Current and future prospects for the use of pulsed electric field in the meat industry

Evaluation of low-temperature ultrasonic marination of pork meat at various frequencies on physicochemical properties, myoglobin levels, and volatile compounds

This study aims to evaluate the pork meat quality after ultrasonic brining at different frequencies, thereby providing a more comprehensive understanding of the effects of ultrasound marination on meat. The texture profile analysis showed that ultrasonic curing at various frequencies significantly improved the textural properties of samples, especially at 26.8 kHz, resulting in a reduction of tenderness, hardness, and chewiness values by 44%, 43%, and 44%, respectively. The cooking loss of samples marinated by ultrasound decreased from 27% without ultrasonic treatment to 22%, indicating a significant improvement in water-holding capacity, while the changes in pH had only a subtle impact on pork quality. Meanwhile, the color of pork became more rosy hue due to decreased L⁎ values and increased a⁎ values, which was mainly attributed to an elevated proportion of oxymyoglobin and reduced metmyoglobin content. Additionally, ultrasonic marination did not exert a negative impact on the oxidation of pork protein and lipids. After roasting, samples marinated by ultrasound exhibited a significantly higher abundance of volatile flavor compounds compared to static marinated meat (with an increase of 16 flavor substances) and fresh pork (with an increase of 24 flavor substances), demonstrating the efficacy of ultrasonic marination in enhancing the overall flavor and taste profile of pork. Consequently, the application of ultrasonic technology holds great potential for the "home kitchen type" rapid marination.

The one-humped camel: The animal of future, potential alternative red meat, technological suitability and future perspectives

The 2020 world population data sheet indicates that world population is projected to increase from 7.8 billion in 2020 to 9.9 billion by 2050 (Increase of more than 25%). Due to the expected growth in human population, the demand for meats that could improve health status and provide therapeutic benefits is also projected to rise. The dromedary also known as the Arabian camel, or one-humped camel ( Camelus dromedarius), a pseudo ruminant adapted to arid climates, has physiological, biological and metabolic characteristics which give it a legendary reputation for surviving in the extreme conditions of desert environments considered restrictive for other ruminants. Camel meat is an ethnic food consumed across the arid regions of Middle East, North-East Africa, Australia and China. For these medicinal and nutritional benefits, camel meat can be a great option for sustainable meat worldwide supply. A considerable amount of literature has been published on technological aspects and quality properties of beef, lamb and pork but the information available on the technological aspects of the meat of the one humped camel is very limited. Camels are usually raised in less developed countries and their meat is as nutritionally good as any other traditional meat source. Its quality also depends on the breed, sex, age, breeding conditions and type of muscle consumed. A compilation of existing literature related to new technological advances in packaging, shelf-life and quality of camel meat has not been reviewed to the best of our knowledge. Therefore, this review attempts to explore the nutritional composition, health benefits of camel meat, as well as various technological and processing interventions to improve its quality and consumer acceptance. This review will be helpful for camel sector and highlight the potential for global marketability of camel meat and to generate value added products.

Evaluation of ultrasound and pulsed electric field combinations on the cooking Losses, texture Profile, and Taste-Related amino acids of chicken breast meat

The search to improve the quality of meat while maintaining its nutritional value and flavor profile has driven the investigation of emerging clean-label non-thermal technologies in the field of meat processing. Ultrasound (US) and pulsed electric field (PEF) treatments have emerged as promising tools for producing high-quality meat products. This study investigated the combined effects of ultrasound and PEF on chicken breast meat quality, focusing on cooking loss, texture, and taste-related amino acids. Ultrasound (24.5 kHz, 300 W, 10 min) combined with PEF for 30 s (1.6, 3.3, and 5.0 kV/cm as US + PEF 1, US + PEF 3, and US + PEF 5, respectively) significantly reduced cooking losses (up to 28.78 %), potentially improving the product yield. Although US + PEF significantly (p < 0.05) affected pH, particularly at a higher PEF intensity (5 kV/cm), the overall color appearance of the treated meat remained unchanged. The combined treatments resulted in a tenderizing effect and decreased meat hardness, adhesiveness, and chewiness. Interestingly, US + PEF with increasing PEF intensity (1.6 to 5.0 kV/cm) led to a gradual increase in taste-related amino acids (aspartic acid, glutamic acid, etc.), potentially enhancing flavor. FTIR spectra revealed alterations in protein and lipid structures following treatment, suggesting potential modifications in meat quality. Scanning electron microscopy (SEM) revealed significant changes in the texture and structure of US + PEF-treated meat, depicting structural disruptions. Furthermore, Pearson's correlation analysis and principal component analysis (PCA) revealed a clear relationship between the physicochemical characteristics, free amino acids, color, and texture attributes of chicken meat. By optimizing treatment parameters, US + PEF could offer a novel approach to improve chicken breast meat quality.

Diversified Techniques for Restructuring Meat Protein-Derived Products and Analogues

Accompanied by the rapid growth of the global population and increasing public awareness of protein-rich foods, the market demand for protein-derived products is booming. Utilizing available technologies to make full use of meat by-products, such as scraps, trimmings, etc., to produce restructured meat products and explore emerging proteins to produce meat analogues can be conducive to alleviating the pressure on supply ends of the market. The present review summarizes diversified techniques (such as high-pressure processing, ultrasonic treatment, edible polysaccharides modification, enzymatic restructuring, etc.) that have been involved in restructuring meat protein-derived products as well as preparing meat analogues identified so far and classifying them into three main categories (physical, chemical and enzymatic). The target systems, processing conditions, effects, advantages, etc., of the included techniques, are comprehensively and systemically summarized and discussed, and their existing problems or developing trends are also briefly prospected. It can be concluded that a better quality of restructured products can be obtained by the combination of different restructuring technologies. This review provides a valuable reference both for the research and industrial production of restructured meat protein-derived products and analogues.

Electrical Stimulation Induces Activation of Mitochondrial Apoptotic Pathway and Down-Regulates Heat Shock Proteins in Pork: An Innovative Strategy for Enhancing the Ripening Process and Quality of Dry-Cured Loin Ham

A fundamental regulatory framework to elucidate the role of electrical stimulation (ES) in reducing long production cycles, enhancing protein utilization, and boosting product quality of dry-cured ham is essential. However, how mitochondria and enzymes in meat fibers are altered by ES during post-processing, curing, and fermentation procedures remains elusive. This study sought to explore the impact of ES on the regulation of heat shock proteins (HSP27, HSP70), apoptotic pathways, and subsequent influences on dry-cured pork loin quality. The gathered data validated the hypothesis that ES notably escalates mitochondrial oxidative stress and accelerates mitochondrial degradation along the ripening process. The proapoptotic response in ES-treated samples was increased by 120.7%, with a cellular apoptosis rate 5-fold higher than that in control samples. This mitochondrial degradation is marked by increased ratios of Bax/Bcl-2 protein along the time course, indicating that apoptosis could contribute to the dry-cured ham processing. ES was shown to further down-regulate HSP27 and HSP70, establishing a direct correlation with the activation of mitochondrial apoptosis pathways, accompanied by dry-cured ham quality improvements. The findings show that ES plays a crucial role in facilitating the ripening of dry-cured ham by inducing mitochondrial apoptosis to reduce HSP expression. This knowledge not only explains the fundamental mechanisms behind myofibril degradation in dry-cured ham production but also offers a promising approach to enhance quality and consistency.

Effect of pulsed electric field (PEF) on NaCl diffusion in beef and consequence on meat quality

The impact of various field strength (2, 3, 4 kV/cm) and treatment time (60s and 90s) combinations on NaCl content and diffusion coefficient of beef were evaluated in the current study. Weight change, water content, water holding capacity, and texture of beef after brining were also explored. The results demonstrated pulsed electric field (PEF) pre-treatment significantly increased NaCl uptake when the brining time was 150 min (P < 0.05). The maximum NaCl content increased by 19.50% and the diffusion coefficient increased by 58.50%. Relatively mild PEF (60s) could improve beef qualities, but longer treatment time (90s) was detrimental to these qualities. Meanwhile, more complete myofibrillar structure and lower lipid oxidation extent were observed in the samples treated by PEF, contributing to the higher a* values. In conclusion, short processing time (60s) and high field strength (4 kV/cm) treatment is a potential strategy for meat brining acceleration and quality improvement in practical industrial production.

A Comprehensive Review of Cured Meat Products in the Irish Market: Opportunities for Reformulation and Processing

Cured meat products constitute one of the meat categories commonly consumed in Ireland and has been part of the Irish cuisine and diet for many years. Ham, gammon, and bacon are some of the products that involve curing as part of the traditional processing methods. Common among these products are high levels of salt and the addition of nitrites. These products undergo processing treatments to create variety, preserve shelf-life, and develop their unique quality and safety characteristics. However, consumers are becoming more conscious of the level of processing involved in these products, and the effects of some components and ingredients might be perceived as unhealthy. Meat product developers have been exploring ways to reduce the amount of ingredients such as salt, saturated fat, and chemical preservatives (e.g., nitrites), which are linked to health concerns. This is a challenging task as these ingredients play an important techno-functional role in the products' quality, safety, and identity. While innovative processing techniques are being introduced and progress has been made in reformulation and packaging technologies, much is still unknown, especially regarding the applicability of many of the proposed interventions to a wide range of meat products and their sustainability at the industrial scale.

Novel NaCl reduction technologies for dry-cured meat products and their mechanisms: A comprehensive review

Sodium chloride (NaCl) confers a unique flavor and quality in meat products, however, due to growing concerns about the adverse effects of excessive NaCl consumption, how to reduce NaCl content while ensuring quality and safety has become a research hotspot in this field. This review mainly discusses the role of NaCl in dry-cured meat, as well as novel salt-reducing substances that can substitute for the effects of NaCl to achieve sodium reduction objectives. New technologies, such as vacuum curing, ultrahigh pressure curing, ultrasonic curing, pulsed electric field curing, and gamma irradiation, to facilitate the development of low-sodium products are also introduced. The majority of current salt reduction technologies function to enhance salt diffusion and decrease curing time, resulting in a decrease in NaCl content. Notably, future studies should focus on implementing multiple strategies to compensate for the deficiencies in flavor and safety caused by NaCl reduction.

Food Processing and Nutrition Strategies for Improving the Health of Elderly People with Dysphagia: A Review of Recent Developments

Dysphagia, or swallowing difficulty, is a common morbidity affecting 10% to 33% of the elderly population. Individuals with dysphagia can experience appetite, reduction, weight loss, and malnutrition as well as even aspiration, dehydration, and long-term healthcare issues. However, current therapies to treat dysphagia can routinely cause discomfort and pain to patients. To prevent these risks, a non-traumatic and effective treatment of diet modification for safe chewing and swallowing is urgently needed for the elderly. This review mainly summarizes the chewing and swallowing changes in the elderly, as well as important risk factors and potential consequences of dysphagia. In addition, three texture-modified food processing strategies to prepare special foods for the aged, as well as the current statuses and future trends of such foods, are discussed. Nonthermal food technologies, gelation, and 3D printing techniques have been developed to prepare soft, moist, and palatable texture-modified foods for chewing and swallowing safety in elderly individuals. In addition, flavor enhancement and nutrition enrichment are also considered to compensate for the loss of sensory experience and nutrients. Given the trend of population aging, multidisciplinary cooperation for dysphagia management should be a top priority.

Effect of sodium salt on meat products and reduction sodium strategies - A review

Sodium salt is one of the important additives in food processing. However, excessive intake of sodium salt may cause a series of cardiovascular diseases. Nowadays, sodium intake in most countries is higher than the World Health Organization recommends maximum consumption (5 g/d). 20% of the sodium intake in diets comes from meat products. Therefore, reducing the content of sodium salt in meat products and developing sodium salt-reduction meat products have attracted more and more attention for consumers. In this paper, the roles of sodium salt in meat product processing were reviewed. At the same time, sodium salt reduction strategies and existing problems were summarized and discussed. Multiple factors need to be considered to improve the salt-reduction meat product's quality. Relying on a single technology has a narrow application area, and it is difficult to achieve salt reduction. Therefore, a combination of multiple strategies could obtain a more ideal effect.

Insights into application progress of seafood processing technologies and their implications on flavor: a review

Seafood tends to be highly vulnerable to spoilage and deterioration due to biochemical reactions and microbial contaminations, which requires appropriate processing technologies to improve or maintain its quality. Flavor, as an indispensable aspect reflecting the quality profile of seafood and influencing the final choice of consumers, is closely related to the processing technologies adopted. This review gives updated information on traditional and emerging processing technologies used in seafood processing and their implications on flavor. Traditional processing technologies, especially thermal treatment, effectively deactivate microorganisms to enhance seafood safety and prolong its shelf life. Nonetheless, these methods come with limitations, including reduced processing efficiency, increased energy consumption, and alterations in flavor, color, and texture due to overheating. Emerging processing technologies like microwave heating, infrared heating, high pressure processing, cold plasma, pulsed electric field, and ultrasound show alternative effects to traditional technologies. In addition to deactivating microorganisms and extending shelf life, these technologies can also safeguard the sensory quality of seafood. This review discusses emerging processing technologies in seafood and covers their principles, applications, developments, advantages, and limitations. In addition, this review examines the potential synergies that can arise from combining certain processing technologies in seafood processing.

Pulsed electric field promotes the growth metabolism of aerobic denitrifying bacteria Pseudomonas putida W207-14 by improving cell membrane permeability

The purpose of this study was to explore the stimulation mechanism of low pulsed electric field (PEF) strength treatment to promote the growth metabolism of aerobic denitrifying bacteria Pseudomonas putida W207-14. The results indicated that compared with the control group, the strain W207-14 treated with PEF entered the logarithmic growth phase 5 h earlier, the growth time to reached the maximum cell optical density at 600 nm (OD600) of 1.935 ± 0.04 was only 24 h, which shortened by half. With the reduction of growth time, the metabolic rate of the strain increased significantly, in which the removal efficiency of COD, NO₃^--N and TN was 97.67 ± 1.12%, 90.34 ± 0.73% and 90.13 ± 0.10% in 24 h, respectively. The maximum nitrate removal rate increased from 3.49 mg/L/h to 7.53 mg/L/h. A large number of cells with simultaneous cell membrane damage and high physiological activity were observed by flow cytometry (FCM) in combination with fluorescence staining analysis, which confirmed the reversible electroporation on the cell membrane of strain W207-14 treated with PEF. Transcriptomic analysis indicated that PEF activated the highly significant differential expression of membrane porin (opdB, opdC, and oprB) and cytochrome oxidoreductase related genes (ccoP, ccoN, cioA and cioB) on the cell membrane, which promoted the transport of nutrients through the cell membrane and electron transfer during aerobic respiration and provided an explanation for the possible mechanism of PEF promoting the growth metabolism of strain W207-14 at the micro level. These results lay a foundation for the practical application of PEF enhanced aerobic denitrification technology.

Food matrix design can influence the antimicrobial activity in the food systems: A narrative review

Antimicrobial agents are safe preservatives having the ability to protect foods from microbial spoilage and extend their shelf life. Many factors, including antimicrobials' chemical features, storage environments, delivery methods, and diffusion in foods, can affect their antimicrobial activities. The physical-chemical characteristics of the food itself play an important role in determining the efficacy of antimicrobial agents in foods; however the mechanisms behind it have not been fully explored. This review provides new insights and comprehensive knowledge regarding the impacts of the food matrix, including the food components and food (micro)structures, on the activities of antimicrobial agents. Studies of the last 10 years regarding the influences of the food structure on the effects of antimicrobial agents against the microorganisms' growth were summarized. The mechanisms underpinning the loss of the antimicrobial agents' activity in foods are proposed. Finally, some strategies/technologies to improve the protection of antimicrobial agents in specific food categories are discussed.

Effect of Pulsed Electric Field on the Chicken Meat Quality and Taste-Related Amino Acid Stability: Flavor Simulation

Meat contains several amino acids related to taste, which have a significant impact on the overall acceptability of consumers. A number of volatile compounds have been studied in relation to meat flavor, but amino acids have not been fully explored in relation to the taste of raw or cooked meat. It would be interesting to find any changes in physicochemical characteristics, especially the level of taste-active compounds and flavor content during non-thermal processing such as pulsed electric fields (PEF), for commercial reasons. The effect of PEF at low intensity (LPEF; 1 kV/cm) and comparatively high intensity (HPEF; 3 kV/cm) with different pulse numbers (25, 50, and 100) was investigated on the physicochemical characteristics of chicken breast, including the free amino acid content (related to umami, sweet, bitter, or fresh pleasant taste). PEF is regarded as a "nonthermal" technology; however, HPEF induces moderate temperature rises as it increases with the treatment intensity (i.e., electric field strength and pulse number). The pH, shear force, and cook loss (%) of the LPEF and untreated samples were not affected by the treatments, but the shear force of the LPEF and untreated samples was lower than that of HPEF groups that showed PEF-induced slight structural modifications resulting in a more porous cell. In the case of color parameters, the lightness of meat (L*) was significantly higher with treatment intensity, whereas both a* and b* were unaffected by the PEF treatments. Moreover, PEF treatment significantly (p < 0.05) affected umami-related free amino acids (FAAs; glutamic acid and aspartic acid) and leucine and valine, which are precursors of flavor compounds. However, PEF decreases the level of bitter taste contributing FAAs such as lysine and tyrosine, which may prevent the formation of fermented flavors. In conclusion, both PEF treatments (LPEF and HPEF) did not adversely impact the physicochemical quality of chicken breast.

The potential of antifungal peptide Sesquin as natural food preservative

Sesquin is a wide spectrum antimicrobial peptide displaying a remarkable activity on fungi. Contrarily to most antimicrobial peptides, it presents an overall negative charge. In the present study, we elucidate the molecular basis of its mode of action towards biomimetic membranes by NMR and MD experiments. While a specific recognition of phosphatidylethanolamine (PE) might explain its activity in a variety of different organisms (including bacteria), a further interaction with ergosterol accounts for its strong antifungal activity. NMR data reveal a charge gradient along its amide protons allowing the peptide to reach the membrane phosphate groups despite its negative charge. Subsequently, the peptide gets structured inside the bilayer, reducing its order. MD simulations predict that its activity is retained in conditions commonly used for food preservation: low temperatures, high pressure, or the presence of electric field pulses, making Sesquin a good candidate as food preservative.

Investigation of Pulsed Electric Field Conditions at Low Field Strength for the Tenderisation of Beef Topside

Tenderness is the most critical eating quality trait of meat, and consequently, processing interventions for meat tenderisation have significant economic relevance. The objective of this study was to investigate pulsed electric field (PEF) conditions for the tenderisation of beef topside. The PEF settings included combinations of three field strengths (0.25, 0.50 and 1.00 kV/cm), two frequencies (20 and 100 Hz) and three treatment times (10, 30 and 50 ms). The effect of PEF on meat quality parameters (pH, drip loss, shear force, cook loss and colour) immediately after treatment and after storage (1 and 14 days at 4 °C) was evaluated. PEF did not affect meat tenderness after 1 day of chilled storage but resulted in a 5–10% reduction in the shear force in some cases (0.25–0.5 kV/cm) compared to the untreated control after 14 days of storage. Other quality traits (cook loss and colour) were not impaired. Thus, we concluded that PEF technology is a possible intervention to improve meat tenderness of beef topside after 2 weeks of storage.

Post-Harvest Strategies to Improve Tenderness of Underutilized Mature Beef: A Review

Beef muscles from mature cows and bulls, especially those originating from the extremities of the carcass, are considered as underutilized due to unsatisfactory palatability. However, beef from culled animals comprises a substantial proportion of the total slaughter in the US and globally. Modern consumers typically favor cuts suitable for fast, dry-heat cookery, thereby creating challenges for the industry to market inherently tough muscles. In general, cull cow beef would be categorized as having a lower extent of postmortem proteolysis compared to youthful carcasses, coupled with a high amount of background toughness. The extent of cross-linking and resulting insolubility of intramuscular connective tissues typically serves as the limiting factor for tenderness development of mature beef. Thus, numerous post-harvest strategies have been developed to improve the quality and palatability attributes, often aimed at overcoming deficiencies in tenderness through enhancing the degradation of myofibrillar and stromal proteins or physically disrupting the tissue structure. The aim of this review is to highlight existing and recent innovations in the field that have been demonstrated as effective to enhance the tenderness and palatability traits of mature beef during the chilling and postmortem aging processes, as well as the use of physical interventions and enhancement.

Metabolic, proteomic and microbial changes postmortem and during beef aging

The purpose of this review is to provide an overview of the current knowledge about proteomic and metabolic changes in beef, the microbiological alteration postmortem and during aging, and observe the influence on beef quality parameters, such as tenderness, taste and flavor. This review will also focus on the different aging types (wet- and dry-aging), the aging or postmortem time of beef and their effect on the proteome and metabolome of beef. The Ca2+ homeostasis and adenosine 5'-triphosphate breakdown are the main reactions in the pre-rigor phase. After rigor mortis, the enzymatic degradation of connective tissues and breakdown of energy metabolism dominate molecular changes in beef. Important metabolic processes leading to the formation of saccharides, nucleotides, organic acids (e.g. lactic acid), creatine and fatty acids are considered in this context as possible flavor precursors or formers of beef flavor and taste. Flavor precursors are substrates for lipid oxidation, Strecker degradation and Maillard reaction during cooking or roasting. The findings presented should serve as a basis for a better understanding of beef aging and its molecular effects and are intended to contribute to meeting the challenges of improving beef quality.

Comprehensive Review on Banana Fruit Allergy: Pathogenesis, Diagnosis, Management, and Potential Modification of Allergens through Food Processing

The pulp of the banana fruit is rich in bioactive compounds like dietary fibers, low glycemic carbohydrates, natural sugars, vitamins, minerals and antioxidants. These beneficial compounds are responsible for the proper functioning of immune system and enhance prevention against various deadly diseases like cancer, diabetes and heart diseases. Despite having, positive effects, the fruit are recognized as an important source for causing allergy to 0.6% of people in general population and up to 67 and 46% for people with asthma or atopic dermatitis. Fruit allergy is one of the most common food allergies witnessed worldwide. Banana fruit allergy results from the abnormal immune response to the banana proteins soon after its consumption. Symptoms range from oral allergy syndrome (OAS) to the life-threatening anaphylaxis. IgE reactivity of banana is associated with different proteins of which six proteins have been identified as major allergens, viz., Mus a1 (Profilin-actin binding protein), Mus a 2 (Class 1 chitinase), Mus a 3 (Nonspecific lipid transfer protein), Mus a 4 (Thaumatin like protein), Mus a 5 (Beta 1,3 glucanase) and Mus a 6 (Ascorbate peroxidase). This review focuses on pathogenesis, clinical features, diagnosis, and different food processing methods to mitigate the allergenicity of banana fruit.

Changes in Physico-Chemical and Storage Properties of Dry-Aged Beef Loin Using Electric Field Refrigeration System

The aim of this study is to establish the dry aging period of beef loin in an electric field refrigeration system. Beef loins (Korea quality grade 2) were dry aged at 0, −1, and −2 °C temperature in an electric field refrigeration system (air velocity, 5 ± 2 m/s) and aging stopped as the value of TPC reached 7 log CFU/g. Samples were examined by aging yield, trimming yield, pH, color, water holding capacity (WHC), cooking yield, shear force, total plate count (TPC), 2-thiobarbituric acid reactive substances (TBARS), and volatile basic nitrogen (VBN). The results for aging yield, trimming yield, redness, yellowness, and chroma decreased with increasing the dry aging period. Contrariwise, those for pH, lightness, hue angle, WHC, and cooking yield increased with the dry aging period. In shear force, the lowest value occurred at four weeks at all temperatures. The results for TPC, TBARS, and VBN increased with aging period, and VBN at 6 weeks at 0 °C and 9 weeks at −1 °C exceed the standard value (20 mg/100 g), while dry aging temperature had an effect on physico-chemical and storage properties by lower temperatures showed slower progress. Therefore, dry aging on an electric field refrigerate system can be used until 4 weeks at 0 °C, 8 weeks at −1 °C, and 10 weeks at −2 °C. However, considering physico-chemical properties, 4 weeks at every temperature is suitable for manufacturing soft dry-aged beef loin.

Recent advances in the development of healthier meat products

Meat products are an excellent source of high biological value proteins, in addition to the high content of minerals, vitamins, and bioactive compounds. However, meat products contain compounds that can cause a variety of adverse health effects and pose a serious health threat to humans. In this sense, this chapter will address recent strategies to assist in the development of healthier meat products. The main advances about the reduction of sodium and animal fat in meat products will be presented. In addition, strategies to make the lipid profile of meat products more nutritionally advantageous for human health will also be discussed. Finally, the reduction of substances of safety concern in meat products will be addressed, including phosphates, nitrites, polycyclic aromatic hydrocarbons, heterocyclic aromatic amines, as well as products from lipid and protein oxidation.

Effects of an Electric Field on the Conformational Transition of the Protein: Pulsed and Oscillating Electric Fields with Different Frequencies

The effect of pulsed and oscillating electric fields with different frequencies on the conformational properties of all-α proteins was investigated by molecular dynamics simulations. The root mean square deviation, the root mean square fluctuation, the dipole moment distribution, and the secondary structure analysis were used to assess the protein samples’ structural characteristics. In the simulation, we found that the higher frequency of the electric field influences the rapid response to the secondary structural transitions. However, the conformational changes measured by RMSD are diminished by applying the electrical field with a higher frequency. During the dipole moment analysis, we found that the magnitude and frequency of the dipole moment was directly related to the strength and frequency of the external electric field. In terms of the type of electric fields, we found that the average values of RMSD and RMSF of whole molecular protein are larger when the protein is exposed in the pulsed electric field. Concerning the typical sample 1BBL, the secondary structure analysis showed that two alpha-helix segments both transit to turns or random coils almost simultaneously when it is exposed in a pulsed electric field. Meanwhile, two segments present the different characteristic times when the transition occurs in the condition of an oscillating electric field. This study also demonstrated that the protein with fewer charged residues or more residues in forming α-helical structures display the higher conformational stability. These conclusions, achieved using MD simulations, provide a theoretical understanding of the effect of the frequency and expression form of external electric fields on the conformational changes of the all-α proteins with charged residues and the guidance for anticipative applications.

Novel Techniques for Microbiological Safety in Meat and Fish Industries

The consumer tendency towards convenient, minimally processed meat items has placed extreme pressure on processors to certify the safety of meat or meat products without compromising the quality of product and to meet consumer’s demand. This has prompted difficulties in creating and carrying out novel processing advancements, as the utilization of more up-to-date innovations may influence customer decisions and assessments of meat and meat products. Novel advances received by the fish and meat industries for controlling food-borne microbes of huge potential general wellbeing concern, gaps in the advancements, and the requirement for improving technologies that have been demonstrated to be effective in research settings or at the pilot scale shall be discussed. Novel preparing advancements in the meat industries warrant microbiological approval before being named as industrially suitable alternatives and authorizing infra-structural changes. This miniature review presents the novel techniques for the microbiological safety of meat products, including both thermal and non-thermal methods. These technologies are being successfully implemented and rationalized in subsisting processing surroundings.

Innovative Non-Thermal Technologies for Recovery and Valorization of Value-Added Products from Crustacean Processing By-Products-An Opportunity for a Circular Economy Approach

The crustacean processing industry has experienced significant growth over recent decades resulting in the production of a great number of by-products. Crustacean by-products contain several valuable components such as proteins, lipids, and carotenoids, especially astaxanthin and chitin. When isolated, these valuable compounds are characterized by bioactivities such as anti-microbial, antioxidant, and anti-cancer ones, and that could be used as nutraceutical ingredients or additives in the food, pharmaceutical, and cosmetic industries. Different innovative non-thermal technologies have appeared as promising, safe, and efficient tools to recover these valuable compounds. This review aims at providing a summary of the main compounds that can be extracted from crustacean by-products, and of the results obtained by applying the main innovative non-thermal processes for recovering such high-value products. Moreover, from the perspective of the circular economy approach, specific case studies on some current applications of the recovered compounds in the seafood industry are presented. The extraction of valuable components from crustacean by-products, combined with the development of novel technological strategies aimed at their recovery and purification, will allow for important results related to the long-term sustainability of the seafood industry to be obtained. Furthermore, the reuse of extracted components in seafood products is an interesting strategy to increase the value of the seafood sector overall. However, to date, there are limited industrial applications for this promising approach.

Meat tenderness: advances in biology, biochemistry, molecular mechanisms and new technologies

Meat tenderness is an important quality trait critical to consumer acceptance, and determines satisfaction, repeat purchase and willingness-to-pay premium prices. Recent advances in tenderness research from a variety of perspectives are presented. Our understanding of molecular factors influencing tenderization are discussed in relation to glycolysis, calcium release, protease activation, apoptosis and heat shock proteins, the use of proteomic analysis for monitoring changes, proteomic biomarkers and oxidative/nitrosative stress. Each of these structural, metabolic and molecular determinants of meat tenderness are then discussed in greater detail in relation to animal variation, postmortem influences, and changes during cooking, with a focus on recent advances. Innovations in postmortem technologies and enzymes for meat tenderization are discussed including their potential commercial application. Continued success of the meat industry relies on ongoing advances in our understanding, and in industry innovation. The recent advances in fundamental and applied research on meat tenderness in relation to the various sectors of the supply chain will enable such innovation.

Effect of processing technologies on the digestibility of egg proteins

Egg and egg products are a rich source of highly bioavailable animal proteins. Several processing technologies can affect the structural and functional properties of these proteins differently and can influence their fate inside the gastrointestinal tract. The present review examines some of the processing technologies for improving egg protein digestibility and discusses how different processing conditions affect the digestibility of egg proteins under gastrointestinal digestion environments. To provide up-to-date information, most of the studies included in this review have been published in the last 5 years on different aspects of egg protein digestibility. Digestibility of egg proteins can be improved by employing some processing technologies that are able to improve the susceptibility of egg proteins to gastrointestinal proteases. Processing technologies, such as pulsed electric field, high-pressure, and ultrasound, can induce conformational and microstructural changes that lead to unfolding of the polypeptides and expose active sites for further interactions. These changes can enhance the accessibility of digestive proteases to cleavage sites. Some of these technologies may inactivate some egg proteins that are enzyme inhibitors, such as trypsin inhibitors. The underlying mechanisms of how different technologies mediate the egg protein digestibility have been discussed in detail. The proteolysis patterns and digestibility of the processed egg proteins are not always predictable and depends on the processing conditions. Empirical input is required to tailor the optimization of processing conditions for favorable effects on protein digestibility.

Techniques for postmortem tenderisation in meat processing: effectiveness, application and possible mechanisms

Abstract

Developing efficient and promising tenderising techniques for postmortem meat is a heavily researched topic among meat scientists as consumers are willing to pay more for guaranteed tender meat. However, emerging tenderising techniques are not broadly used in the meat industry and, to some degree, are controversial due to lack of theoretical support. Thus, understanding the mechanisms involved in postmortem tenderisation is essential. This article first provides an overview of the relationship of ageing tenderisation and calpain system, as well as proteomics applied to identify protein biomarkers characterizing tenderness. In general, the ageing tenderisation is mediated by multiple biochemical activities, and it can exhibit better palatability and commercial benefit by combining other interventions. The calpain system plays a key role in ageing tenderisation functions by rupturing myofibrils and regulating proteolysis, glycolysis, apoptosis and metabolic modification. Additionally, tenderising techniques from different aspects including exogenous enzymes, chemistry, physics and the combined methods are discussed in depth. Particularly, innovation of home cooking could be recommended to prepare relatively tender meat due to its convenience and ease of operation by consumers. Furthermore, the combined interventions provide better performance in controlled tenderness. Finally, future trends in developing new tenderising techniques, and applied consideration in the meat processing industry are proposed in order to improve meat quality with higher economical value.

Graphical abstract

Whey allergens: Influence of nonthermal processing treatments and their detection methods

Whey and its components are recognized as value-added ingredients in infant formulas, beverages, sports nutritious foods, and other food products. Whey offers opportunities for the food industrial sector to develop functional foods with potential health benefits due to its unique physiological and functional attributes. Despite all the above importance, the consumption of whey protein (WP) can trigger hypersensitive reactions and is a constant threat for sensitive individuals. Although avoiding such food products is the most successful approach, there is still a chance of incorrect labeling and cross-contamination during food processing. As whey allergens in food products are cross-reactive, the phenomenon of homologous milk proteins of various species may escalate to a more serious problem. In this review, nonthermal processing technologies used to prevent and eliminate WP allergies are presented and discussed in detail. These processing technologies can either enhance or mitigate the impact of potential allergenicity. Therefore, the development of highly precise analytical technologies to detect and quantify the existence of whey allergens is of considerable importance. The present review is an attempt to cover all the updated approaches used for the detection of whey allergens in processed food products. Immunological and DNA-based assays are generally used for detecting allergenic proteins in processed food products. In addition, mass spectrometry is also employed as a preliminary technique for detection. We also highlighted the latest improvements in allergen detection toward biosensing strategies particularly immunosensors and aptasensors.

Endogenous Proteolytic Systems and Meat Tenderness: Influence of Post-Mortem Storage and Processing

Meat proteolytic systems play a crucial role in meat tenderisation. Understanding the effects of processing technologies and post-mortem storage conditions on these systems is important due to their crucial role in determining the quality characteristics of meat and meat products. It has recently been proposed that tenderisation occurs due to the synergistic action of numerous endogenous proteolytic systems. There is strong evidence suggesting the importance of μ-calpain during the initial post-mortem aging phase, while m-calpain may have a role during long-term aging. The caspase proteolytic system is also a candidate for cell degradation in the initial stages of conversion of muscle to meat. The role of cathepsins, which are found in the lysosomes, in post-mortem aging is controversial. Lysosomes need to be ruptured, through aging, or other forms of processing to release cathepsins into the cytosol for participation in proteolysis. A combination of optimum storage conditions along with suitable processing may accelerate protease activity within meat, which can potentially lead to improved meat tenderness. Processing technologies such as high pressure, ultrasound, and shockwave processing have been reported to disrupt muscle structure, which can facilitate proteolysis and potentially enhance the aging process. This paper reviews the recent literature on the impacts of processing technologies along with post-mortem storage conditions on the activities of endogenous proteases in meat. The information provided in the review may be helpful in selecting optimum post-mortem meat storage and processing conditions to achieve improved muscle tenderness within shorter aging and cooking times.

Revisiting Non-Thermal Food Processing and Preservation Methods-Action Mechanisms, Pros and Cons: A Technological Update (2016-2021)

The push for non-thermal food processing methods has emerged due to the challenges associated with thermal food processing methods, for instance, high operational costs and alteration of food nutrient components. Non-thermal food processing involves methods where the food materials receive microbiological inactivation without or with little direct application of heat. Besides being well established in scientific literature, research into non-thermal food processing technologies are constantly on the rise as applied to a wide range of food products. Due to such remarkable progress by scientists and researchers, there is need for continuous synthesis of relevant scientific literature for the benefit of all actors in the agro-food value chain, most importantly the food processors, and to supplement existing information. This review, therefore, aimed to provide a technological update on some selected non-thermal food processing methods specifically focused on their operational mechanisms, their effectiveness in preserving various kinds of foods, as revealed by their pros (merits) and cons (demerits). Specifically, pulsed electric field, pulsed light, ultraviolet radiation, high-pressure processing, non-thermal (cold) plasma, ozone treatment, ionizing radiation, and ultrasound were considered. What defines these techniques, their ability to exhibit limited changes in the sensory attributes of food, retain the food nutrient contents, ensure food safety, extend shelf-life, and being eco-friendly were highlighted. Rationalizing the process mechanisms about these specific non-thermal technologies alongside consumer education can help raise awareness prior to any design considerations, improvement of cost-effectiveness, and scaling-up their capacity for industrial-level applications.

Combination of Natural Compounds With Novel Non-thermal Technologies for Poultry Products: A Review

Ensuring safe, fresh, and healthy food across the shelf life of a commodity is an ongoing challenge, with the driver to minimize chemical additives and their residues in the food processing chain. High-value fresh protein products such as poultry meat are very susceptible to spoilage due to oxidation and bacterial contamination. The combination of non-thermal processing interventions with nature-based alternatives is emerging as a useful tool for potential adoption for safe poultry meat products. Natural compounds are produced by living organisms that are extracted from nature and can be used as antioxidant, antimicrobial, and bioactive agents and are often employed for other existing purposes in food systems. Non-thermal technology interventions such as high-pressure processing, pulsed electric field, ultrasound, irradiation, and cold plasma technology are gaining increasing importance due to the advantages of retaining low temperatures, nutrition profiles, and short treatment times. The non-thermal unit process can act as an initial obstacle promoting the reduction of microflora, while natural compounds can provide an active obstacle either in addition to processing or during storage time to maintain quality and inhibit and control growth of residual contaminants. This review presents the application of natural compounds along with emerging non-thermal technologies to address risks in fresh poultry meat.

Non-thermal processing has an impact on the digestibility of the muscle proteins

Muscle proteins undergo several processes before being ready in a final consumable form. All these processes affect the digestibility of muscle proteins and subsequent release of amino acids and peptides during digestion in the human gut. The present review examines the effects of different processing techniques, such as curing, drying, ripening, comminution, aging, and marination on the digestibility of muscle proteins. The review also examines how the source of muscle proteins alters the gastrointestinal protein digestion. Processing techniques affect the structural and functional properties of muscle proteins and can affect their digestibility negatively or positively depending on the processing conditions. Some of these techniques, such as aging and mincing, can induce favorable changes in muscle proteins, such as partial unfolding or exposure of cleavage sites, and increase susceptibility to hydrolysis by digestive enzymes whereas others, such as drying and marination, can induce unfavorable changes, such as severe cross-linking, protein aggregation, oxidation induced changes or increased disulfide (S-S) bond content, thereby decreasing proteolysis. The underlying mechanisms have been discussed in detail and the conclusions drawn in the light of existing knowledge provide information with potential industrial importance.

Technologies for the Production of Meat Products with a Low Sodium Chloride Content and Improved Quality Characteristics-A Review

In recent years, consumer concerns regarding high levels of sodium chloride (NaCl) intake have increased, given the associated risk of cardiovascular disease. This has led food industries to consider lowering the use of sodium in food products. However, it is well known that the addition of NaCl to meat products enhances their quality, including water-holding capacity, emulsification capacity, juiciness, and texture. Thus, it is difficult to completely remove salt from meat products; however, it is possible to reduce the salt content using salt substitutes, flavor enhancers, textural enhancers, or other processing technologies. Several recent studies have also suggested that processing technologies, including hot-boning, high pressure, radiation, and pulsed electric fields, can be used to manufacture meat products with reduced salt content. In conclusion, as the complete removal of NaCl from food products is not possible, combined technologies can be used to reduce the NaCl content of meat products, and the appropriate technology should be chosen and studied according to its effects on the quality of the specific meat product.

Improvement of meat protein digestibility in infants and the elderly

Meat is a valuable protein source with a balanced composition of essential amino acids and various nutrients. This review aims to identify methods to improve digestion of meat proteins, as well as evaluate the digestive characteristics of infants and the elderly. Immature digestive conditions in infants, including a high gastric pH and low protease concentration, can hinder protein digestion, thus resulting in inhibited growth and development. Likewise, gastrointestinal (GI) tract aging and chronic health problems, including tooth loss and atrophic gastritis, can lead to reduction in protein digestion and absorption in the elderly compared with those in young adults. Moderate heating and several non-thermal technologies, such as aging, enzymatic hydrolysis, ultrasound, high-pressure processing, and pulsed electric field can alter protein structure and improve protein digestion in individuals with low digestive capacity.

Effects of Pulsed Electric Field Processing and Sous Vide Cooking on Muscle Structure and In Vitro Protein Digestibility of Beef Brisket

Pulsed electric fields (PEF) in conjunction with sous vide (SV) cooking has been explored for meat tenderisation. The aim of this experiment was to study the effect of PEF–SV treatment on the muscle structure and in vitro protein digestibility of beef brisket. Pulsed electric field treatment (specific energy of 99 ± 5 kJ/kg) was applied to bovine Deep and Superficial pectoral muscles in combination with sous vide (SV) cooking (60 °C for 24 h). A similar micro- and ultrastructure was detected between the control SV-cooked and PEF-treated SV-cooked pectoral muscles. The combined PEF–SV treatment increased the in vitro protein digestibility of the pectoral muscles by approximately 29%, in terms of ninhydrin-reactive free amino nitrogen released at the end of simulated digestion. An increment in proteolysis of the PEF-treated SV-cooked meat proteins (e.g., myosin heavy chains and C-protein) during simulated digestion was also observed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. More damaged muscle micro- and ultrastructure was detected in PEF-treated SV-cooked muscles at the end of in vitro digestion, showing its enhanced digestive proteolysis compared to the control cooked meat.