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Citations
... The mechanism of heat generation in MD was based on the repeated change in electromagnetic field polarity that resulted in the rotation of the dipole water molecules. The mobility of water molecules is the main reason for heat generation with microwaves since it causes friction (Verma et al., 2020). In the present work, salting pretreatment might have caused myofibrils to bind with water molecules (von Gersdorff et al., 2021), and reducing the mobility of water, thus preventing water molecules from rotating in an electromagnetic field with MD. ...
Beef cuts were dried by tray drying (TD), microwave drying (MD), and TD+MD. Salting as pre-treatment was carried out with NaCl or NaCl+KCl salts to evaluate the effect of sodium reduction. The beef was divided into nine groups: three were subjected to TD, MD, and TD+MD; for the other six groups, dry salting was applied with 100% NaCl or 50% NaCl + 50% KCl, followed by MD, TD, or TD+MD. Processing times of TD, MD, and TD+MD were about 660, 250, and 300 min, and effective diffusivities (Deff) were 1.33 × 10-8, 3.88 × 10-8, and 3.57 × 10-8 m2/s, respectively. Compared with TD, the MD procedure resulted in significantly harder texture and lower rehydration ratio (p < 0.05). SEM images of dried beef indicated fractures and disruption after TD, while a compact structure was obtained with MD. Both salt types contributed a softer texture in rehydrated MD, but KCl did not change the hardness values of dried meat. MD could have great potential for drying meat by reducing drying time, and KCl could be applied as a substitute for NaCl without adversely affecting the structural quality.
... However, chemical fumigation is the most practiced strategy till date because of its minimal price, quick processing time, and simplicity of usage. After the Montreal Protocol, the use of chemical insecticides was limited, and alternative techniques such as modulation of temperature, use of botanicals and medicinal extracts, and dielectric heating are getting importance (Verma et al. 2019;Tiwari et al. 2021). Dielectric heating using microwaves is an effective and efficient method of disinfestation and has the potential to replace chemical fumigation (Yadav et al. 2014;Hajam and Kumar 2022). ...
... The heating mechanism depends largely on the moisture content of the biomaterials with dielectric properties, which determine the electromagnetic energy coupling and distribution. Heat is transferred from inside to outside during microwave heating in contrast to outside to inside in conventional heating (Verma et al. 2019). Thus, microwaves may be effective for insect control as insects contain relatively higher water compared to grains, therefore insects can be heated at a faster rate than grains (El-Naggar and Mikhaiel 2011). ...
Pulse beetle (Callasobruchus maculatus) is a common infestation during storage of legumes in India, and presently being managed by chemical fumigation. In the present investigation, a non-chemical method based on dielectric heating by microwaves (900 W, 2450 MHz) was studied for disinfestation of green gram at different grain layer thickness (5, 10, 15 and 20 mm) and exposure durations (0–60 s). The susceptibility (LT95) of different stages was in the order of egg (31.668 s) > grub (40.388 s) > pupa (44.176 s) > adult (49.018 s). The adult was tolerant up to 50 s (R2-0.799, P < 0.01) to microwave exposure duration without green gram, and up to 30 s (R2-0.804, P < 0.01) with green gram. Hundred percent mortality was observed at 10 mm (30 s, R2-0.969, P < 0.01) and 15 mm (30 s, R2-0.972, P < 0.01) grain layer thickness without significantly affecting grain quality. Cooking time and germination did not vary significantly up to 30 s of exposure, thereafter, reduced significantly. However, water uptake did not vary significantly up to 60 s of exposure. The microwave radiations are found effective for disinfestations of green gram without significantly affecting the grain quality.
... Traditional thermal pasteurization techniques for food preservation transfer of heat from a processing media to the product's slowest heating zone, which is then chilled. As a result, while thermal methods are effective mechanisms for the inactivation of microorganisms, they can occasionally induce changes in product quality such as off-flavor production, textural softening, and color and vitamin degradation (Soto-Reyes et al., 2022;Verma et al., 2020). Heat is generated in these technologies by the use of fuel or heaters and then transferred to food. ...
... As a result, because it requires energy consumption, this alternative is not environmentally beneficial. Furthermore, it is widely recognized that thermal processing necessitates water treatment, making it an expensive technology (Chiozzi, et al., 2022;Verma et al., 2020). ...
As a result of the growing demand for appetising, healthier food with longer shelf lives, food treatment technologies are constantly improving. e purpose of this review is to highlight the advantages and disadvantages of some of the most commonly used industrial techniques for microorganism deactivation and food processing, categorising them as those relying on high temperatures (ohmic heating, radio frequency heating, microwave heating, and infrared heating) and those relying on inherent chemical-physical principles (ultraviolet radiation, ozonation, high hydrostatic pressure, ultrasound, and membrane technology). Traditional thermal procedures can reduce the number of pathogenic bacteria to acceptable levels, but non-thermal technology can reduce or eliminate the negative effects of high temperatures. Recent advances in food treatment include the use of ultrasound to inactivate bacteria. roughout the text, new discoveries from the last decade are discussed, and non-thermal approaches have been shown to be more appealing for processing a wide range of foods. e primary goals of conscientious producers are to preserve the product's quality and nutritional qualities while also minimising bacteria and extending shelf life, and non-thermal technologies are making this treatment more feasible.
... The analysis of the thermal images, shown in the Figure 6, shows that the products are not uniformly heated due to their different porosity, density, and humidity. The microwave heating of products is largely dependent on the amount of water present in the product [8,23], which was also found in experimental research. Microwave heating is volume heating, and the temperature measurement of the heated product was carried out by using a contact thermometer which was inserted into the volume of the product as shown in Figure 7 (right). ...
... The analysis of the thermal images, shown in Figure 6, shows that the products are not uniformly heated due to their different porosity, density, and humidity. The microwave heating of products is largely dependent on the amount of water present in the product [8,23], which was also found in experimental research. Microwave heating is volume heating, and the temperature measurement of the heated product was carried out by using a contact thermometer which was inserted into the volume of the product as shown in Figure 7 (right). ...
This article presents novel research on the utilization of a neural-network-based time control system for microwave oven heating of food items within a solar-powered vending machine. The research aims to explore the control of heating time for various food products, considering multiple variables. The neural network controller is calibrated through extensive experimentation, allowing it to accurately predict optimal heating times based on input parameters such as food type, weight, initial temperature, water content, and desired doneness level. The results demonstrate that the neural-network-controlled microwave oven achieves precise and desirable heating durations, mitigating the risk of overheating and ensuring superior food quality and taste. Moreover, the solar-powered vending machine showcases a commitment to sustainable energy sources, effectively reducing dependence on non-renewable energy and minimizing greenhouse gas emissions. To maintain food quality and freshness, a food refrigeration unit is integrated into the vending machine, employing load-balancing technology to control the refrigeration chamber’s temperature effectively. Energy efficiency is prioritized in both the refrigeration unit and the microwave oven through intelligent algorithms and system optimization. The combination of a neural-network-controlled microwave oven, a solar-powered vending machine, and a food refrigeration unit introduces a novel and sustainable approach to food preparation and energy management.
... To recover phenolic and other bioactive compounds from the various parts of the C. papaya plant, extraction techniques like soxhlet extraction, ultrasonication, enzyme-assisted extraction, and microwave-assisted extraction (MAE) are frequently used (Alara et al., 2021;Chávez-González et al., 2020;Tripathy et al., 2021Tripathy et al., , 2022Verma & Srivastav, 2020aWang et al., 2022). One of the many applications where the MAE method is regarded as the most efficient modern extraction technique is the extraction of phenolics as well as other kinds of compounds (Alara et al., 2021;Chávez-González et al., 2020;Mukhaimin et al., 2019;Vallejo-Castillo et al., 2020;Verma, Mahanti, et al., 2020;Wang et al., 2022). Moreover, response surface methodology (RSM) is an essential technique that is frequently employed for process parameter optimization. ...
The present research aims to establish its scientific basis by proposing and validating the hypothesis that
bioactive phytochemicals of Carica papaya can be an ideal functional food and drug compound for the management
of diabetes mellitus. The in silico molecular docking and pharmacokinetic analysis of phytochemicals of
C. papaya revealed that the phytochemicals have a high potential to inhibit α-amylase and α-glucosidase enzymes
( 9.3 to 7.7 kcal/mol), responsible for post-prandial high blood glucose level and low to moderate level of
absorption, distribution, metabolism and excretion (ADME) and toxicity. The experimental design was set up for
industrial application for high-yield recovery of bioactive components from C. papaya leaf. The microwaveassisted
extraction optimized response variables from 17 experimental runs, like total phenol content, total
flavonoid content, total tannin content, and antioxidant activities (1,1-diphenyl-2-picrylhydrazyl and ferricreducing
antioxidant power) were obtained at a temperature of 61 ◦C at a microwave power level of 807 W
and 45 min of processing. The phytochemical screening, thin-layer chromatography, Ultraviolet–visible spectroscopy,
Fourier transform infrared spectroscopy, and liquid chromatography-mass spectrometry spectral
analysis revealed the presence of 18 out of 21 reported major phytochemicals of C. papaya. The in vitro enzymatic
activity indicated high inhibition for α-amylase (IC50 40.03 ± 2.61 μg/mL) and α-glucosidase (IC50 66.52 ± 1.52
μg/mL) enzymes. The hemolytic activity was found to be less than 5% compatible with ISO standards for the
intervention of biomaterials. Furthermore, the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide
and chorioallantoic membrane assay assays suggested low toxicity at the concentration of up to 62.5 μg/mL. This
study will help food and pharmaceutical researchers, scientists, and industrialists produce antidiabetic food
compositions and medications to help diabetics manage their diabetes and enhance their health.
... Pasteurization is generally carried out under normal pressure because high pressure will make fresh noodles stick together into a mass and modify the organoleptic characteristics . After pasteurization immediately, the product must be cooled to 4 °C (Verma et al. 2020). Nevertheless, the thermal stress generally compromises the sensory characteristics of fresh pasta (Schettino et al. 2020). ...
... Thus, the use of microwaves to sterilize or pasteurize food has received increasing attention, and microwave technology has enjoyed a wider application. Microwaves with frequencies of 915 MHz and 2450 MHz are most used to kill pathogenic bacteria and the organisms responsible for food spoilage Verma et al. 2020). An increase in frequency leads to a decrease in the penetration depth, so 915 MHz microwaves have a deeper penetration depth than the 2450 MHz microwaves, therefore may provide more uniform heating (Verma et al. 2020). ...
... Microwaves with frequencies of 915 MHz and 2450 MHz are most used to kill pathogenic bacteria and the organisms responsible for food spoilage Verma et al. 2020). An increase in frequency leads to a decrease in the penetration depth, so 915 MHz microwaves have a deeper penetration depth than the 2450 MHz microwaves, therefore may provide more uniform heating (Verma et al. 2020). The mechanism for the inactivation of microorganisms by microwaves at sublethal temperatures includes both thermal and non-thermal effects, as penetrating microwaves cause deleterious biological effects in organisms after they have been subjected to a certain degree of radiation Chandrasekaran et al. 2013). ...
Gluten network plays different roles according to the bakery or pasta products that are produced. While it is the key element for obtaining bread and pasta, it is less crucial for obtaining cookies and sweet batter-based products, such as cakes and muffins. In this regard, obtaining the gluten-free (GF) counterparts of the former products is more challenging than for the latter. This chapter will address the use of the most common additives used both in the laboratory and the industry for the development of GF products. Non-starch polysaccharides, modified starches, proteins, enzymes, emulsifiers and antimicrobial agents are covered. Focus is on the most popular bakery products such as bread, cookies, cakes, muffins, and pasta. The main differences with the applications of these additives in wheat-based products are discussed. A nutritional perspective is also included.KeywordsPolysaccharidesHydrocolloidsAnimal proteinsPlant proteinsEnzymesEmulsifiersAntimicrobialsBreadSweet bakery productsPasta
... Pasteurization is generally carried out under normal pressure because high pressure will make fresh noodles stick together into a mass and modify the organoleptic characteristics . After pasteurization immediately, the product must be cooled to 4 °C (Verma et al. 2020). Nevertheless, the thermal stress generally compromises the sensory characteristics of fresh pasta (Schettino et al. 2020). ...
... Thus, the use of microwaves to sterilize or pasteurize food has received increasing attention, and microwave technology has enjoyed a wider application. Microwaves with frequencies of 915 MHz and 2450 MHz are most used to kill pathogenic bacteria and the organisms responsible for food spoilage Verma et al. 2020). An increase in frequency leads to a decrease in the penetration depth, so 915 MHz microwaves have a deeper penetration depth than the 2450 MHz microwaves, therefore may provide more uniform heating (Verma et al. 2020). ...
... Microwaves with frequencies of 915 MHz and 2450 MHz are most used to kill pathogenic bacteria and the organisms responsible for food spoilage Verma et al. 2020). An increase in frequency leads to a decrease in the penetration depth, so 915 MHz microwaves have a deeper penetration depth than the 2450 MHz microwaves, therefore may provide more uniform heating (Verma et al. 2020). The mechanism for the inactivation of microorganisms by microwaves at sublethal temperatures includes both thermal and non-thermal effects, as penetrating microwaves cause deleterious biological effects in organisms after they have been subjected to a certain degree of radiation Chandrasekaran et al. 2013). ...
The aim of the chapter is to introduce different options, traditional and non-traditional starch resources as alternatives to cereals that are adequate for gluten-free food development. In these products, starch is incorporated into the formulation to improve baking characteristics such as the specific volume, colour, and crumb structure and texture. As an introduction, physicochemical and structural characterisation, nutritional perspective and some applications of native or modified starches are described. Although, corn, rice, potato and cassava are the most popular and accessible gluten-free starches, many sources have been studied as alternatives. Sweet potato, lentil, sago, taro, nuts and Andean roots among others, are some of novel sources that have been described. The main physical and chemical characteristics, extraction methods and some recommendation about their use in food applications are provided.KeywordsPotato starchCassava starchNon-conventional starchesGranule structureModificationFunctional properties
... Microwave radiation covers the frequency range between 300 and 3000 MHz and recommended frequencies for scientific, medical and industrial applications are 915 (896 MHz is recommended in Europe) and 2450 MHz. Magnetrons are used to generate microwave radiation in the microwave driers [1,[69][70][71][72]. ...
Drying is an important process in the tea processing industry. Drying arrests enzymatic reactions to produce a stable product with increased shelf life. Development of the quality attributes such as taste, fragrance, color, etc. in tea is initiated during processing steps prior to drying, which undergoes the final stage of development during drying to produce the characteristic features of the final product as made tea. In this article, investigations on the drying of tea leaves using industrial/commercially successful driers, such as, endless chain pressure drier, fluidized bed drier and vibro-fluidized bed drier have been discussed. Additionally, investigations on the driers under research stage, such as microwave drier, superheated steam drier and radio frequency drier have also been explored.
Drying is an energy intensive process in the tea factory. It consumes 3.5–6 kWh of thermal energy per kg of made tea. Fossil fuels are primarily utilized in the tea factories to meet the thermal energy demand of drying. The specific carbon dioxide emission of tea factories is found in the range of 2.15 to 2.86 kg per kg of made tea. Several attempts have been made to develop the renewable energy based drying system to meet the energy requirements in the tea factories and to minimize the greenhouse emissions. This study also reports past works on renewable-energy-assisted tea drying. Apart from this, study proposes solar energy-based tea drying system along with thermal energy storage and/or integrated with fossil fuel-based furnace.
... The main heat transfer mechanisms in the conventional heating such as roasting and convective air drying are conduction and convection; and due to the low effective thermal conductivity of food products ( Carson, 2006 ), the time at which the center of food reaches the temperature of its surface during these thermal procedures is considerably high. Therefore, conventional methods cause prolonged exposure of food surface to the high-temperature heating source, leading to their quality deterioration and high energy consumption ( Jiao et al., 2018 ;Verma et al., 2020 ). ...
... This technology generates heat inside the material by the frictional ions movement and polar rotation of dielectric molecules as a result of exposure to microwave electromagnetic energy, with the usual household and industrial frequency of 2450 and 915 MHz, respectively. Thus, reducing food products' thermal processing using the microwave heating technique can preserve the product quality and make the process more environmentally friendly ( Heydari et al., 2022b ;Verma et al., 2020 ). Despite the higher drying rate of microwave heating than conventional methods, there are still options to enhance the drying rate through mass transfer modification. ...
... Moreover, a vacuum environment reduces food exposure to oxygen and prevents oxidation reactions in food materials. So, the final product is obtained with high preserved quality at boosted drying rate at a lower temperature ( Verma et al., 2020 ). ...
Adding lentil flours as an affordable and sustainable plant-based ingredient in food formulation plays vital role in promoting human health and reducing the environmental footprint of human diet. Also, the inclination toward sustainable food products requires the introduction of green technologies as the substitution of conventional heating. A proper substitution demands investigating the impact of different heat transfer mechanisms of conventional and green volumetric heating processes on starch gelatinization and enhancement in starch structural, functional, and nutritional properties. Hence, modified lentil flours through soaking/germination pretreatment followed by volumetric heating (microwave-infrared and vacuum-microwave drying) and conventional heating (roasting and convective air drying) were examined in this study. The results showed that using microwave-infrared not only significantly decreased processing time but also created a similar gelatinization degree compared to the lentils treated by roasting at 240°C. Vacuum-microwave also found a suitable substitution for convective air drying, producing similar modified starch at a shorter processing time. Almost all thermal treatments improved total starch digestibility; however, microwave-infrared drying and roasting increased rapidly digestible starch while vacuum-microwave and convective air drying enhanced slowly digestible starch. Generally, soaking/germination followed by the mentioned dryings leads to modified flours by changes in their starch structure, resulting in the effective utilization of pulse flours as a promoting food ingredient.
... Up to now, the commonly used methods to reduce microbial contamination of grains include heat treatment and chemical fumigation methods. The heat treatment of oat surface sterilization is simple to operate and with little pollution, as it includes methods such as steaming, stir-frying, far red roasting, microwaving, and so forth (Ekezie et al., 2017;Verma et al., 2020). However, as these methods are timeconsuming and need a lot of energy, they can negatively affect the quality and functional properties of grains and grain products . ...
Background and Objectives
Naked oat grain is easily contaminated by microorganisms, and it needs pretreatment to extend its shelf life. Low‐temperature plasma treatment (LTPT) has the advantages of less energy consumption, safety, and convenience, and its applications in grain include microbial inactivation and flour modification. Therefore, we studied the changes in oat microbes and the physicochemical properties of oats at different plasma treatment times (0, 5, 10, 15, and 20 min at an output discharge voltage of 60 kV).
Findings
The results demonstrated that LTPT significantly decreased the number of microorganisms with the increase in treatment time, especially at 20 min. LTPT increased the L * and b * values and decreased the a * value of oat flour. Proper treatment time (5–10 min) did not affect the germination rate of the grain. Compared to the control sample, LTPT increased the water‐binding capacity and swelling power of flour and decreased the peak viscosity, final viscosity, and setback value. However, LTPT did not change the crystal structure. Besides, by fitting the peak of the amide region in Fourier transfer infrared analysis, it was found that the β‐sheet and α‐helix increased after treatment for 5–10 min.
Conclusions
These results indicated that LTPT (20 min) can effectively reduce the microbial count of oats and proper time treatment (5–10 min) can regulate the function of the flour and improve its quality.
Significance and Novelty
LTPT as a new nonheat treatment technology can not only effectively reduce the microbial content of the grain but also improve the quality of the flour, which is a better pretreatment method for oat flour.
