the result of the development of new techniques for examining physiological and molecular processes as a function of pressure.
In this study, the effects of physical parameters (30-270 MPa of pressure, 3-57 min of time, and 1- of temperature) on pork quality were investigated. Response surface methodology was used in order to monitor and model the changes in pork quality under varied pressure conditions. As quality characteristics, shear force, water holding capacity (WHC) and the CIE color of pork were measured, and optimum pressure conditions were evaluated by statistical modeling. Pressure improved the WHC of pork at relatively low temperature (
To study the effect of freezing rate on the duality of frozen abalone(Haliotis gigantea, GMELIN) liquid nitrogen spray freezing, air blast freezing, semi-air blast freezing, and still air freezing were carried out. The rheological change, protein denaturation, and free water content of frozen and thawed abalone were examined at the period of 0, 1, 2, and 3 month during cold Storage at . The results are summarized as follows : 1. The onset and duration of rigor mortis of fresh abalone was faster and shorter as compared to that of fishes. 2. There was no difference in compression value and shear value between freezing methods but they varied with a slight decrease in storage period. 3. Gradual decrease in extractibility of salt soluble protein was observed in all samples except those frozen with liquid nitrogen. 4. The free water of the foot muscle remained constant during the storage while that of the adductor muscle tended to increase. 5. A significant correlation was observed among the changes of panel texture and free water (P< 0.01), protein denaturation (P
This study evaluated the effects of high-pressure treatment on microbial growth and production of off-flavor compounds in raw octopus during 16 days of refrigerated storage. Chopped raw octopus samples were treated at 150, 300, 450, and 600 MPa for 6 min using high-pressure laboratory food processing equipment. The number of psychrotrophic bacteria on day 16 was reduced by 0.1, 0.5, 1.3, and 2.8 CFU/g after pressure treatment at 150, 300, 450, and 600 MPa, respectively, as compared with control group. The amounts of trimethylamine (TMA) and dimethylamine (DMA) produced in the chopped raw octopus treated at 600 MPa was significantly reduced by 42.5% and 62.2%, respectively, as compared to the levels in the control. The production of biogenic amines (BAs) increased up to 1.82 mg/g in the control after 12 days of refrigerated storage, while the BA levels in the 450 MPa- and 600 MPa-treated octopus were 1.40 and 1.35 mg/g, respectively. Thus, high-pressure treatment effectively inhibited microbial growth and suppressed the formation of off-flavor compounds in raw octopus. High-pressure treatment is a promising alternative technology for extending the shelf life of raw octopus.
The present experiment was an attempt to improve the shelf-life of cold-smoked sardine (Sardina pilchardus) using, singly or in combination, high pressure (300MPa/20°C/15min) and gelatin-based functional edible films enriched by adding an extract of oregano (Origanum vulgare) or rosemary (Rosmarinus officinalis) or by adding chitosan. The uncoated muscle itself exhibited a certain level of antioxidant power (as measured by the FRAP method) ensuing from the deposition of phenols during smoking. Coating the muscle with the films enriched with the oregano or rosemary extracts increased the phenol content and the antioxidant power of the muscle, particularly when used in association with high pressure, due to migration of antioxidant substances from the film. The edible films with the added plant extracts lowered lipid oxidation levels (as measured by the peroxide and TBARS indices) and also, to a lesser extent, reduced microbial growth (total counts), whereas the gelatin–chitosan-based edible films lowered microbial counts (total counts, sulphide-reducing bacteria). Neither luminescent bacteria nor Enterobacteriaceae were detected in any of the batches. The combination of high pressure and edible films yielded the best results in terms of both preventing oxidation and inhibiting microbial growth.
Whole Pacific oysters (Crassostrea gigas) were processed using high-pressure processing (HPP) treatment from 207 to 310 MPa at 0, 1, and 2 min and stored at < 4 °C and evaluated over 27 d. The pH of HPP samples decreased slightly from 6.3 to 5.8 during storage while the control (hand-shucked oysters) dropped to pH 4.1. Moisture content of the controls decreased slightly while HPP samples increased slightly. Pressure treatment did not significantly inhibit lipase activity during the shelf-life study. HPP reduced initial microbial load by 2 to 3 logs and counts remained at a reduced level through the storage study. Descriptive evaluation showed that HPP-treated oysters received higher quality scores than controls during the storage trial.
In the present study, the effect of thermal and equivalent high pressure processes on structural (texture and microstructure) and health-related (total β-carotene concentration, β-carotene isomerisation and β-carotene bio-accessibility) properties of carrots was investigated. Both a mild and strong pasteurisation process and a sterilisation process were considered.Both for pasteurisation and sterilisation, the high pressure process resulted in a similar or improved (2.6–4.5 times higher) hardness of the carrots compared to the equivalent thermal process. In contrast to the thermally treated samples, almost no β-carotene isomerisation was observed for the high pressure processed samples. However, the effect of high pressure on β-carotene bio-accessibility was dependent on the intensity of the process. Going from mild pasteurisation, over strong pasteurisation to sterilisation, the β-carotene bio-accessibility of the high pressure treated samples changed from 1.2 times higher, over 1.2 times lower to 2.5 times lower than that of the thermally treated samples.
Changes in the physicochemical and microbiological quality of oysters HP-treated at 260, 400 or 600 MPa for 5 min and stored at 2 °C on ice for 31 days were investigated. Microbial counts after HP treatment showed that the bacterial load was initially reduced at all pressures to levels below the detection limit. HP-treated oysters showed significantly increased pH and lightness (P < 0.05) relative to untreated oysters; during storage, pH changed little in the pressurised oysters but decreased slightly in untreated oysters. Little changes in colour were observed during storage at 2 °C on ice, compared to untreated oysters, which showed increased b-values (stronger yellow colour). From tests of mechanical properties, HP-treated oysters showed significantly increased cutting strength (P < 0.05) with increasing treatment pressure compared to controls throughout storage. However, HP increased lipid oxidation, the rate of which was dependent on the pressure applied. This study confirmed that HP processing can inactivate microorganisms and delay microbial growth in chilled stored oysters, but also affects their quality attributes.
Cultured abalone are currently distributed in numerous international markets, and consequently the abalone aquaculture industry is rapidly becoming respected as a reliable year-round source of high-quality abalone products. Yet there is very little information available in the literature relating to the opportunities and market requirements for cultured abalone in the major world markets. The Abalone Farm, Inc. (AFI) has been marketing cultured abalone on a commercial basis since 1982 and is currently distributing cultured abalone products in the USA, Japan, Hong Kong, and Canada. AFI has effectively developed product concepts which are well suited to the advantages and limitations of intensive farming, while being carefully refined to fit specific high-margin market niches within these market areas. This paper details the product concepts and market niches that AFI has found to offer the greatest opportunity for long-term profitability, while providing the best opportunity for immediate acceptance of product from emerging abalone producers.
After treatment at pressures above 400 MPa, the oxidative stability of the lipids in cod (Gadus morhua) muscle were markedly decreased as measured by the thiobarbituric acid (TBA) number. This was thought to be due to the release of metal catalysts from complexes, since addition of EDTA effectively inhibited the increased rates of oxidation. As judged by differential scanning calorimetry and electrophoresis this effect did not appear to be related to denaturation of the major proteins in meat, since myosin was denatured at 100–200 MPa and actin and most of the sarcoplasmic proteins at 300 MPa. A few water soluble proteins survived pressures of 800 MPa including several of the proteases, but there was a marked decrease in activity of the neutral proteases (pH optima 6.6) above 200 MPa. In contrast to heat-treatment, pressure was shown to lead to the formation of structures that were stabilised, at least to some extent, by hydrogen bonds and texture profile analysis (TPA) showed that the structures produced by heat and pressure treatments had very different textures.
Washed muscle fibres and minced pork were subjected to high pressure treatment at 800 MPa for 20 min at 20 °C prior to storage at 4 °C. In both cases, high pressure treated samples oxidised more rapidly than the controls, as measured by 2-thiobarbituric (TBA) number. The rate of lipid oxidation of the high pressure treated samples was similar to that induced by heat (80 °C for 15 min). No significant increased rate of oxidation was observed in minced meat samples treated at 300 MPa but above this pressure the rate increased with intensity. Minced meat samples pressure treated in air had higher initial TBA numbers than those treated in nitrogen, but upon storage both oxidised more rapidly than untreated samples. Differential scanning calorimetry, reflectance spectrophotometry and electrophoresis showed that treatment above 300-400 MPa caused marked denaturation of the myofibrillar and sarcoplasmic proteins and conversion of reduced myoglobin/oxymyoglobin to the denatured ferric form. The possible role of these reactions in catalysing lipid oxidation is discussed.
The effects of high pressure (to 800 MPa) applied at different temperatures (20-70 °C) for 20 min on beef post-rigor longissimus dorsi texture were studied. Texture profile analysis showed that when heated at ambient pressure there was the expected increase in hardness with increasing temperature and when pressure was applied at room temperature there was again the expected increase in hardness with increasing pressure. Similar results to those found at ambient temperature were found when pressure was applied at 40 °C. However, at higher temperatures, 60 and 70 °C it was found that pressures of 200 MPa caused large and significant decreases in hardness. The results found for hardness were mirrored by those for gumminess and chewiness. To further understand the changes in texture observed, intact beef longissimus dorsi samples and extracted myofibrils were both subjected to differential scanning calorimetry after being subjected to the same pressure/temperature regimes. As expected collagen was reasonably inert to pressure and only at temperatures of 60-70 °C was it denatured/unfolded. However, myosin was relatively easily unfolded by both pressure and temperature and when pressure denatured a new and modified structure was formed of low thermal stability. Although this new structure had low thermal stability at ambient pressure it still formed in both the meat and myofibrils when pressure was applied at 60 °C. It seems unlikely that structurally induced changes can be a major cause of the significant loss of hardness observed when beef is treated at high temperature (60-70 °C) and 200 MPa and it is suggested that accelerated proteolysis under these conditions is the major cause.
Extensive investigations in the last decade have revealed the potential benefits of high pressure processing (100-800 MPa) for the preservation and modification of foods. Simultaneously, a few pressurised foods have become commercially available in Japan, Europe and the USA. In the present review, the basic principles underlying the effects of high pressure on food constituents and quality attributes are first presented. Recent data concerning the following specific effects of high pressure on muscle and meat products are then reported and discussed: changes in muscle enzymes and meat proteolysis; modifications in muscle ultrastructure; effects on myofibrillar proteins; meat texture and pressureassisted tenderisation processes; pressure-induced gelation and restructuring of minced meat; changes in myoglobin and meat colour; influence of pressure on lipid oxidation in muscle; high pressure-inactivation of pathogenic and spoilage micro-organisms in meat; combined high pressure-moderate temperature 'pasteurisation' of meat products.
There has been a renewal of interest in the survival strategies employed by deep-sea, high-pressure-adapted (piezophilic) microorganisms as well as in the effects of high pressure on mesophilic, 1-atmosphere-pressure-adapted microorganisms. This is partly the result of a greater appreciation of the adaptations of microorganisms to life in extreme environments and partly the result of the development of new techniques for examining physiological and molecular processes as a function of pressure.
Withering syndrome (WS) is a disease of wild and cultured abalone caused by a Rickettsiales-like prokaryote (WS-RLP). This study compared the pathologic changes that occur during the progression of WS in red abalone to those caused by environmental stresses consisting of elevated temperature and food limitation and determined the impact of these stressors on WS prevalence and intensity. Farmed red abalone were administered a feed-based oxytetracycline therapeutic treatment to assure WS-RLP-free status prior to initiation of the experiment. Groups were then held in each of eight combinations of exposed vs. unexposed to WS-RLP, elevated vs. ambient temperature, and high vs. low food supply, for 447 days. Mortality was associated with starvation and disease but not elevated temperature alone. Elevated temperature significantly affected WS-RLP transmission: only 1.7% of WS-RLP- exposed abalone held at ambient temperature (12.3 degrees C) became infected compared to at least 72% of those held at elevated temperature (18.7 degrees C). Among exposed abalone at elevated temperature, fed animals exhibited greater infection prevalence but not greater infection intensity or digestive gland changes than starved animals, suggesting that abalone acquire infections by ingesting contaminated food. Food, temperature, WS-RLP exposure, and most of their interactions had significant effects on body condition and foot atrophy. Immunohistochemical detection of cell proliferation and apoptosis revealed no differences between normal digestive gland and that infected with WS-RLP. Body mass shrinkage, foot atrophy, elevated mortality, and decreased foot and digestive gland glycogen were observed in both WS-affected and starved, unexposed abalone, with the WS-RLP-exposed, starved group held at elevated temperature faring worst. Among exposed and unexposed animals, food supply but not temperature affected body mass and growth. These data demonstrate that the high morbidity and mortality exhibited by WS-RLP-infected abalone is a consequence of disease and not direct thermal stress. Drug residue analysis indicated oxytetracycline concentrations of up to 600 ppm in the digestive gland at 38 days post-treatment, an unusual degree of tissue retention of this therapeutant.
High hydrostatic pressure constitutes an efficient physical tool to modify food biopolymers, such as proteins or starches. This review presents data on the effects of high hydrostatic pressure in combination with temperature on protein stability, enzymatic activity and starch gelatinization. Attention is given to the protein thermodynamics in response to combined pressure and temperature treatments specifically on the pressure-temperature-isokineticity phase diagrams of selected enzymes, prions and starches relevant in food processing and biotechnology.
Post harvest biochemical and microbial changes Seafood: resources, nutritional composition and preser-vation (pp Boca Raton Studies on freezing of abalone. (1) Effects of freezing rate on the quality of frozen abalone
- Z E Sikorski
- A Kolakowska
- J R Burt
Sikorski, Z. E., Kolakowska, A., & Burt, J. R. (1990). Post harvest biochemical and microbial changes. In Z. E. Sokorski (Ed.), Seafood: resources, nutritional composition and preser-vation (pp. 55–75). Boca Raton: CRC Press Inc. Song, D. J. (1973). Studies on freezing of abalone. (1) Effects of freezing rate on the quality of frozen abalone. Bulletin of the Korean Fisheries Society, 6, 101–111 (in Korean, ab-stract in English).