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Advanced Retorting, Microwave Assisted Thermal Sterilization (MATS), and Pressure Assisted Thermal Sterilization (PATS) to Process Meat Products
... The long exposure time causes severe thermal degradation of food quality, particularly near the food surface. The loss of food quality, including vitamins, color, protein, lipids, and texture, due to conventional thermal processing has been summarized by Barbosa-Cánovas et al. [26], Lucci et al. [27], and Peng et al. [1]. ...
... In the WSU MATS system, a microwave-transparent conveyor belt with pockets made of a low loss tangent polymer material (Polytetrafluoroethylene, PTFE) is used to transport food trays or pouches through the MATS processing. The food packages are placed in the pockets as they move through different sections in MATS [26]. To enhance the transport capability of carriers for food packages of various sizes and shapes, an improved metal transport carrier (Tang Cage™) has been designed for MAPS (Fig. 13.5) [55,56]. ...
... The Federal Regulations (21 CFR 108) require commercial processors to register their establishments and file scheduled processes with the FDA for each specific product, product style, container size and type, and processing method. The pilot-scale MATS system at WSU played an important role in obtaining FDA and USDA FSIS (Food Safety and Inspection Service) acceptances [26]. The system went through rigorous temperature distribution and heat penetration testing before being used in validation for several food products. ...
Thermal sterilization and pasteurization are important processes in the food industry for the production of microbiologically safe foods with extended shelf life. Conventional thermal processing operations use saturated steam from coal or natural gas boilers to inactivate pathogenic and spoilage bacteria. These operations for packaged foods have severe limitations, such as lengthy processing times, low energy efficiency, poor food quality, and high carbon emissions due to the reliance on fossil fuels. Microwave-assisted thermal sterilization and pasteurization hold the potential to overcome some of those limitations. Microwave heating provides fast, volumetric, and energy-efficient heating, and can be directly powered by renewable electric sources (such as solar, wind, and hydro power). This chapter provides an overview of the principles and requirements of thermal processing, emphasizing their importance in achieving food safety and shelf stability. Furthermore, it presents recent advancements in 915 MHz single-mode microwave-assisted thermal sterilization (MATS) system and the microwave-assisted pasteurization system (MAPS), which have gained FDA acceptance and a non-objection letter from USDA FSIS. Finally, the chapter discusses the future potential of using solid-state microwave technology in improving the design of microwave heating systems.
... 18,19 Longer processing time at high temperature (70-90°C for pasteurization and 121°C for sterilization) signicantly deteriorates the quality of food including loss in color, nutrients (vitamins, ascorbic acids, and chlorophyll), aroma and texture. 8,20 This is due to conduction and convection heating (outside-to-inside) of packaged food. Slow heat transfer from the heating medium to the cold spot frequently leads to overprocessing (i.e., treating the material at the container's edge more severely than is necessary to ensure commercial sterility). 1 Creating agitation is an alternative way to improve traditional retorting which is applicable to certain groups of containers, like cans. ...
... This method works well for foods that include liquids or semi-liquids since convection heating accelerates the heating process. 3,20 The product's viscosity, headspace, container geometry, arrangement of containers inside the chamber, and the type of retort motion all inuence the convection process. 20 Agitation-based retorts are available, including end-over-end processing, hydrostatic cookers, and continuous and semi-continuous agitating retorts. ...
... 3,20 The product's viscosity, headspace, container geometry, arrangement of containers inside the chamber, and the type of retort motion all inuence the convection process. 20 Agitation-based retorts are available, including end-over-end processing, hydrostatic cookers, and continuous and semi-continuous agitating retorts. 3,20 They are severely criticized since there are few opportunities for thermal processing optimization and they are only utilized for a restricted variety of containers, most of which have some symmetry, such cans and jars. ...
Thermal processing is an important unit operation in the food industry for the production of prepackaged foods with extended shelf-life. Conventional thermal processes, such as canning, are widely employed in the food industry, but the energy efficiency of these processes is typically low. In addition, a significant amount of water is wasted during these processes. In recent years, advanced microwave-based pasteurization and sterilization systems have been developed for the production of extended shelf-life products at refrigeration and room temperatures, respectively. Microwave systems are relatively more water and energy efficient, can be directly powered by renewable electricity sources (e.g., solar, wind, or hydropower), and have potential to reduce greenhouse gas emissions, and thus environmentally sustainable. The quality of microwave processed foods is often superior to that of foods processed using conventional thermal methods. Glass, metal, paper, and synthetic polymers continue to dominate as packaging materials for thermally processed food. However, sustainable packaging materials are being developed and investigated for thermally processed foods.
... However, this technology is inefficient in inactivation of bacterial spores and some enzymes (Silva and Evelyn, 2020). Thus, a combination of HPP and thermal energy (high-pressure thermal processingdHPTP) has been investigated for some 20 years to obtain safe foods of higher quality when compared to foods processed by conventional thermal treatments ( Barbosa-C anovas et al., 2014). In this process, foods have a shorter retention time at moderate or high temperature and high pressure versus conventional pasteurization or sterilization. ...
... The most common typical processing settings of pressure, temperature, and retention time found in the literature are 400e600 MPa, 60e130 C, 1e10 min, respectively Casulli et al., 2017). Depending on product characteristics, these conditions can be used to obtain commercial sterilization of shelf-stable lowacid foods ( Barbosa-C anovas et al., 2014;Dankal et al., 2020). ...
... Continuous heating promotes oxidation in pork slices and lipid oxidation and hydrolysis in the edible oil of the soup, leading to off-flavor generation and the loss of sensory quality [36,37]. The panelists preferred the odor and soup taste of RFSW-sterilized samples compared with the CON-SW group, which might be due to the lower level of TBARS (Section 3.4.3) in meat sterilized by RFSW-170. ...
... The scores of each item under RFSW at three temperatures showed no significant differences (p > 0.05), indicating that the panelists could hardly tell the distinction among PSPSs. Continuous heating promotes oxidation in pork slices and lipid oxidation and hydrolysis in the edible oil of the soup, leading to off-flavor generation and the loss of sensory quality [36,37]. The panelists preferred the odor and soup taste of RFSW-sterilized samples compared with the CON-SW group, which might be due to the lower level of TBARS (Section 3.4.3) in meat sterilized by RFSW-170. ...
In this study, a new device was used to inactivate G. stearothermophilus spores in ready-to-eat (RTE) poached spicy pork slices (PSPS) applying radio frequency (RF) energy (27.12 MHz, 6 kW) and superheated water (SW) simultaneously. The cold spot in the PSPS sample was determined. The effects of electrode gap and SW temperature on heating rate, spore inactivation, physiochemical properties (water loss, texture, and oxidation), sensory properties, and SEM of samples were investigated. The cold spot lies in the geometric center of the soup. The heating rate increased with increasing electrode gap and hit a peak under 190 mm. Radio frequency combined superheated water (RFSW) sterilization greatly decreased the come-up time (CUT) compared with SW sterilization, and a 5 log reduction in G. stearothermophilus spores was achieved. RFSW sterilization under 170 mm electrode gap reduced the water loss, thermal damage of texture, oxidation, and tissues and cells of the sample, and kept a better sensory evaluation. RFSW sterilization has great potential in solid or semisolid food processing engineering.
... The meat samples must be sterilized at 121°C prior to measurement, a process that is crucial for killing pathogenic microorganisms and ensuring the analysis is suitable for halal certification. 13 While this high temperature is effective for sterilization, it may also affect the food's properties. Additionally, although the technique can effectively distinguish pork from chicken and beef based on dielectric peaks, the exact biomarkers responsible for these differences remain unknown. ...
Food authenticity is crucial for ensuring consumer trust, public health and market integrity with particular importance in the context of religious and cultural practices. For the global Muslim population, halal food adherence is not merely a dietary preference but a fundamental aspect of faith, necessitating rigorous verification of halal status. Traditional methods of halal food authentication such as sensory evaluation basic chemical analysis, electrophoresis and ionizing radiation often fall short in addressing the complexities of modern food production and supply chains leading to potential cross‐contamination and mislabeling. These limitations underscore the urgent need for advanced techniques in halal food authentication. This paper explores technologies such as DNA‐based methods, spectroscopy, chromatography, immunological assays, and emerging innovations like blockchain and artificial intelligence. By providing a comprehensive overview of these advanced techniques, this paper aims to highlight their potential in enhancing the accuracy, reliability and efficiency of halal food authentication thereby supporting industry stakeholders, regulators and consumers in upholding halal integrity.
... The cooking process is crucial because it affects technological properties, which depend on the cooking method, destroys microorganisms, and makes these meat products safer to eat. Although cooking meat is an ancient practice, it has evolved into refined daily cooking practices as well as sophisticated modern thermal processing units with multiple process controls [1,2]. It produces structural changes that contribute to the development of specific sensory properties (texture, flavor, and color), rendering products more palatable and appetizing for consumers [3], and composition changes such as nutrient loss and the balance of healthy and unhealthy compounds [3][4][5]. ...
This study analyzed the effect of different cooking practices on the physicochemical (cooking loss, pH, proximate composition, mineral content, color, and texture) and sensory characteristics of cooked longanizas. Four cooking methods were tested: an air fryer oven (AF; 15 min at 180°C), a convection air mode oven (HD; 15 min at 180°C), a combi-steam mode oven (HW; 15 min at 180°C), and a saturated steam mode oven (HS; 45 min at 90°C). The cooking loss and pH were significantly higher in HS longanizas. The cooking process affects the composition differently. The HS treatment resulted in the lowest (p<0.05) moisture and the highest (p<0.05) fat content, while the AF treatment showed significant sodium content. Cooking methods significantly increased L∗ values, with HD showing the highest (p<0.05) among the cooked treatments. HS longanizas exhibited the lowest (p<0.05) Kramer shear force (KSF), likely related to the prolonged cooking time. Regarding sensory aspects, no differences were found among the samples.
... The second main method of sterilization uses oscillating electric fields to heat up the food's ions, which prevents germs from regularly metabolizing, growing, and reproducing. Microwave sterilization produces results similar to those of high-temperature sterilization [4,63]. ...
Microwave processing, one of the most widely used methods of food preservation and processing, employs electromagnetic radiation to heat food swiftly and effectively. Microwaves are frequently used in the food processing industry for drying, tempering, sterilization, baking, etc. Microwave-assisted food processing has the benefit of using less energy due to volumetric heating, lowering processing times and costs, and preserving the food’s nutritional value. The uneven moisture distribution during drying operations and non-uniform temperature distribution, which cause chemical changes that influence the flavor of the food and result in inconsistent flavor and texture, are two key drawbacks that prohibit it from being more commonly adopted commercially. A variety of elements, such as a heightened Maillard reaction, a drop in water content, and altered enzyme activity, can be held accountable for changes in flavors and texture. The effect of microwave processing on food flavor, however, is complex and can vary depending on the type of food being processed, the processing settings, and other factors. Microwave heating can occasionally enhance the flavor of some foods since it preserves their natural flavor and texture and reduces the loss of volatile compounds during processing.
... In this technique, the food products are exposed to 915 MHz frequency microwave energy with the purpose of reaching internal heating homogeneous. Dr. Juming Tang's Microwave Group at Washington State University developed this technology 17 . The food industry uses this type of stimulation for food preparation and conservation. ...
The purpose of this work was to review the recent advances in the non-thermal treatments for food preservation such as ultrasound, microwave, ultraviolet irradiation, electric field, electromagnetic field, and high hydrostatic pressure. In this review, the non-thermal treatments can generate in food minimal alterations of the physicochemical and mechanical properties, stimulate the production of edible microorganism, generate localized heating conserving its nutritional quality, promote the enzymatic inactivation, and have antimicrobial effects. Non-thermal treatments used for sterilization process in food can implement the use of others technologies such as example the nanostructured materials used in the fabrication of food packaging, the use of different types of food packaging i.e., active, intelligent, biodegradable, the application of treatments such as the use of nzyme or biopreservation, and the incorporation of bio-compounds.
... Nessas condições, o colágeno contrai-se intensamente, comprime as miofibrilas e provoca a expulsão da água, levando à desidratação da carne. Dependendo do grau de desidratação, a carne perde suculência(COMBES et al., 2004;BARBOSA-CÁNOVAS et al., 2014;SCUSSAT et al., 2017;TORNBERG, 2005). Sob temperaturas abaixo do intervalo de 60 °C a 65 °C, o grau de contração do colágeno é menor, com menores perdas de água pela carne e melhor conservação da suculência. ...
... Water is used in two parts: in the pre-heating section, hot water bath is used to pre-heat (around 50 °C) the food product and not to be cooked, and in the microwave sterilizing section water surrounding the food product gets heated along with the food product [68,53,69]. This MATS system is one of the most advanced and appealing industrially available equipment for microwave sterilization [70]. Its four sections: pre-heating, heating, holding, and cooling section are interconnected and arranged sequentially. ...
Microwave sterilization has seen many innovative solutions to solve its primary problem of non-uniform heating. Since its initial studies in the late 1940s, there were solutions that were put forward to address, such as using mechanical holders to contain the inner pressure of the package with food materials, use of fluids instead of mechanical holders, use of strong containers or polymeric packages, and use of monolayer and multilayer packaging. But even all these solutions could not entirely solve the problem of non-uniform heating. After the 2000s, the rise in numerous numerical simulations and modelling software, opened the doors to further explore this field of research with more details and to numerically model the multi-physics phenomenon. However, studies have still not been sufficient to commercially deploy microwave sterilization systems to their full potential. Challenges such as temperature measurement, pressure measurement and control, usage of the right packaging material, and homogeneous heat distribution are still to be addressed, all while developing an energy-efficient process using numerical modelling and simulation tools. Hence, this review aims to study the microwave sterilization systems since the early days of research and the packaging aspect during the microwave sterilization process. The review also explores the potential held by the numerical simulation and modelling tools in this field of microwave sterilization.
... Therefore, it is important to study the influencing factors of consumers' word-ofmouth generation of prepared dishes in the social network context to improve the awareness [8,9]. With the passage of time, the research direction is gradually shifting to the establishment of the risk model for preventing bacterial contamination of prepared dishes [10], detection of MSG addition in food products [11], nutritional quality assessment of prepared dishes [12], Sterilisation technologies for the treatment of prepared dishes [13], the development of functional products, such as low-sodium seasonings [14] and the impact of industrialised prepared dishes and traditional dishes on public consumption habits [15]. In recent years, foreign research has focused more and more on improving the quality of prepared dishes. ...
With the rapid development of China’s prepared vegetable product market, consumer demand for prepared vegetable products is increasing. The study adopts a qualitative research method to construct a model of factors influencing the generation of consumer word-of-mouth (IWOM) in the online consumption context, taking the real consumer word-of-mouth of Jingdong’s own flagship shop of prepared dishes as the object of the study. The model states that the objective factors that promote the generation of word of mouth include specific consumption context (emotionality, initiality, scarcity, convenience and process) and specific product attributes (richness, safety, accessibility and emotionality). Meanwhile subjective factors design consumer satisfaction with the product (satisfaction with a single attribute and satisfaction with the brand as a whole) and emotions (positive self-conscious emotions, high arousal positive emotions and medium arousal positive emotions). Objective factors may contribute directly to the generation of word-of-mouth, or they may further contribute to word-of-mouth generation through subjective consumer factors. In addition, IWOM is often generated not by a single factor, but by a combination of factors.
... Milk exhibits significantly increased luminosity, a* (less green), and b* (yellower) values with an increase in fat content (P < 0.05) (Amador-Espejo et al., 2021). Decreasing milkfat globule size (Barbosa-Cánovas et al., 2014;Bermúdez-Aguirre & Barbosa-Cánovas, 2008) and, to a lesser degree, whey protein particle size that creates a more homogenous sample with smaller particles that increase visible light scattering (Arzeni et al., 2012). Increase of WPC increased the redness (a*) and yellowness (b*) of the product (da Silva Teba et al., 2017). ...
Paneer, an indigenous dairy product, is used in many Indian recipes. It's popular since it's healthy. It contains plentiful high-quality protein, fat, vitamins, and minerals. The objective of this study was to develop a low-fat paneer (LFP) that is fortified with inulin, whey protein concentrate (WPC), and a combination of both (0.25 g/g inulin (S2), 0.30 g/g WPC (S3)), and their combination 0.27 g/g (S4) milk fat replaced respectively) and was compared with the control (S1, from 0.5% fat-containing milk). The skim milk (0.5% fat) was pre-heated to 45 • C and the Inulin, WPC, and their combination was added to the milk and then paneer was made. The inclusion of fat replacers significantly (p < 0.05) affected the sensory characteristics of LFP. S2 received higher acceptability, followed by S1, S3, and S4. Texture profile analysis (TPA) showed significant increases (p < 0.05) in hardness, cohesiveness, gumminess, and chewiness between S1 and S4, but no significant change (p > 0.05) in adhe-siveness and springiness. The lightness, redness, and yellowness values of S1, S2, S3, and S4 were 67.94 to 84.89, − 2.17 to-2.84, and 13.80 to 16.37 respectively. Physicochemical and microbiological quality of LFP were also assessed following storage at 7 ± 1 • C for 0, 3, 5, and 7 days. Significant (p < 0.05) changes in titrable acidity, thiobarbituric acid value, tyrosine, and free fatty acid (FFA) values have been observed in storage. After seven days of storage, all samples showed a decrease in water activity (p < 0.05), with S1 having a value of 0.987 and S2 0.981. During refrigerated storage (up to 7 days), standard plate count (SPC), coliform, yeast, and mold counts significantly differed (p < 0.05) across samples S4 had the greatest SPC (5.35 log cfu/g), coliform (66 cfu/g), yeast, and mold (72 cfu/g) on day 7. S2 was the most accepted storage quality for all treated samples, followed by S3 and S4. Results of the study revealed that an acceptable quality low-fat paneer can be manufactured by incorporating inulin and WPC. The results also suggest that low-fat paneer may help health-conscious consumers, especially those with cardiovascular issues.
... The negative aspect of these thermal approaches is that the treatment at a temperature over 100 °C can modify the temperature-sensitive components of food such as the organoleptic qualities of food. One of the reasons for the change in organoleptic quality after heating could be the alteration in primary, secondary, tertiary, or quaternary conformation of proteins as well as the destruction or the change of protein structure [56]. ...
The advancement of science and technology requires simple, easy-to-control, cheap, fast, and eco-friendly technologies for material synthesis, modification, and processing. Microwave technology provides an alternative due to its well-known characteristics such as selective heating, fast heating, reproducibility, flexible controls (via time, power, and frequency), high energy efficiency, and easy temperature control. In microwave-based material processing, a direct molecular interaction between electromagnetic energy and the material takes place and causes complex volumetric heating which is one of the technical challenges in material science development. This makes microwave energy one of the most important future resources for material processing. In this review, the importance and the uses of microwave technology primarily for material synthesis and modification that are abreast of recent advances will be summarized.
Graphical abstract
... The substantial strain-to-strain variation in the response to temperature adjustment also conforms with the hypothesis that cold adaptation confounds the results of temperature adjustment. The adjustment of the initial sample temperature has commonly been used to compensate compression heating [53,54] but results of the present study should be confirmed using equipment that allows either isothermal or adiabatic pressure treatments to minimize confounding factors. ...
High hydrostatic pressure processing (HHP) is used to reduce or eliminate pathogens and spoilage bacteria in food. The aim of this study was to investigate the effect of fat on the pressure resistance of E. coli in beef and a yogurt model system. Ground beef and pH-adjusted (pH 5.5) yogurt were adjusted to a fat content from 3 to 35% with adipose tissue and crème fraiche, respectively, and inoculated with E. coli. Samples were treated at 600 MPa and 20 or 30 °C for 3 min. Sample temperatures were adjusted prior to compression to compensate adiabatic heating, or not. An increased fat content of ground beef decreased the pressure resistance of E. coli. This was observed irrespective of the temperature history of the treatment. For example, at 20 °C, an increase in fat content from 15.5 to 24.4% increased treatment lethality by 6 log CFU/g for E. coli MG 1655. The correction for adiabatic heating increased or decreased pressure resistance at 20 °C in a strain-specific manner. Addition of crème fraiche to pH-adjusted yogurt did not alter the pressure resistance of E. coli (strains MG 1655 and DM 18.3), or increased resistance (E. coli AW 1.7 and AW 1.3). In summary, the pressure resistance of E. coli is dependent on the fat content, the food matrix and the temperature trajectory during processing. The effect of adipose tissue in meat matrix links the fat content of meat to lipid oxidation and the oxidative stress response.
... According to a recent report, S. aureus may grow when Aw exceeds 0.86, which could explain the detection of S. aureus in some samples (43). The changes in Aw may be attributed to the substances produced by the decomposition of proteins and fats, such as amino acids and fatty acids, which alter the osmotic pressure of the mixed system and consequently affect the Aw of fermented pork jerky (44,45). ...
Background
To determine the effect of different sterilization methods on shelf life and physicochemical parameters of fermented pork jerky.
Methods
Various sterilization techniques, including boiling, pasteurization, medium-temperature steam sterilization, high-temperature steam sterilization, ultrasonic sterilization, and ultraviolet sterilization, were employed in this study to treat vacuum-sealed fermented pork jerky. Changes in microbial populations, physicochemical parameters, and sensory evaluations were monitored throughout the storage period.
Results
The results indicated the presence of Staphylococcus aureus on the 24th, 21st, 33rd, 24th, 18th, and 15th days in pork jerky subjected to boiling (100°C, 20 min), pasteurization (85°C, 15 min), medium-temperature steam sterilization (105°C, 0.5 Pa, 30 min), high-temperature steam sterilization (121°C, 1.0 Pa, 20 min), ultrasonic sterilization (480 W, 30 kHz, 30 min), and ultraviolet sterilization (254 nm, 100 W/m2, 60 min), respectively. Coliforms, salmonella, and Shigella were not detected in any group during storage. The medium-temperature steam sterilization method yielded the most favorable microbiological results, with an aerobic plate count of less than 1.0 lg CFU/g. However, other physicochemical parameters and sensory evaluations were moderate, with total volatile basic nitrogen (TVB-N) and thiobarbituric acid reactive substances (TBARS) measuring 14.023 mg N/100 g and 0.427 mg MDA/kg, respectively, remaining within acceptable limits.
Conclusion
Therefore, considering microbiological indicators as the primary determinant of shelf life and taking into account other physicochemical parameters, the medium-temperature steam sterilization method was identified as the most suitable approach for extending the shelf life of fermented pork jerky while preserving its flavor.
... In commercial sterilization at 121 °C, cell rupture due to excessive heat treatment tends to soften the texture of meat products, which is more prone to water loss and hardening during storage, a common phenomenon (Barbosa-Cánovas et al., 2014). The sensory organ evaluations of the two processing methods were shown in Figure 1a. ...
The diced chicken with mushroom was taken as the research object to investigate the differences in quality and protein digestion characteristics between traditional (TD) cooked and prefabricated (ST) product. The results showed that compared to TD cooked, the acceptability and flavor of sensory evaluation of ST product decreased significantly, while the taste and chewiness improved remarkably. In addition, the bound and immobilized water were found transferred to free water indicated the water holding capacity decreased and meat softened. The analysis of gas chromatography-mass spectrometry (GC-MS) indicated that hexal, octanal and volatile substances from spices were the key substances causing flavor differences between the two methods and could be further distinguished by the electronic nose and tongue. The results of digestion in vitro showed that the protein digestibility, release rate of peptide and free amino-acid in the ST product were higher than that in the TD cooked. The contents of α-helix and β-sheet decreased with the increase of digestion time in the two methods, while the α-helix content of the ST product was lower during the first 60 min of intestinal digestion than that in TD cooked. These findings give a new insight into the associations of processing methods with meat quality. © 2023, Sociedade Brasileira de Ciencia e Tecnologia de Alimentos, SBCTA. All rights reserved.
... Heatinduced changes in the components of meat alter its texture, and one of the most essential aspects of muscle foods is that they are abundant in protein, with changes in connective tissue tenderizing and myofibrillar protein hardening increasing toughness. Thermal processing increases toughness by shrinking intramuscular collagen between 60 and 70°C, denaturing meat myofibrillar proteins between 40 and 50°C, and shrinking and dehydrating actomyosin between 70 and 90°C ( Barbosa-Cánovas et al., 2014). ...
Abstract
The need for high-quality and safe food has been steadily increasing. Whereas, the food processing sector is looking for new cost-effective, quick, and more efficient technologies than existing processes. With its vast application in numerous processes, ultrasonic technology has transformed the food processing industry, acting as a sustainable as well as low alternative. This nondestructive technology has various benefits, including faster procedures, increased process efficiency, reduction of process stages, higher product quality as well as retention of product attributes (nutrition value, texture, organoleptic features), and longer shelf life. Electromagnetic waves, on the other hand, are now often used for food processing in commercial, and industrial microwave ovens. Microwaves induce molecular mobility by causing ionic particles to migrate or dipolar particles to rotate. When considering the possible applications of microwave technology in the food sector, it is clear that microwaves offer numerous benefits, including time savings, improved final product quality (taste, color, and nutritional content), and rapid heat generation. However, microwave treatment for food processing with advanced technology has a favorable effect on energy, time, and nutritional value. Ultrasound and microwave (US-MW) are new technologies utilized to improve heat and mass transmission since they are inexpensive, simple, and energy-efficient. The current review focuses on the effects of ultrasonic and microwave processing on the textural, and nutritional aspects of food products and how process variables influence these properties.
... Heatinduced changes in the components of meat alter its texture, and one of the most essential aspects of muscle foods is that they are abundant in protein, with changes in connective tissue tenderizing and myofibrillar protein hardening increasing toughness. Thermal processing increases toughness by shrinking intramuscular collagen between 60 and 70°C, denaturing meat myofibrillar proteins between 40 and 50°C, and shrinking and dehydrating actomyosin between 70 and 90°C ( Barbosa-Cánovas et al., 2014). ...
Fermentation and emulsification are some of the basic techniques that are used to preserve the quality of food, prolong shelf life and provide special taste and texture. There are different technologies that assist them during the process. Ultrasound and microwave are two modern technologies that are used in many food processing techniques; also have their individual effects on fermentation and emulsification. However, these days microwave-ultrasound-assisted (hybrid processing) processing techniques are used in order to cover the defects possessed by each other. This synergic microwave-ultrasound technology has been studied widely these days. As both of these technologies are less expensive and more effective and valuable. This combination ranges from simple to flow system modification, safe and possible to use. As compared to the individual effect of ultrasound and microwave technologies; microwave-assisted ultrasound synergistically Promotes the peptide content, phenolic compound, and preserves bioactive properties of the products during fermentation and while improving the overall process efficiency it also enhances extraction, antioxidant and emulsification properties. microwave-assisted ultrasound intensifies the process and completes it in a short time with more accuracy. In this chapter, a brief review throws light on the individual and in recent developments combine effects of MW and US on fermentation and emulsification process.
... Retort processing is one of the most widely used thermal processes for commercial production of packaged food products with a long shelf life at room temperature [6]. In general, a high temperature (>121.1 • C) and a pressure higher than the atmospheric pressure (1.3-1.5 atm) are used as reference processing conditions for the retort process [8]. ...
Thermal processing of white radish using retort sterilization at different temperatures was investigated according to the dimension of the package. Four different samples with the same weight and volume were placed in packages with different dimensions. The degree of sterilization (i.e., F0-value) at the cold point targeted at 6 min was determined based on experimental data and heat transfer simulation. The sterilization time was considerably increased with a decrease in surface area to unit volume ratio (φ) at each temperature. The sterilization time for the sample with the highest φ (155.56) was approximately five times faster than the sample with the lowest φ (72.22) at all heating temperatures. Numerical simulation conducted with a proper heat transfer coefficient (h) showed mostly good agreement with the experimental data (RMSE < 2 °C). Changes in color and total phenolic content were higher for samples heated at higher temperatures. Hardness values of white radish samples measured for center and edge parts separately were more uniform for samples with a high φ. Results in this study suggest that optimizing heating conditions of root vegetables must consider their package dimensions to satisfy quality attributes after sterilization. Numerical simulation can be utilized as a useful tool to design the sterilization process.
... Heatinduced changes in the components of meat alter its texture, and one of the most essential aspects of muscle foods is that they are abundant in protein, with changes in connective tissue tenderizing and myofibrillar protein hardening increasing toughness. Thermal processing increases toughness by shrinking intramuscular collagen between 60 and 70°C, denaturing meat myofibrillar proteins between 40 and 50°C, and shrinking and dehydrating actomyosin between 70 and 90°C ( Barbosa-Cánovas et al., 2014). ...
... Due to the low thermal conductivity of food materials themselves, it requires a very long time to achieve sufficient thermal lethality of target microbes. However, long-time thermal processing leads to unavoidable thermal degradation of nutritional and sensory quality for food products (Barbosa-Cánovas et al., 2014;Cavalcante et al., 2021;Vadivambal & Jayas, 2010). ...
Microwave thermal processing is a promising technology to greatly improve product quality by achieving high‐temperature short‐time (HTST) processing for solid foods. And the non‐thermal effect of microwave fields on nutritional quality is a major public concern. To distinguish the non‐thermal effect of microwave fields, the thermal effect of HTST processing should be revealed first. The objective of this study was to investigate the effects of different HTST processing on quality of Pacific saury fillets using extracted fatty acids as the indicator. A self‐developed thermal processing system was used to conduct the HTST processing with different heating rate (5.48–18.30°C/min), maximum heating temperature (123, 133 °C), and thermal processing level (F0 = 3.0 min, 6.0 min). Results showed that the extraction coefficient of lipids and fatty acids decreased with increasing heating rates, which implied less thermal damage of fish tissue, while higher thermal processing level increased these extraction coefficients. However, higher maximum processing temperature caused serious thermal damage of fatty acids, especially for PUFAs. Furthermore, changing pattern of each fatty acid during different HTST processing was revealed, which provided fundamental data for designing microwave thermal processing and exploring microwave non‐thermal effects. The HTST processing had great potential to improve the quality of solid foods. However, HTST processing with extra high temperature brought damage to fatty acids.
... high-temperature and high-pressure sterilization has seriously damaged its flavor, which is not conducive to the development of Tan sheep meat processing industry (5,6). The central kitchen developed earlier in America, Japan and many developed countries in Europe (7). ...
Taking the eutectic point as the final freezing temperature, the differences of flavor substances of in hand grab mutton (HGM) frozen at three rates of 0. 26 cm/h (−18°C), 0.56 cm/h (−40°C) and 2.00 cm/h (−80°C) were determined and analyzed. The results showed that the flavor of HGM decreased significantly after freezing. With the increase of freezing rate, the contents of aldehydes, alcohols, ketones, acids, esters, others, free amino acids and 5′-nucleotides were higher, and the content of specific substances was also generally increased. All samples from unfrozen and frozen HGM could be divided into four groups using an electronic nose based on different flavor characteristics. Seven common key aroma components were determined by relative odor activity value (ROAV), including hexanal, heptanal, octanal, nonanal, (E)-oct-2-enal, (2E,4E)-deca-2,4-dienal and oct-1-en-3-ol. The higher the freezing rate, the greater the ROAVs. Taste activity values calculated by all taste substances were far <1, and the direct contribution of the substances to the taste of HGM was not significant. The equivalent umami concentration of HGM frozen at −80°C was the highest. These findings indicated that higher freezing rate was more conducive to the retention of flavor substances in HGM, and the flavor fidelity effect of freezing at −80°C was particularly remarkable.
... Microwave technology has become a prominent method in the food industry for creating safe, high-quality processed products. In particular, MATS has gained interest for its ability to effectively and uniformly heat nonhomogenous, complex food systems (Barbosa-Cánovas et al., 2014). Due to its even, volumetric heating capabilities, shorter processing times, and higher rates of heat transfer, MATS processing can thermally process foods while retaining higher concentrations of flavors and nutrients than conventional methods, resulting in higher quality and more appealing products (Auksornsri et al., 2018). ...
The purpose of this study was to examine emotional and liking responses to foods designed for older adults and made using microwave‐assisted thermal sterilization technology (MATS). Six chicken pasta meals (three each with and without herbs) were formulated with three concentrations of salt at 100%, 75%, and 50%. Seventy‐six community‐dwelling older adults conducted sensory and emotional evaluations. Sensory testing involved measuring liking of various sensory attributes using a 9‐point hedonic scale, Just‐about‐right scales to measure appropriateness of the intensity of the attributes, and check‐all‐that‐apply questions to identify perceived flavor and texture attributes. EsSense25 methodology was used for capturing food‐evoked emotional responses. Significant differences existed in all measured sensory attributes and in 14 out of the 25 tested emotions across the six meals. Liking scores for all pastas with herbs and high salt pasta with no herbs were not significantly different for all tested attributes and fell between neither like nor dislike and like slightly on the 9‐point hedonic scale. These samples were also associated with positive emotions related to energy and activation. Low‐salt pastas with no herbs were consistently the least liked samples and evoked negative emotions. Results show that sodium content can be reduced by up to half when herbs are added to microwave‐processed pasta meals without compromising liking.
Practical Application
Chicken pasta meals manufactured using microwave‐assisted thermal sterilization technology are acceptable to community living individuals 60 years and older. Emotional responses to the meal are positive. When formulating these meals, herbs can be added to lower sodium content formulations to improve liking and increase the number of positive emotions associated with the meal. Microwave‐assisted thermal sterilization, sodium reduction, emotional responses, consumer liking, older adults.
As the number of households with pets has increased worldwide, there is a growing trend of accepting pets as family members. Consequently, the pet food market has seen the emergence of concepts such as “human-grade,” “raw (PMR and BARF),” and “no synthetic additives” pet food. These concepts not only fulfill essential nutrients but also consider the health and habits of pets, a crucial aspect that should be at the forefront of our work. However, these types of pet food are prone to microbial contamination and component alterations caused by heat. Current studies and products have recently been developed overseas to apply non-thermal sterilization technologies to pet food commonly used in the food industry. In contrast, the domestic standards for non-thermal sterilization in pet food are insufficient. Therefore, a comprehensive review of non-thermal sterilization technologies, such as high-pressure processing (HPP), radiation, and plasma predominantly applied in the international pet food market, is deemed necessary. This review is expected to provide guidelines for non-thermal sterilization standards in domestic pet food, thereby laying the foundation for the safe production of raw pet food.
Ultrasound is regarded as an effective and promising non-thermal technology, and it is increasingly investigated in recent years in the meat field in order to speed up the processing or improve the quality properties. This review comprehensively summarizes the contributions of ultrasonic application in seven aspects (curing, tenderization, emulsification, freezing, thawing, sterilization and flavor) in the processing of meat and/or its products, discussing the different types of application with some examples, and deeply explaining the involved mechanisms. Ultrasound-triggered cavitation effect is confirmed to be a pretty important reason for the promotion of processing efficiency and quality attributes of meat and/or its products. The present work will provide an in-depth systematic review on the knowledge of ultrasonic technology for a better understanding of the positive aspects of the application of such technology in the meat field.
In terms of efficiency and speed, microwave heating outperforms other heating techniques by a wide margin. This is especially helpful in today’s fast-paced, time-constrained world. Protein is one of the many nutrients that the body needs to function properly. It is involved in many physiological processes in humans as well as other animals. It is crucial to comprehend how microwave heating affects proteins because it has an impact on the nutritional value of food as a whole. Microwave heating has the ability to alter the kinetics of how peptides and proteins fold, according to experimental data. The delicate natural folded structures of these biomolecules are maintained via complex hydrogen bonds, disulfide bonds, and hydrophobic interactions. However, more thorough investigation is required to completely understand the effects of microwave heating on protein structures. These studies should take into account variables like various power levels, exposure times, and meal composition because they might considerably affect the results. This chapter aims at understading various effects observed on protein quality in food products subjected to microwave heating. The development of improved cooking procedures to maintain protein integrity and nutritional value will benefit from an understanding of how these factors interact with protein structures during microwave heating.
Recently, as the concept of pet food that satisfies both nutritional needs and the five senses has evolved, so too has the demand for effective pet food non-thermal sterilization methods. Prominent non-thermal technologies include high-pressure processing, plasma, and radiation, which are favored for their ability to preserve nutrients, avoid residues, and minimize compositional changes, thereby maintaining quality and sensory properties. However, to assess their effectiveness on pet food, it is essential to optimize operational parameters such as pressure levels, plasma intensity, radiation dosage, and temperature. Further studies are needed to evaluate microbial sterilization efficacy and sensory attributes. This exploration is expected to lay the groundwork for preventing zoonotic diseases and improving the production of high-quality pet food.
Food is one of the most necessary needs since human civilization. For Muslims, it is mandatory to consume halal food. From a halal authentication perspective, adulteration of food products is an emerging challenge worldwide. The demand for halal food consumption has resulted in an ever‐increasing need for halal product validity. In the market, there are several food products in which actual ingredients and their source are not mentioned on the label and cannot be observed by the naked eye. Commonly nonhalal items include pig derivatives like lard, pork, and gelatin derivatives, dead meats, alcohol, blood, and prohibited animals. Purposely, various conventional and modern methods offer precise approaches to ensure the halalness and wholesomeness of food products. Conventional methods are physiochemical (dielectric) and electrophoresis. At the same time, modern techniques include high‐pressure liquid chromatography (HPLC), gas chromatography (GC), electronic nose (E‐Nose), polymerase chain reaction (PCR), enzyme‐linked immunosorbent assay (ELISA), differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), near‐infrared (NIR) spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. This review intends to give an extensive and updated overview of conventional and modern analytical methods for ensuring food halal authenticity.
The novelty of this study is the investigation of the effect of different heat treatments and, simultaneously, the effect of different fat levels on the quality of pork liver pâtés. Hence, this study aimed to evaluate the effect of heat treatment and fat content on selected properties of pork liver pâté. For this purpose, four batches of pâtés with two different fat contents (30 and 40% (w/w)) and two different heat treatments (pasteurisation: target temperature 70 °C, holding time of 10 min; sterilisation: target temperature 122 °C, holding time of 10 min) were manufactured. Chemical (pH, dry matter, crude protein, total lipid, ammonia, and thiobarbituric acid reactive substances (TBARS)), microbiological, colour, textural, rheological, and sensory analyses were performed. Both different heat treatment and fat content affected most of the parameters observed. Sterilisation ensured the commercial sterility of the manufactured pâtés, resulting in elevated TBARS values, hardness, cohesiveness, gumminess and springiness, and increased rheological parameters (G′, G″, G*, and η*), as well as colour changes (decrease in L* and increase in a*, b*, and C* values) and deterioration of appearance, consistency, and flavour also being detected (p < 0.05). Higher fat content caused similar variations in the textural and viscoelastic properties, i.e., the increase in hardness, cohesiveness, gumminess and springiness, and also in G′, G″, G*, and η* (p < 0.05). However, the colour and sensorial parameters changed in different ways compared to the changes induced by the sterilisation effect. Overall, the observed changes might not be desirable for some consumers and further research would be appropriate to improve especially the sensorial attributes of sterilised pork liver pâtés.
The current study aimed to assess the impact of chitosan coating (0.005 g/mL) combined with thermal treatment (85 °C for 30 min) on tenderness, lipid and protein oxidation, bacterial diversity, and volatile flavor compounds in braised duck leg meat under vacuum packaging during refrigerated storage (4 °C for 15 days). The findings revealed that the three preserved treatments significantly increased tenderness from days 1 to 3. There was a substantial decrease from days 6 to 12 compared to the control, but no significant differences were observed on day 15. Compared with the control, the three preserved treatments reduced TBARS values by 25.8%-78.6% (from days 6 to 12) and total sulfhydryl concentrations by 24.1%-75.7% (from days 3 to 9). The combination treatment had the lowest values (carbonyl concentration, TVC, and TEC) compared to the chitosan coating and thermal treatment, indicating a significant synergistic effect. The proportions of the four primary spoilage organisms, Brochothrix, Weissella, Acinetobacter, and Pseudomonas, were 74.8%, 76.3%, 70.7%, and 49.7% in control, chitosan coating, thermal treatment, and combination treatment, respectively. The combination treatment produced the most volatile flavor compounds (38 compounds) at the end of storage (15 days). Hexanal, 1-nonanal, 1-octen-3-ol, and 2, 3-octanedione were the main volatile flavor compounds, and the average relative peak area was above 80. Therefore, chitosan coating and thermal treatment could be developed as synergistic methods to preserve braised duck meat.
Unlabelled:
Heat penetration characteristics of different vegetable products were investigated during retort processing. A custom-developed variable temperature retort-sterilizer allowed us to test the following target retort-temperatures; 120, 130, 140, and 150 °C, combined with the following holding times: 1, 3, 5, 7 min. Radish showed the highest heating rate (9.56 ± 0.21 °C/min) among the tested vegetables, including radish, carrot, and potato. Textural qualities of retort-processed vegetables showed a close correlation with thermal dose. Hardness of potato was 3.07 ± 0.07 N after retort processing at 120 °C for 7 min, with a thermal dose of 127 ± 7 k °C s. Better hardness (3.72 ± 0.06 N) was obtained after retort processing at 150 °C for 3 min, with a thermal dose of 122 ± 6 k °C s. The data reported herein indicate that retort temperature should be appropriately controlled for different vegetable products based on their specific heat-penetration characteristics.
Supplementary information:
The online version contains supplementary material available at 10.1007/s10068-023-01247-8.
Meat processing represents an inevitable part of meat and meat products preparation for human consumption. Both thermal and non-thermal processing techniques, both commercial and domestic, are able to induce chemical and muscle’s proteins modification which can have implication on oxidative and sensory meat characteristics. Consumers’ necessity for minimally processed foods has paved a successful way to unprecedented exploration into various novel non-thermal food processing techniques. Processing of meat can have serious implications on its nutritional profile and digestibility of meat proteins in the digestive system. A plethora of food processing techniques can potentially induce alterations in the protein structure, palatability, bioavailability and digestibility via various phenomena predominantly denaturation and Maillard reaction. Apart from these, sensory attributes such as color, crispness, hardness, and total acceptance get adversely affected during various thermal treatments in meat. A major incentive in the adoption of non-thermal food processing is its energy efficiency. Considering this, several non-thermal processing techniques have been developed for evading the effects of conventional thermal treatments on food materials with respect to Maillard reactions, color changes, and off-flavor development. Few significant non-thermal processing techniques, such as microwave heating, comminution, and enzyme addition can positively affect protein digestibility as well as enhance the value of the final product. Furthermore, ultrasound, irradiation, high-pressure processing, and pulsed electric fields are other pivotal non-thermal food processing technologies in meat and meat-related products. The present review examines how different thermal and non-thermal processing techniques, such as sous-vide, microwave, stewing, roasting, boiling, frying, grilling, and steam cooking, affect meat proteins, chemical composition, oxidation, and sensory profile.
The effect of steaming (100 ℃), boiling (100 ℃), frying (160 ℃) and high-pressure steam (121 ℃) on crayfish (Procambarus clarkii) quality was compared. The results showed that all four treatments have sterilization effect. The color, taste and texture of crayfish treated by steaming and boiling were better than by frying and high-pressure steam. Among the four cooking methods, the frying group has the highest cooking loss (32%) and thiobarbituric acid value (0.71 mg/kg). The effects of four thermal treatment on the content of astaxanthin of crayfish meat were significantly different. By comparing the content of volatile flavor compounds (VOCs), it was found that the crayfish treated by steaming and frying containing more species VOCs than the other two methods. For cooking crayfish, steaming could be beneficial for maintaining good edible quality. These results would be helpful for crayfish processing and new products development.
Microwave-assisted induction heating (MAIH) is a complex heating process characterized by rapid and uniform heating based on a combination of microwave heating (power: 1000 W; frequency: 2450 MHz) applied from above and electromagnetic induction heating (power: 1500 W) applied from below. In this study, we assessed the utility of MAIH in processing the flesh of barramundi (Lates calcarifer), an important aquaculture species in Asian countries. To determine the effects of different heating conditions on the microbial contamination and physicochemical qualities of barramundi meat, fresh barramundi meats (100 g) were sealed in heat-resistant crystallized polyethylene terephthalate containers containing 150 mL of saline solution, and were subsequently heated in MAIH to 90 °C or 70 °C and held to different time. The results revealed that in response to an increase in the duration of heating, there were reductions in the aerobic plate count, psychrotrophic bacteria count, hydrogen sulphide-producing bacteria count, and coliform count, along with lower contents of total volatile basic nitrogen, in treated samples. Conversely, with a prolongation of the time exposed to heat, we detected increases in the L* (lightness),W (whiteness),ΔE(colour difference), and texture (hardness and chewiness) of fish meat, whereas there was a reduction of a* (redness). When the samples were heated for at least 110 s to 90 °C or for at least 130 s to 70 °C, the barramundi meats obtained appeared to be fully cooked with microbial counts below the limits of detection. In addition, under both heating conditions, thermal imaging revealed a uniform distribution of temperature within treated samples. Furthermore, monitoring of temperature profiles at central points in fish samples revealed that maximum temperatures of 97 °C and 79 °C were reached in response to MAIH processing at 90 °C for 110 s and 70 °C for 130 s, respectively. Thus, on the basis of the quality considerations of appearance, microbial count, and texture, the recommended optimal heating conditions for barramundi meats produced using MAIH are 90 °C for 110 s and 70 °C for 130 s.
Industrial relevance
The MAIH equipment is a novel thermal processing technology and allows food to be heated and pasteurized simultaneously after the package is sealed, eliminates issues of secondary contamination due to the need for subsequent packaging, and extends the shelf life. MAIH technology, therefore, serves as a viable future alternative for thermal processing of manufacturing refrigerated ready-to-eat seafood.
Pot-honey is a highly valuable product obtained by stingless bees that commonly predominate in tropical habitats and constitutes an interesting alternative to the typical production and commercialization of Apis mellifera honey. Although the production in most places is purely artisanal, the prospect of growth in the commercialization of this type of honey is promising. However, there are still problems of handling and conservation, fundamentally linked to poor hygienic practices that lead to the proliferation of microorganisms. Since the water content in pot-honey is typically higher than reported for A. mellifera honey, it is more susceptible to degradation if treatments aimed at sanitizing the product are not carried out. In this sense, pasteurization is presented as an accessible alternative for beekeepers, but it does not guarantee the elimination of spores, which represent a risk to the health of consumers. In this study, tyndallization was tested as a method to sanitize pot-honey, based on heating/cooling cycles that promote spore germination, facilitating their elimination. The results found show treatment at 80 °C for 15 min promoted an increase in HMF levels and a decrease in diastase activity, although between the limits defined in regulations set for A. mellifera. The shelf-life study showed that free acidity limited the storage time, overpassing an acceptable value after 200 days at 23 °C. In conclusion, this study has demonstrated optimum conditions for honey processing through the elimination of the microbiological load it contains. Tyndallization is presented as a viable and accessible alternative for meliponiculturists to improve food hygiene and preserve it for a reasonable time under typical honey storage conditions. The information obtained will allow establishing the bases for adequate control of honey from T. angustula bees in the different stages of the distribution chain.
Microwave-assisted induction heating (MAIH) is an emerging thermal processing technology that combines microwave and induction heating to provide rapid and even heating of food. A research found that the optimum MAIH cooking temperature for hard clams was 130 °C for 110 s or 90 °C for 130 s. The purpose of this work was to investigate whether MAIH could delay or not the loss of quality and prolong the shelf life of clams. Fresh clams were heated via MAIH to 130 °C for 110 s and to 90 °C for 130 s, respectively, and compared to the traditional boiling method of 90 °C for 150 s. Cooked clams were stored at 4 °C for 30 days to determine changes in microbiological quality and physicochemical properties. The results showed the undetectable aerobic plate count (APC) and psychrotrophic bacteria count (PBC) in the samples when heated via MAIH for the first 20 days of storage; thereafter, the counts increased gradually. By the end of the storage period, the final counts were approximately 4.0 log CFU/g. The initial APC and PBC in the sample heated with boiled water were at approximately 3.20 log CFU/g, which then increased over time to reach 7.66 log CFU/g and 8.06 log CFU/g, respectively, by the end of the storage period. After 30 days of storage, the total volatile basic nitrogen (TVBN) in the MAIH-treated samples was significantly lower than that in the water-boiled samples, by less than 36 mg/100 g. In terms of color, the lightness (L*) and whiteness (W) of all samples decreased gradually, while the redness (a*) and yellowness (b*) increased. In terms of texture, the MAIH-treated samples retained greater hardness, cohesiveness, and chewiness than the water-boiled samples (p < 0.05). Based on the above findings, compared to the traditional heating method of water boiling, the treatment of clam samples with MAIH retarded the degradation of texture, and inhibited the increase of TVBN and the growth of microorganisms during refrigerated storage. Thus, MAIH processing can prolong the storage life of the heat-treated clams from 10 days (when treated with boiling water) to 30 days at 4 °C.
Microwave is a form of electromagnetic radiation that has high penetration and heating efficiency in food processing. Uneven heating is the main problem of microwave processing, especially in solid foods. Fluid and semifluid media, which are good carriers in microwave processing, have uniform dielectric properties and good material fluidity. Herein, we review the development, application prospects, and limitations of microwave in fluid and semifluid food processing and the research progress in microwave heating with steam as carrier. The mixture of generated steam and tiny micro droplets from food material under the action of microwave can absorb microwave and transfer heat evenly, which effectively improves the uniformity of microwave heating. Due to the relatively uniform dielectric properties and consistent texture of fluid and semifluid food materials, uneven heating phenomenon during their microwave processing can be significantly inhibited. Based on the development of microwave heating technology and equipment design, the microbial inactivation and enzyme inhibition in fluid and semifluid food were improved and food product with better retention of nutrients and sensory profile were produced. Also, microwave radiation can be used to prepare the printing material or process the printed product for 3D food printing, which enhances the added value of 3D printed products and the personalization of food manufacturing. In future research, intelligent control technology can be applied in the microwave processing of fluid and semifluid food materials for various applications. Therefore, the processing conditions can be adjusted automatically.
The two-dimensional cylindrically shaped multiphase meat sample was modelled for microwave processing for two different interaction techniques i.e., lateral and radial during mono-mode operation of waveguide. The study was aimed to analyze the effect of volume fraction and sample size along with the duration of the procedure on the heat distribution corresponding to specified frequency and intensity of microwave. Procedure exhibiting higher heating rate and lower thermal non-homogeneity was set as the deciding factor for an optimal heating scheme. In order to achieve optimal processing at both 915 and 2450 MHz frequency, rotation of smaller samples and non-rotation of larger samples were recommended in most of the case studies; however, few exceptions were also observed and reported. In addition, reciprocity between volume fraction, intensity of the microwave radiation and procedure duration was also discussed. Overall, the present study would guide the studies on the microwave processing of two-dimensional multiphase meat.
The development and scope of using various food preservation methods depends on the level of consumers’ acceptance. Despite their advantages, in the case of negative attitudes, producers may limit their use if it determines the level of sales. The aim of this study was to evaluate the perception of seven different food processing methods and to identify influencing factors, such as education as well as living area and, at the same time, to consider whether consumers verify this type of information on the labels. Additionally, the study included the possibility of influencing consumer attitudes by using alternative names for preservation methods, on the example of microwave treatment. The results showed that conventional heat treatments were the most preferred preservation methods, whereas preservatives, irradiation, radio waves and microwaves were the least favored, suggesting that consumers dislike methods connected with “waves” to a similar extent as their dislike for preservatives. The control factors proved to significantly modify the evaluation of the methods. The analysis of alternative names for microwave treatment showed that “dielectric heating” was significantly better perceived. These research findings are important as the basis for understanding consumer attitudes. Implications for business and directions of future research are also indicated.
Novel thermal processing technologies, such as radiofrequency heating, microwave heating and ohmic heating, Infrared heating, and inductive heating have been developed and tried successfully for different food products. These techniques improve the efficiency and effectiveness of the heating process while maintaining product quality and safety. These techniques eliminate the factor affecting organoleptic properties and maintain the nutritional profile of food products. Novel thermal technologies are dependent on heat generation directly inside the material, which increases energy utilization, thereby overall energy efficiency of the heating process. These processes are dependent on inherent properties of food material, which are complex in nature such as electrical resistance, thermal conductivity, water content, porosity, pH, and rheological properties. This chapter, encompassing the use of novel thermal technologies, will help to understand the underlying principle, mechanism, advantages, disadvantages, and limitations associated with each technique applied to different food products. It will help to understand suitable technology to inactivate the enzyme, spores, bacteria, microbes in a specific food product.
Thermal processes are the most applied methods to make food meet the safety and quality requirements of consumers. However, food heating by conventional methods is associated with several undesirable effects on nutritional and sensorial properties. Designing an innovative thermal process that focuses on minimal, rapid, uniform, and economic heating is of great importance. Microwave heating has numerous advantages over conventional methods. Thanks to its volumetric and rapid heating, microwave technology has several applications in food processing. Nevertheless, non‐uniform heating remains the main drawback of microwave heating. Combination of microwave heating with conventional and/or other innovative heating methods have been widely investigated in the literature to overcome this problem. In this chapter, the theorical principles and the governing equations of microwave interactions with food materials are presented. In addition, the applications of microwave heating for food processing and the efficiency of recent improvements are reviewed.
In pressure-assisted thermal sterilization process (PATS), most of the microbial inactivation occurs under a combination of high temperature and pressure conditions for which meaningful experimental isothermal/isobaric (static) survival data are rarely if ever available. Therefore, a kinetic survival model for the targeted microbe, the magnitudes of its parameters, and the pressure’s direct contribution to the process lethality, i.e., besides the processing temperature elevation, must be determined mathematically from experimental survival ratios obtained after the food cooling at the end of dynamic treatments. At least in principle, this can be achieved with the endpoints method, explained and demonstrated with the aid of simulated realistic dynamic temperature and pressure profiles. The pressure’s net (unmediated) contribution to the process lethality can be expressed as equivalent time at the processing temperature, or as the added number of decades’ reduction to the treatment’s final survival ratio had it been reached in a purely thermal process having the same temperature profile. The pressure’s role is also manifested in the coefficients of a special pressure dependency term incorporated into the dynamic inactivation kinetics model. This term indicates whether the process lethality rises monotonically with temperature and pressure or there exists an optimal combination of the two. The expanded rate model can be used to simulate and examine the efficacy of existing or contemplated PATS processes by varying the temperature and pressure profiles, and/or by modifying the targeted microbe’s survival parameters.
Taking into account the importance of temperature and temperature control could make high-pressure sterilization economically more feasible.
The aim of the present study was to evaluate the effect high hydrostatic pressure (HHP) processing (350–550MPa for 30, 90 and 150s) on microbial quality as well as physico-chemical and bioactive compounds of pomegranate juices during 35days of storage at 4°C. Antioxidant activity, phenolic content and color values (L*, a* and ΔE) were determined. The microbiological results showed that HHP-treatment at or over 350MPa for 150s resulted in a reduction of the microbial load around 4.0logcycles, and were sufficient to keep microbial populations investigated below the detection limit during the whole storage period. Therefore, these treatments were able to extend the microbiological shelf-life of pomegranate juice stored at 4°C for more than 35days. All HHP-treated samples showed a slight reduction in antioxidant capacity during storage time. Phenolic content increased significantly (p
The application of high pressure offers some interesting opportunities in the processing of muscle-based food products. It is well known that high-pressure processing can prolong the shelf life of meat products in addition to chilling but the pressure-labile nature of protein systems limits the commercial range of applications. High pressure can affect the texture and gel-forming properties of myofibrillar proteins and, hence, has been suggested as a physical and additive-free alternative to tenderize and soften or restructure meat and fish products. However, the rate and magnitude at which pressure and temperature effects take place in muscles are variable and depend on a number of circumstances and conditions that are still not precisely known. This review provides an overview of the current knowledge of the effects of high pressure on muscle tissue over a range of temperatures as it relates to meat texture, microstructure, color, enzymes, lipid oxidation, and pressure-induced gelation of myofibrillar proteins.
Prawn ‘kuruma’ was prepared from Indian white shrimp (Fenneropenaeus indicus), packed in conventional 301 × 206 and 401 × 411 aluminium cans and in thin profile retort pouches having a three-layer configuration of 12.5 μ polyester, 12.5 μ aluminium foil and 85 μ cast polypropylene of size 16 × 20 cm and 17 × 30 cm. The physico-chemical tests conducted on these containers showed their suitability for thermal processing. Prawn to kuruma ratio of 65:35 was maintained in all the containers and heat processed to equal lethality in an over pressure autoclave with the facility to record the time–temperature data, F0 value and cook value. The process time was calculated by using formula method. The processing in 16 × 20 cm and 17 × 30 cm retortable pouch resulted in 35.67% and 56.56% reduction in process time compared with 301 × 206 and 401 × 411 cans, respectively, with equal pack weight. The amino acid content did not vary considerably in both containers. In the canned samples the reduction of sulfhydryl content was 50.54% more when compared with the pouched product. Products packed in pouches were found to be superior to canned products with regard to sensory and textural attributes such as colour, firmness, hardness, chewiness, and overall acceptability.
During the late 1980s and early 1990s, the research activity on high hydrostatic pressure (HHP) was focused on evaluating the biological effects of pressure on microorganisms, foods, and food components. Most researchers followed an exploratory approach to identify potential applications of this technology in food processing and preservation. Examples of HHP food applications are microbial and enzyme inactivation (Hendrickx et al., 1998; Farkas and Hoover, 2000), promotion of protein conformational changes (Balny et al., 1997; Gross and Jaenicke 1994), and starch gelatinization (Douzlas et al., 1998).
In order to successfully produce food products with maximum quality, each stage of processing must be well-designed. Unit Operations in Food Engineering systematically presents the basic information necessary to design food processes and the equipment needed to carry them out. It covers the most common food engineering unit operations in detail, including guidance for carrying out specific design calculations. Initial chapters present transport phenomena basics for momentum, mass, and energy transfer in different unit operations. Later chapters present detailed unit operation descriptions based on fluid transport and heat and mass transfer. Every chapter concludes with a series of solved problems as examples of applied theory.
In the meat-processing industry, the manufacture and marketing of canned meats and meat products is sometimes separated into two areas, (1) pasteurized and (2) shelf stable products. Canning of pasteurized canned-meat products is generally closely associated with the manufacture of other pasteurized processed meat products. However, shelf stable canned meats and canned-meat products usually fall under the heading of grocery products, and, in the largest meat-processing companies, are usually the marketing responsibility of a grocery products department. Invariably, all products handled by this department of a meat-processing company are shelf stable.
Electromagnetic heating, such as microwave and radiofrequency (RF) heating, nds applications in several food processes in industry and at home, including reheating, precooking, cooking, tempering, baking, drying, pasteurization, and sterilization. Electromagnetic heating processes are governed by the material properties called dielectric properties. As microwave heating gains increasing use in food-processing systems in industry and in the home, knowledge of dielectric properties becomes increasingly critical for consistent and predictable product, process, and equipment development. In this chapter, dielectric properties are dened, their roles in heating systems are summarized, measurement of the properties is described, and frequency, temperature, and composition dependence of the properties is discussed for groups of foods from available literature data. Short compilations of data are also provided.
Chicken leg and breast meat samples were cooked in a microwave oven, electric oven and boiling water, and cooking loss, yield, nutritive contents and their retentions after cooking, thiobarbituric acid (TEA) value, total mesophile aerobic bacterial (TMAB) counts and sensory properties were determined. Cooking losses of leg and breast meat were 29.20% and 24.80% respectively. The highest yield (79.69%) was in a breast meat cooked in a microwave oven (P<0.01). Moisture retentions of leg meat cooked in an electric oven and breast meat cooked in water were the lowest (P<0.01). While the fat retention of leg meat was not affected by the cooking methods, microwave cooking caused the highest retention in breast meat (P<0.05). Thiamin content in meat was the most affected by the boiling method and the lowest thiamin retention calculated was in meat cooked in water. All cooking methods affected the malonaldehyde content of cooked meat compared with the malonaldehyde content of raw meat (P<0.01 ) and was increased 5.5 fold. Microwave cooking did not reduce the TMAB counts of meat significantly. In sensory evaluation, while color and general acceptability scores of leg meat cooked in a microwave oven were lower than of those cooked in en electric oven, the color and flavor scores of breast meat cooked in a microwave oven were lower than of those cooked in an electric oven.
Sterilising trials on model systems have been carried out using high pressure to 15,000 bar. The trials performed have taken into consideration the spores destruction (Clostridium sporogenes PA 3679, ATCC 7955) and some enzymes inactivation (PPO, POD e PME). The stability of different model systems has been reached by means of contemporaneous pressure-heat treatments only. Looking to the moderate temperature reached during very short times, the process leads to see interesting perspectives concerning the quality improvement of sterilised foodstuffs.
High-pressure processing (HPP) destroys pathogenic and spoilage organisms while keeping food chemistry basically intact and enables pasteurization of foods with minimal effects on taste, texture, appearance, or nutritional value. The principles that govern the behavior of foods under pressure include Le Chatelier's principle, principle of microscopic ordering, and isostatic principle. A typical HPP process uses food products packaged in a high-barrier and flexible pouch or a plastic container. The rapid heating and cooling resulting from HPP treatment offer a unique way to increase the temperature of the product only during the treatment, and to cool it rapidly. Sufficient time after food treatment should be allowed to confirm that sub-lethally injured organisms do not recover after validating an HPP pasteurization process.
The validation of high-pressure processes for low-acid foods was discussed. High pressure processing was considered as a conventional thermal process requiring compression heating. A 12-D process was validated with a biological validation using Clostridium botulinum spores and established using a kinetic approach. HPP was stated to be a technology that enabled processors to make convenient food items with fresh like attributes and natural-looking colors with minimal processing.
Microwave heating depends on dielectric properties, microwave frequencies, food composition, physical state of water in the food, and product temperature and density. Proper microwave cooking and thawing procedures for ground beef products are needed to ensure food safety. Recent studies showed that the fat content significantly affected the survival of pathogens. The objective of this study was to determine the effect of fat content and temperatures on dielectric properties of ground beef. The dielectric properties were determined using an open-ended, coaxial line with copper conductors, connected to a network analyzer. The relationship among dielectric properties, fat level, and temperature was obtained for 915 MHz and 2450 MHz. Results of the experiment showed that dielectric loss factor and dielectric constant increased with increase in temperature at both frequencies at temperatures below the freezing point. Above the freezing point, dielectric constant decreased with increase in temperature. Dielectric loss factor increased with temperature at 915 MHz. At 2450 MHz, it remained almost constant with varying temperature. Dielectric constant and dielectric loss factor of low-fat ground beef were higher than that of high-fat ground beef. Regression equations were developed for predicting dielectric properties at different temperatures and fat levels.
High pressure processing (HPP) is an alternative mild-technology used in the past decades to sterilize and pasteurize food matrices such as meat and seafood. HPP obeys thermodynamic principles, namely Le Chatelier's law of equilibrium and the isostatic rule, both of which account for microbial inactivation. HPP has the advantage of ensuring reduction of pathogens and spoilage in foods, and preserving the organoleptic characteristics of the product that are compromised in traditional heat treatments. However, high pressure changes the thermodynamic equilibrium of chemical reactions. This is the case of lipid oxidation, in which kinetics is accelerated in the presence of high hydrostatic pressure.
In recent years, there has been increasing focus on the response of lipid components to HPP, especially considering the deleterious outcomes that secondary products of oxidation have on the final product. The objective of this work is to review the literature on the effect of this “mild-technology” in the degradation of lipid fraction of foods. We discuss qualitative and quantitative determinations, as well as the thermodynamic and chemical interpretations underlying the phenomenon.
High pressure processing (HPP) of foods offers a commercially viable and practical alternative to heat processing by allowing food processors to pasteurize foods at or near room temperature. Pressure in combination with moderate temperature also seems to be a promising approach for producing shelf-stable foods. This paper outlines research needs for further advancement of high pressure processing technology. Kinetic models are needed for describing bacterial inactivation under combined pressure-thermal conditions and for microbial process evaluation. Further, identification of suitable surrogate organisms are needed for use as indicator organisms and for process validation studies. More research is needed to evaluate process uniformity at elevated pressure-thermal conditions to facilitate successful introduction of low-acid shelf-stable foods. Combinations of non-thermal technologies with high pressure could reduce the severity of the process pressure requirement. Likewise, processing equipment requires improvements in reliability and line-speed to compete with heat pasteurization lines. More studies are also needed to document the changes in animal and vegetable tissue and nutrient content during pressure processing, from types of packaging, and from storage.
The responses of foods to microwave exposure are usually evaluated only in terms of physicochemical properties, thus undervaluing the importance of DNA in an authentication process by PCR-based methods. In this study, the time effect of microwave heating on some meat physicochemical properties and DNA quality has been investigated.
Cooking loss, instrumental colour, pH, and other physicochemical parameters varied significantly during microwave cooking, reaching the lowest/highest values after 2.5 min of cooking. The exposure of meat to microwaves was found to affect characteristically the quality of extracted DNA (i.e. yield, purity and degradation). PCR products of both mitochondrial and nuclear regions were successfully observed in all samples. However, the band for large fragments became progressively fainter as treatment time increased.
Microwave heating caused physicochemical changes in bovine supraspinatus muscle and influenced characteristically the yield and integrity of the extracted DNA, indicating that an accurate DNA quantification and a rational choice of the genes (i.e. mtDNA versus nDNA, fragment size, etc.) to be amplified are fundamental in an authentication process by PCR-based methods.
The microwave assisted thermal sterilization computer simulation model (MATS-CSM) was developed to improve the previous computer simulation model for the microwave assisted thermal sterilization (MATS) system. Development of the new MATS-CSM included determination of optimum heating time step, evaluation of electromagnetic field distribution and the resulting heating pattern in food, and experimental validation of heating patterns. It was determined that the minimum number of discretization that would not cause immediate divergence of the EM-heat transfer solution was 32 steps corresponding to 97 mm and 5.6 s of displacement and heating time for every step, respectively. Furthermore, this study successfully demonstrated the symmetrical electromagnetic field distribution between top and bottom microwave entry ports and a staggered electric field pattern from one cavity of the MATS to the next. In addition, MATS-CSM confirmed that incorporating heat diffusion in the simulation model reduces the difference in hot spot and cold spot temperature by 65%. It also confirmed that water circulation reduces the edge heating effect, as observed in experiments. The heating pattern generated by MATS-CSM was verified experimentally through a chemical marker method. Based on the percent areal cross section of the weighted average temperature, there were no noticeable differences between the heating zones generated by the MATS-CSM and by the chemical marker method. The percent areal cross section of the cold area 1, cold area 2, and hot area by MATS-CSM were 35%, 25%, and 40%, respectively, and the cold area 1, cold area 2, and hot area by chemical marker method were 35%, 30%, and 35%, respectively.
Convective heat transfer coefficients were evaluated during end-over-end rotation processing of cans filled with liquid and particle mixtures in a pilot-scale, overpressure water-immersion, rotary retort. Two modes of end-over-end agitation were employed, one involving a continuous and the other involving an oscillatory rotation of the cage containing cans. Nylon spheres of diameter 0.025 m were used as test particles and a high temperature bath oil was used as the test liquid. A lumped capacity approach was employed to determine the overall heat transfer coefficient, U, and an inverse heat transfer approach was used to determined the fluid to particle heat transfer coefficient, hfp. Effects of the two modes of rotation (continuous and oscillation) on the associated heat transfer coefficients were evaluated at three speeds (8, 16 and 24 rpm) and three radii of rotation (0,13 and 26 cm). An analysis of variance showed that the effects of rotation speed and mode of rotation on both U and htp were significant (p < 0.05). However, the effect of radius of rotation was significant only with U. These factors also affected the calculated process times for achieving an accumulated lethality (Fo) of 10 min at the particle center and in the can liquid in a similar fashion. In general, U and hfp values associated with continuous rotation were 10-40% higher than those associated with oscillatory rotation.
The effect of high pressure treatments at various temperature combinations on the inactivation of Clostridium botulinum type E spores of strains, Alaska and Beluga in phosphate buffer (0.067 M, pH 7.0) was investigated. No reduction of spores was observed at any pressurization (Maximum = 827 MPa) for temperatures below 35C. At pressurization of 827 MPa for 5 min, log unit reduction of spores increased as temperatures increased from 35 to 55C. An increase in the processing time from 5 to 10 min at a combination of high pressure (827 MPa) and low temperature (40C) resulted in a 5-log reduction of Alaska spores. About 5-log reductions for strains Alaska and Beluga occurred at 50 and 55C, respectively, after processing at pressures of 827 MPa for 5 min.
Effects of Pacific traditional style of cooking in an earth-oven1 on proximate content of chicken, lamb chops, fish, cassava, taro and palusami2 were investigated. Retention of proximates in earth-oven-cooked samples was compared with the retention in microwaved and oven-roasted chicken and lamb chops, microwave-cooked fish, boiled cassava and taro, and steamed-cooked palusami, the nutrient analyses of all of which were conducted during the course of this study. Water content of the samples generally decreased most upon earth-oven cooking. As much as 32.9% moisture was lost from earth-oven-cooked lean of lamb chops. Loss of water from microwave-cooked meat, ranging from 6.6 to 25.8 g/100 g, was second to the moisture loss in earth-oven-cooked meat and the least amount of moisture was lost from the gas-oven roasted meat with the values ranging from 4.4 to 22.2 g/100 g. Retention of protein ranged from 96% to 103% in all samples, the differences being not statistically significant. However, interestingly high retention values of fat were noted in separable lean of lamb chops ranging from 291% to 294%. A simple and logical explanation for this observation is adsorption of fat from separable fat, as it melted during cooking, into the muscle tissue of lamb chops. Retention of over 100% dietary fiber in all foods that had this component in the raw state was noted upon all types of cooking, except in steam-cooked palusami. This implied an increase in this component of food after cooking, whereas starch and sugars generally decreased after cooking.
Minced beef meat was packaged under vacuum, air or oxygen, and pressurized at 10°C for 10 min. L* colour values increased significantly in the range 200–350 MPa, the meat becoming pink, while a* values decreased at 400–500 MPa, the meat becoming grey-brown. Simultaneously, total extractible myoglobin decreased in the range 200–500 MPa, while the proportion of metmyoglobin increased at the expense of oxymyoglobin at 400–500 MPa. Pressurization did not significantly increase the extractibility of heme iron by an acid solution. Packaging of meat under vacuum with an oxygen scavenger partly protected meat colour, since samples processed at 400 MPa became pink, without any change in a* value or metmyoglobin content. Blending chilled minced meat with NaNo2(and NaCl) 18 h before processing at 350–500 MPa afforded a similar protection. Cysteine, ascorbic acid, nicotinamide or nicotinic acid had no protective effects. Meat discoloration through pressure processing may result from (1) a whitening effect in the range 200–350 MPa, due to globin denaturation and/or to heme displacement or release, and (2) oxidation of ferrous myoglobin to ferric metmyoglobin, at or above 400 MPa. Only the latter phenomenon is prevented by total oxygen removal or prior formation of nitrosomyoglobin.
A convenient, ready to consume thermal processed black clam product retaining its natural texture and succulence has been developed. The product developed was vacuum packed in indigenously developed retortable pouch and processed in a still over pressure retort. Time–temperature data was collected during heat processing using an Ellab data recorder cum F0 and cook value integrator. The heat penetration characteristics were determined using formula method. The total process time was 44min with a F0 value of 9 and cook value of 99min. These vacuum packed retort processed samples were rated excellent by the taste panel and remained in good condition even after storage for one year at ambient temperature (28±2°C).
Experimental time–temperature distributions from two different industrial scale retort systems were statistically analysed. The retort temperature was modelled as the sum of a trend value and a residual, with the trend temperatures being simple functions of time. The residuals were modelled using time-series. The resulting impact on the lethality distribution was assessed by calculating the F-value distribution in the centre of cans simulated via a conduction-heating finite element model for 180 simulated temperature histories. Comparing the distributions obtained with those calculated using the actual experimental temperature histories validated the applicability of this approach. The results indicated that the experimental and the modelled average lethalities were statistically similar at 95% confidence. The standard deviation was also similar for the F-value up to the end of holding but larger for the modelled distribution when considering the whole cycle, which was attributed to a correlation between the heating and cooling parameters that was not considered in the model.
For years, high‐pressure processing has been viewed as useful for pasteurizing food while maintaining the quality of fresh food. However, even at moderate pressure, this process is not without effects on food, especially on meat products. These effects are especially important because pressure greater than 400 MPa is generally necessary to achieve efficient microbial inactivation. In this review, recent advances in the understanding of the impacts of high pressure on the overall quality of raw and processed meat are discussed. Many factors, including meat product formulation and processing parameters, can influence the efficiency of high pressure in pasteurizing meat products. It appears that new strategies are applied either (i) to improve the microbial inactivation that results from high pressure while minimizing the adverse effects of high pressure on meat quality or (ii) to take advantage of changes in meat attributes under high pressure. Most of the time, multiple preservation factors or techniques are combined to produce safe, stable, and high‐quality food products. Among the new applications of high‐pressure techniques for meat and meat‐derivative products are their use in combination with temperature manipulation to texturize and pasteurize new meat products simultaneously.
Effects of high-pressure treatment (100MPa to 600MPa) on lipid oxidation and composition of fatty acids in yak body fat at 4°C and 15°C were investigated for up to 20days storage. 400 and 600MPa treatments increase the level of thiobarbituric acid-reactive substances (TBARS) 335% and 400% (p<0.05), respectively. Composition analysis shows that 600MPa treatment induces a lower (p<0.05) percentage of polyunsaturated fatty acids, and C22:6 decreased significantly. A significant decrease in PUFA/SFA and n-6/n-3 PUFA values was observed at the end of storage. Samples treated at the lower pressures gave good sensory acceptability. It is concluded that a higher-pressure treatment is important in catalyzing lipid oxidation and the evolution of fatty acids in pressure-treated yak body fat.
The role of cathepsin D activity in gelation of chicken meat batters (400 MPa/30 min/70 degreesC) heated-under pressure was investigated, using a specific inhibitor, pepstatin, dissolved in dimethyl sulphoxide (DMSO)/acetic acid (9:1 v/v). Thermal treatment (70 degreesC/30 min) produced less thermal inactivation of cathepsin D activity at 400 MPa than at atmospheric pressure. Heating, under pressure conditions, produced gels which were less hard and chewy than those produced at atmospheric pressure. Irrespective of the pressure, the presence of the inhibitor solvent influenced the thermal gelation of meat batters, facilitating the formation of harder, chewier gels. (C) 2002 Elsevier Science Ltd. All rights reserved.
It is well known that spore germination and inactivation can be achieved within a broad temperature and pressure range. The existing literature, however, reports contradictory results concerning the effectiveness of different pressure-temperature combinations and the underlying inactivation mechanism(s). Much of the published kinetic data are prone to error as a result of unstable process conditions or an incomplete investigation of the entire inactivation pathway. Here, we review this field of research, and also discuss an inactivation mechanism of at least two steps and propose an inactivation model based on current data. Further, spore resistance properties and matrix interactions are linked to spore inactivation effectiveness.
The effect of high pressure treatment (HPP) (150 MPa and 300 MPa for 15 min) and cooking on quality of Atlantic salmon based on microbial activity, lipid oxidation, fatty acid profile, colour and texture during 6 days of storage was studied. High pressure and cooking significantly (p < 0.05) reduced microbial growth. The 300 MPa treatment and cooking showed higher L∗ and b∗ values but lower a∗ values for dark muscle compared to control and samples treated at 150 MPa. An increase in pressure resulted in an increase in hardness, gumminess and chewiness parameters, and a decrease in adhesiveness compared to control and cooked samples. Whereas cooking and 150 MPa led to similar oxidation development as control in dark muscle, the 300 MPa treatment effectively reduced the samples susceptibility to oxidation. Fatty acid profile of cooked Atlantic salmon dark muscle showed significantly (p < 0.05) lower amounts of total saturated, n−3 Polyunsaturated fatty acids (PUFA) and n−6 PUFA and significantly (p < 0.05) higher amounts of monoenes than HPP treated samples during the entire storage period. However, the most important finding of this study was that there was no significant (p > 0.05) difference between control and HPP treated samples in terms of total saturated, monoenes, n−3 PUFA and n−6 PUFA fatty acid profile. This demonstrates that HPP is a very mild process in terms of its effect on fatty acids.
The main targets for the pressure induced changes in proteins are those regions primarily stabilised by hydrophobic and electrostatic interactions, since hydrogen bonds are almost pressure insensitive. Thus pressure treated proteins may well have very different structures to their native or heat treated counterparts and as a consequence different functionalities. This concept is used to discuss how pressure can modify the foaming, emulsifying and gelling properties of some food proteins and can also be used to modify the activity of some enzymes of importance in dictating food quality.
A multiphase model based on unsaturated flow in a hygroscopic porous medium, which accounts for the important physical phenomena that take place during thermal treatment of meat, is developed. Frozen meat is considered as a porous solid comprising of water, fat and protein with gas trapped in its pores. As it is heated, water and fat melt, and, are gradually released from the solid protein matrix to the pore space. With further rise in temperature, liquid water evaporates. Since four fluid components (liquid water phase, liquid fat phase, water vapor and air) are present in the pore space, a mass balance equation is written for each component. Local thermal equilibrium assumption leads to one energy balance equation for the whole system. The model is validated for double-sided contact heating of hamburger patties by comparing temperature and moisture profiles with experimental studies. Dominant modes of transport are identified.
Seer fish in curry medium packed in locally manufactured retort pouches, having a three-layer configuration of thickness 12.5 µm polyester/12.5 µm aluminium foil/80 µm cast polypropylene was processed in a steam/air mixture over a pressure retort. About 210 g fish curry, having 110 g fish slices, was packed in a retort pouch of size 17 cm × 15.5 cm, each fitted with a thermocouple. Time–temperature data were collected during heat processing using an Ellab data recorder FO and cook value integrator. The heat penetration characteristics were determined using a mathematical method. The fh value was 25 min with a FO value of 11.5 and cook value of 95 min. These samples remained in good condition for up to 24 months at room temperature. Copyright © 2002 John Wiley & Sons, Ltd.
Optimal variable retort temperature profiles (VRT) for the sterilization of conduction heated foods were calculated using a quasi-Newton multivariable optimization algorithm considering both the maximization of surface quality and the minimization of total process time. When the maximization of surface quality was the objective, an increase up to 20% in quality retention was predicted for optimal VRT profiles as compared to optimal constant retort temperature profiles (CRT). When considering the minimization of total process time, the use of VRT profiles allowed reduction in the total process time of up to 45% while still providing the same surface quality as optimal CRT. Since the results could not be generalized, it was concluded that optimal VRT profiles should be calculated on a case-by-case basis.
The effect on the Warner-Bratzler shear values of post-rigor beef muscles of heat treatments ranging from 40 to 80°C with or without concurrent pressure treatment at 150 MPa have been investigated. For muscles in a stretched condition, a decrease in shear values attributed to changes in the connective tissue was found to occur at a higher temperature in the pressure treated samples than in those not pressure treated. For muscles in a contracted condition, a steep increase in shear values with increase in cooking temperature (attributed to myofibrillar toughening) was prevented by pressure treatment. Instead, a decrease in shear values attributed to changes in connective tissue as found in stretched muscle, was then evident.
Introduction Materials and Methods Results and Discussion Discussion and Conclusions Acknowledgments References
Pressures of the order of 100 MNm—2 applied for 2.5 min or longer to postrigor muscle heated to 40–60°C improved the tenderness of the meat when subsequently cooked. The magnitude of the effect depended on the intensity and duration of pressurization, and the temperature attained by the meat during pressurization. As judged by taste panel assessment and by shear values of the cooked meat, the properties of pressure-heat treated postrigor muscle approximated those of prerigor pressurized muscle. The process is effective in overcoming toughness associated with contracted muscle. It is suggested that the treatment operates on the myofibrillar component of toughness.
Lipid oxidation and colour in pressurised and heated chicken samples were evaluated. In a preliminary test, raw and overcooked (100 °C/60 min) minced chicken thighs were pressurised (500 MPa/50 °C/30 min). Samples were stored at 4 °C in contact with air. Thiobarbituric acid reactive substances (TBARS) were quantified at 1, 6 and 9 days. Pressure induced oxidation in chicken, but overcooking generated many more secondary oxidation compounds. In a second experiment, raw minced chicken thighs were pressurised (500 MPa/−10, 5, 20 and 50 °C/30 and 60 min) or cooked (90 °C/15 min). Samples were vacuum stored at 4 °C. TBARS were measured at 1 and 9 days, whereas colour parameters (L, a, b and ΔE) were determined at 1 day. No differences in TBARS values were observed between untreated and pressurised samples, whereas cooked samples presented the highest values. Pressurisation for 30 and 60 min generated similar TBARS contents. At 9 days, oxidation values did not increase. Pressurisation and cooking induced marked colour changes. Pressurised samples were lighter and less red than untreated ones. Samples pressurised at 50 °C were the palest and, together with cooked samples, presented the lowest a values. Therefore pressurised chicken thigh cannot be marketed as a fresh product but can be incorporated as an ingredient in ready-to-eat meals. Copyright © 2004 Society of Chemical Industry
Cooked turkey breast is particularly susceptible to lipid oxidation-mediated off-flavour development during refrigerated storage. Volatile aroma compounds present in freshly cooked turkey breast muscle after cooling in air and under nitrogen, and also those in air-cooled meat stored for 3 days at 4 °C, were examined using headspace solid phase microextraction (SPME) combined with gas chromatography–mass spectrometry (GC–MS). Odour-port sensory assessment of the separated volatiles was carried out, using a modified form of aroma extract dilution analysis (AEDA). Compared to weakly aromatic nitrogen-cooled turkey breast, the levels of a number of unsaturated carbonyl compounds were much higher in freshly cooked air-cooled samples and showed further large increases in the oxidized chilled meat. Among these, the most potent odour contributors to both fresh and oxidized turkey samples were 1-octen-3-one, (E,E)-2,4-decadienal and (E,Z)-2,6-nonadienal. The concentration of the only moderately potent sulphur-containing compound identified, viz. 2-pentylthiophene, was significantly lower in the oxidized compared to the fresh samples, and gas chromatography–olfactometry (GCO) suggested that this compound made a contribution to the aroma of freshly cooked turkey. Copyright © 2002 John Wiley & Sons, Ltd.
Crude calcium-activated factor (CAF) was prepared from pre-rigor pressurized (PRP) and corresponding control (CON) bovine muscles at 0, 1, and 3 days of postmortem times. Throughout these periods, PRP samples had consistently lower total CAF activity than CON. Yet, it seems probable that PRP caused a transient increase in Ca++ sufficient to activate CAF for a brief period of time because (1) early postmortem, PRP muscle had quantities of a 95,000-dalton component presumably produced by CAF; (2) Z-lines from at-death PRP muscles were highly degraded; (3) very early postmortem storage, the SDS-electrophoretic patterns of PRP myofibrils resembled that of CAF-treated myotibrils. CAF autolysis may account for the low CAF activity observed in PRP muscles at later postmortem storage times.
Variable retort temperature processes (VRT), in which retort temperature is a function of time, were developed for sterilization of Pacific salmon in 307 × 115 steel cans, with objectives of minimizing loss of quality criteria such as surface quality or thiamine, or minimizing process time, all while maintaining constant center-point lethality (F). A finite difference computer model of conduction within a finite cylinder was used to test different temperature-time profiles. Processes were constrained to include steam vent schedules and to exclude temperature decrease during the heating process as well as temperature modulation during cooling, thereby improving compatibility with typical salmon canning facilities. Rho, the fraction of total lethality accumulated at steam-off time, was found to be a function of final unaccomplished temperature, retort temperature, salmon thermal diffusivity and container geometry. The search for favorable processes was aided by Random Centroid Optimization (RCO). Minimum surface cook in constant retort temperature (CRT) processes varied with retort temperature and z of surface quality, but the best VRT process was consistently better than the best CRT process. VRT reduced operator's process time from 64 min to 54 min and maintained equal F0 and surface quality. Thiamine losses were reduced from 19.6% loss by CRT to 16.8% loss by VRT.
Fish curry processed in metal cans is popular in the overseas markets. An important limitation with the use of metal cans is the undesirable taste imparted to the products on storage. Flexible pouches are an ideal alternative to metal cans. Extensive work carried out at Central Institute of Fisheries Technology has been able to identify indigenous pouches, which are as good as imported pouches. This has been done after collecting different types of indigenous and imported flexible pouches, analyzing their composition and conducting detailed studies on their physical and food contact application properties. Two indigenous pouches with composition polyester/ aluminium foil/ cast polypropylene and polyester/ aluminium foil/ cast polypropylene have been selected and got made by indigenous laminators and an imported one with configuration polyester/ aluminium foil/ cast polypropylene were used for further experiment on processing fish curry. Traditional Kerala style mackerel fish curry was processed in the retort pouches of the above configurations. About 220 g fish curry was packed in each pouch . Process requirements were worked out by measuring heat penetration using thermocouples introduced into the pouches. Fish curry processed to a F0 value of 8.43 gave an acceptable product with desired texture and sensory characteristics. The physical properties of the pouches studied showed that the indigenous pouches of the above configurations were good enough to give a shelf life of 1 year at room temperature. The curry remained sterile throughout the storage period at ambient temperature (25–30°C) and retained acceptable sensory characteristics.
To examine the usefulness of measurement of adenosine triphosphate (ATP)-related compounds for estimation of the quality of canned and/or retorted fishes, we investigated the ATP-related compounds, in sashimi (for raw-eating)-grade and for-cooking-grade chub mackerel Scomber japonicus before and after retort process (121 °C for 30 min) by HPLC method. By the deterioration (storage time) and retort process, inosine monophosphate (IMP), an umami-taste compound, was decreased and inosine (HxR), hypoxantine (Hx) and the K-value, an index of fish freshness defined as the ratio of the sum of HxR and Hx to the sum of ATP-related compounds, were increased. By the retorting, the K-values of sashimi-grade, for-cooking-grade and unacceptable-grade meats were increased from 9.9%, 26.6% and 70% to 36%, 46% and 81%, respectively. These results suggest that the measurement of ATP-related compounds in retorted fish products may estimate the freshness in raw materials, the product quality and/or the good manufacture practices.
When compared to thermal and chemical alternatives, high hydrostatic pressure (HHP) processing is the most effective non-thermal technology to process avocados. Herein we report the effects of HHP-processing (600 MPa, 3 min) and storage (40 days, 4 °C) on the stability of avocado paste (Persea americana, cv.Hass) carotenoids. Likewise, the effects of HHP-processing and storage on hydrophilic and lipophilic oxygen radical ab- sorbance capacities (ORAC) of the product were studied. Pressurization induced a significant increase (approx. 56%) in concentrations of total extractable carotenoids. Highest increases for individual carotenoids were observed for neoxanthin-b (513%), followed by !-cryptoxanthin (312%), !-carotene (284%), à-cryptoxanthin (220%), à-carotene (107%), and lutein (40%). Carotenoid levels declined during storage, but at the end of the product's sensory shelf-life were higher than those initially present in unprocessed avocado paste. Interestingly, ORAC-values followed a different trend than carotenoids; they decreased immediately after HHP-processing and increased during storage, therefore indicating that carotenoids appear to be minor contributors to the total antioxidant capacity of the fruit.
Microwave measurements and the dielectric properties of materials are finding increasing application, as new electro-technology is adapted for use in agriculture and food processing industries. The interest in dielectric properties of materials has historically been associated with the design of electrical equipment, where various dielectrics are used for insulating conductors and other components of electric equipment. Although direct heating by microwaves can offer advantages over conventional heat transfer, the different mechanism of energy transfer in microwave heating has led to new processing challenges. This paper is the outcome of an extensive and comprehensive literature review in the area and mainly summarises several microwave processing aspects and its usefulness in understanding the microwave–material interaction and the role of dielectric properties.