Meat Irradiation: A Comprehensive Review of Its Impact on Food Quality and Safety

Effect of electron beam irradiation on the quality of chicken during post-mortem ageing

The effects of electron beam irradiation (0, 4, and 8 kGy) on the quality of fresh chicken breast muscle during post-mortem ageing (0, 1, 3, and 5 days) were evaluated. The results suggested that the pH value and water-holding capacity of the chicken breast muscle were reduced, and the water was migrated. The color of the chicken breast muscle improved after irradiation, with decreased in L* and b* values and increased in a* values and oxymyoglobin content. Furthermore, irradiation significantly lowered shear force, raised the myofibrillar fragmentation index (MFI), and enhanced chicken breast tenderness. RT-qPCR and western blotting analyses showed that electron beam irradiation influenced the tenderness of chicken breast muscle by regulating apoptosis through mitochondrial, death receptor, and ERS pathways during post-mortem ageing. In conclusion, these results suggested that electron beam irradiation improved tenderness through apoptosis and changed chicken breast quality (such as color, pH, and moisture).

Isolation and characterization of virulent bacteriophages and controlling Salmonella Enteritidis biofilms on chicken meat

Salmonella is a prominent zoonotic pathogen that continues to represent a large threat to food safety and public health worldwide. Concurrently, the inappropriate use of antibiotics has led to the development of antibiotic-resistant strains of Salmonella, highlighting the urgent need for new approaches to manage these bacteria. In this context, virulent bacteriophages are increasingly recognized as a potential and effective biological control method against Salmonella. This study identifies two newly isolated virulent Salmonella phages, phage vB_SalD_ABTNLS3 (S3 for short) and phage 2-3 (2-3 for short). Both phages exhibited effectiveness in preventing biofilm formation and reducing biofilm. S3 and 2-3 could maximize the inhibition of more than 70% and 91% of biofilm formation after 48 h of treatment, and maximize the removal of more than 59% and 96% of mature biofilm after 3 h and 5 h, respectively. Based on these, our study assessed the efficacy of 2-3 in controlling Salmonella enterica serotype Enteritidis (SE) on raw chicken meat at 4°C with varying MOIs, including 1, 100, and 10,000. The maximum reduction observed in SE on chicken meat was 1.15 log10 CFU/mL following a 12-h treatment with the 2-3, a significant decrease of more than 92% compared to the initial levels present in the experiment (MOI = 10,000). In conclusion, our phages performed well in controlling biofilm and disinfecting refrigerated food at 4°C, suggesting their potential as biological agents to reduce Salmonella contamination in the food industry.

Modeling the growth and volatile metabolite production of spoilage-causing Brochothrix thermosphacta on solid meat substrates under modified atmospheres

Spoilage microorganisms including Brochothrix thermosphacta are associated with various volatile organic compounds (VOCs) and off-odors in meat. Modified atmosphere packaging (MAP) limits microbial growth and affects metabolic activities. However, the exact impact of gas compositions on B. thermosphacta still remains unclear, especially regarding the direct relationship between its growth and VOC accumulation. This study thus aimed to investigate and model these behaviors by growing B. thermosphacta on solid pork simulation media under different packaging atmospheres. Five O2/CO2/N2 ratios (v/v%: air, 0/0/100, 60/40/0, 5/40/55, 0/40/60) were examined to study the synergy of MAP gases on the aerobic/anaerobic metabolism of B. thermosphacta. The quantities of VOCs (ppbv) were fitted against respective bacterial numbers (log CFU/g) of different individual samples assessed at regular storage intervals. Results suggest that VOCs including acetoin, ethanol, benzaldehyde, and 3-methyl-1-butanol are the major metabolites of B. thermosphacta. Under air, the observable increase of multiple VOCs started at 5.9-6.6 log CFU/g and was closely correlated with microbial growth. In contrast, 100 % N2 caused low acetoin levels and high ethanol emission because of shifting to an anaerobic metabolism. Under high-CO2 atmospheres, concentrations of most VOCs were reduced, likely linked to limited microbial counts. Through this study, predictive modeling offers novel insights into the impact of the atmosphere on bacterial growth and VOC production. This helps to fully understand microbial spoilage and contributes to the development of suitable meat storage strategies.

Gamma rays irradiated polysaccharides: A review of the structure, physicochemical properties, biological activities alteration, and future food applications

Recently, there has been a growing interest in using radiation to change various properties of polysaccharides. This review gives a more detailed examination of the effects of gamma radiation on polysaccharides and its association with their techno-functional and biological properties following irradiation. Gamma irradiation is a potent tool for modifying the structure and properties of polysaccharides, enhancing their functionality in food applications. This review explores the effects of gamma irradiation on polysaccharides, focusing on changes in their molecular structure, physicochemical properties, and biological activities. Gamma irradiation induces chain scission and cross-linking in polysaccharides, leading to alterations in molecular weight, solubility, and viscosity. These structural modifications often enhance antioxidants, antimicrobial, and anti-inflammatory activities, expanding their potential use in food products. Gamma-irradiated polysaccharides exhibit improved gelation, emulsification, and film-forming abilities, making them suitable for various food applications such as thickeners, stabilizers, and edible coatings. The review also discusses the safety and regulatory aspects of using gamma-irradiated polysaccharides in food products. Future research directions are proposed to optimize irradiation conditions and further explore the multifunctional benefits of these modified polysaccharides, ultimately contributing to the development of innovative, functional food products.

Characterization of prepared soft-shelled turtle dishes of different pretreatment combined with irradiation based on flavor profiles using E-nose, E-tongue and HS-SPME-GC-MS

The effects of different pretreatment combined with irradiation on the flavor profiles of prepared soft-shelled turtle dishes were explored by using electronic nose, electronic tongue and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that electronic nose analysis indicated distinct odor profiles before and after irradiation, with PCA effectively differentiating them. The low-temperature pretreatment group had the smallest difference from the control (CK). After 180 days of storage, odor profiles of all samples converged, with low-temperature, 0.1 % rosemary, and 0.1 % TBHQ groups showing minimal differences from CK. Electronic tongue profiles showed no significant differences among treatments, with PCA unable to effectively distinguish most groups, except for the 0.1 % rosemary and 0.1 % sesamol groups. The results of HS-SPME-GC-MS analysis showed that the volatile compounds of the samples of each treatment were significantly different. The 6 kGy (kilogray) irradiation group, the low temperature pretreatment and the control group (CK) clustered into one category. After 180 d of storage at room temperature, only the low temperature pretreatment group and the control group (CK) were clustered into one category. The results of relative odor activity value (ROAV) showed that the key flavor compounds of prepared soft-shelled turtle dishes were heptanal, octanal, (E)-2-octenal, nonanal, (E,E)-2,4-nonadienal, decanal, (E)-2-decenal, (E,E)-2,4-decadienal, 2-undecanal, 1-octen-3-ol, and 2-pentylfuran. Aldehydes contents in the samples increased after irradiation, which was the main components leading to the off-odor of prepared soft-shelled turtle dishes after irradiation, and the key flavor compounds of the samples decreased after 180 d of storage at room temperature. In conclusion, low temperature or pretreatment of three antioxidants could maintain the flavor of prepared soft-shelled turtle dishes after irradiation, and low temperature had the best effect. This study could provide theoretical reference for the application of irradiation technology in the sterilization and preservation processing of prepared soft-shelled turtle dishes and its flavor control.

Contributing factors to the migration of antimicrobials in active packaging films

Antimicrobial active packaging plays a key role in food quality and safety. The addition of antimicrobial agents in packaging production aims to release these agents from film to food, thereby preventing, reducing, or eliminating the contamination caused by pathogens or food spoilage microorganisms. This review provides an overview of the antimicrobial active packaging and gives an insight of the antimicrobials that have been used to manufacture antimicrobial active films. Additionally, it discusses the findings of studies that have developed active films, identifying the related factors with the release of antimicrobials from film to packaged food, as well as their possible mechanisms of release. Four interrelated factors that affect the release of antimicrobial agents have been identified. The first one addresses the film properties, the second one corresponds to food characteristics, the third one environmental condition, and the last one the attributes of the antimicrobial agent itself. There have been reported two mechanisms for explaining the antimicrobial release. The first mechanism addresses the water as the main regulator, and the second implies a natural diffusion of antimicrobials. The identification of related factors with the release can contribute to optimizing new methods in the design of antimicrobial active packaging.

Protein oxidation: The effect of different preservation methods or phenolic additives during chilled and frozen storage of meat/meat products

Lipid and protein oxidation have significant effects on the shelf-life and nutritional value of meat and meat products. While lipid oxidation has been extensively studied, it has been recognized that proteins are also susceptible to oxidation. However, the precise mechanisms of oxygen-induced amino acid and protein modifications in the food matrix remain unclear. This review comprehensively explores the impact of various preservation techniques, including high hydrostatic pressure (HHP), irradiation (IR), and modified atmosphere packaging (MAP), on protein oxidation during chilled or frozen storage of meat products. While these techniques have shown promising results in extending shelf-life, their effects on protein oxidation are dose-dependent and must be carefully controlled to maintain product quality. Preservation techniques involving the use of phenolic additives have demonstrated synergistic effects in mitigating protein oxidation during storage. Notably, natural phenolic additives have shown comparable efficacy compared to artificial antioxidants. Additionally, incorporating phenolic additives into bio-edible films has shown promise in combating protein oxidation.

How lipids, as important endogenous nutrient components, affect the quality of aquatic products: An overview of lipid peroxidation and the interaction with proteins

As the global population continues to grow and the pressure on livestock and poultry supply increases, the oceans have become an increasingly important source of quality food for future generations. However, nutrient-rich aquatic product is susceptible to lipid oxidation during storage and transport, reducing its nutritional value and increasing safety risks. Therefore, identifying the specific effects of lipid oxidation on aquatic products has become particularly critical. At the same time, some lipid oxidation products have been found to interact with aquatic product proteins in various ways, posing a safety risk. This paper provides an in-depth exploration of the pathways, specific effects, and hazards of lipid oxidation in aquatic products, with a particular focus on the interaction of lipid oxidation products with proteins. Additionally, it discusses the impact of non-thermal treatment techniques on lipids in aquatic products and examines the application of natural antioxidants in aquatic products. Future research endeavors should delve into the interactions between lipids and proteins in these products and their specific effects to mitigate the impact of non-thermal treatment techniques on lipids, thereby enhancing the safety of aquatic products and ensuring food safety for future generations.

How Argentinian Consumers Perceive the Safety of Irradiated Foods

Food irradiation is a process used for various purposes, the main function of which is food safety. Although food irradiation has been used to ensure food safety, most consumers are unaware of the basic concepts of irradiation, misinterpreting information and showing a negative perception towards food treated with ionizing radiation. This research aimed to develop the cross-cultural adaptation and validation of the Awareness Scale on Consumption of Irradiated Foods (ASCIF) for the Argentine population and culture. The scale included 31 items covering 4 factors: safety of irradiated foods (S), concepts (C), labeling (L), and awareness (A), which were able to assess the Argentine population's knowledge of irradiated foods. The total number of respondents was 500 and the data were collected by means of an electronic survey. Statistical tests were carried out which met the validity assumptions and confirmed the validity and consistency of the psychometric scale by means of confirmatory factor analysis (CFA), Cronbach's alpha coefficient, and exploratory structural equation modelling (ESEM). Analysis of the results showed that the majority of consumers are unaware of the benefits of irradiated foods. It was found that the scale met the criteria for evidence of validity and consistency, proving to be an efficient tool for assessing potential challenges and opportunities in the Argentinian market for irradiated foods. The process was approved by the Research Ethics Committees of Brazil and Argentina and followed the adaptation methodologies of the International Test Commission (ITC) with processes of translations and retranslations and application of the scale in Argentina.

Optimization Function for Determining Optimal Dose Range for Beef and Seed Potato Irradiation

The objective of this study is to develop a universally applicable approach for establishing the optimal dose range for the irradiation of plant and animal products. The approach involves the use of the optimization function for establishing the optimal irradiation dose range for each category of plant and animal product to maximize the suppression of targeted pathogens while preserving the surrounding molecules and biological structures. The proposed function implies that pathogens found in the product can be efficiently suppressed provided that irradiation is performed with the following criteria in mind: a high irradiation dose uniformity, a high probability of irradiation hitting pathogens and controlled heterogeneity of radiobiological sensitivity of pathogens. This study compares the optimal dose ranges for animal and plant products using beef tenderloin and seed potato tubers as examples. In a series of experiments, our team traced the dose dependencies of myoglobin oxidation in beef and the amount of potential damage to albumin's native structure. The behavior patterns of myoglobin derivatives and the amount of potential damage to albumin found in this study determined the optimal dose range, which appeared to be wider for beef irradiation compared to that for seed potato tubers, as they do not require uniform irradiation of the entire volume since targeted phytopathogens are predominantly found within the surface layers of the tubers. The use of proprietary methods involving spectrophotometry and high-performance liquid chromatography-mass spectrometry provides a novel perspective on the quantitative assessment of the myoglobin oxidation level and the potential damage to albumin's native structure.

Exploring the Nexus of Feeding and Processing: Implications for Meat Quality and Sensory Perception

The intrinsic quality of meat is directly related to muscle and fat tissues. Factors such as the rate and extent of anaerobic glycolysis affect muscle pH, influencing the meat's color, water holding, and texture. Postmortem anomalies can result in deviations from this intrinsic quality. The animals' diet plays a crucial role in meat quality. Specific nutrients, such as proteins, vitamins, and minerals, affect meat's texture, flavor, and juiciness. Feeds rich in omega-3 fatty acids can improve the sensorial quality of meat. Meat processing and methods such as aging, marinating, and cooking affect the texture, flavor, and juiciness, which can be evaluated by specific equipment or trained or untrained consumers. This comprehensive review investigates the relationship between animal feeding practices and meat processing techniques and their combined impact on meat quality and sensory perception. By synthesizing recent research, we explore how various feeding protocols (including diet composition and feed additives) and processing methods shape meat products' nutritional value, texture, flavor profile, and overall consumer appeal. Understanding this nexus is crucial for optimizing meat quality while ensuring sustainability and safety in the food supply chain.

Electromagnetic wave-based technology for ready-to-eat foods preservation: a review of applications, challenges and prospects

In recent years, the ready-to-eat foods market has grown significantly due to its high nutritional value and convenience. However, these foods are also at risk of microbial contamination, which poses food safety hazards. Additionally, traditional high-temperature sterilization methods can cause food safety and nutritional health problems such as protein denaturation and lipid oxidation. Therefore, exploring and developing effective sterilization technologies is imperative to ensure food safety and nutritional properties, and protect consumers from potential foodborne diseases. This paper focuses on electromagnetic wave-based pasteurization technologies, including thermal processing technologies such as microwave, radio frequency, and infrared, as well as non-thermal processing technologies like ultraviolet, irradiation, pulsed light, and photodynamic inactivation. Furthermore, it also reviews the antibacterial mechanisms, advantages, disadvantages, and recent applications of these technologies in ready-to-eat foods, and summarizes their limitations and prospects. By comparing the limitations of traditional high-temperature sterilization methods, this paper highlights the significant advantages of these pasteurization techniques in effectively inhibiting microbial growth, slowing lipid oxidation, and preserving food nutrition and flavor. This review may contribute to the industrial application and process optimization of these pasteurization technologies, providing an optimal choice for preserving various types of ready-to-eat foods.

Modified Chitosan-Based Coating/Packaging Composites with Enhanced Antibacterial, Antioxidant, and UV-Resistant Properties for Fresh Food Preservation

Chitosan-based biomass packaging materials are a promising material for food preservation, but their limited solubility, antioxidant capacity, UV resistance, and mechanical properties severely restrict their application. In this study, we developed a novel chitosan-based coating/packaging composite (QCTO) using quaternary ammonium salt and tannic acid (TA)-modified chitosan (QCS-TA) and oxidized chitosan (OCS). The introduction of quaternary ammonium salt and TA effectively improves the water solubility and antibacterial, antioxidant, and UV-resistant properties of chitosan. The Schiff-base bond formed between OCS and QCS-TA, along with the TA-mediated multiple interactions, conferred the prepared composite film with good mechanical properties (69.9 MPa tensile strength) and gas barrier performance to water (14.3 g·h-1·m-2) and oxygen (3.5 g·mm·m-2·h-1). Meanwhile, the prepared QCTO composites demonstrate excellent biocompatibility and safety and are applied as coatings for strawberries and bananas as well as packaging films for mushrooms. These preservation experiments demonstrated that the prepared composites are able to effectively reduce weight loss, prevent microbial growth, maintain color, and significantly prolong the shelf life of fresh products (bananas, strawberries, and mushrooms extended shelf life by 6, 5, and 6 days, respectively). Therefore, the developed QCTO coating/packaging film shows great potential for applications in the field of food preservation and packaging.

Characterization of two virulent Salmonella phages and transient application in egg, meat and lettuce safety

Salmonella, a prominent foodborne pathogen, has posed enduring challenges to the advancement of food safety and global public health. The escalating concern over antibiotic misuse, resulting in the excessive presence of drug residues in animal-derived food products, necessitates urgent exploration of alternative strategies for Salmonella control. Bacteriophages emerge as promising green biocontrol agents against pathogenic bacteria. This study delineates the identification of two novel virulent Salmonella phages, namely phage vB_SalS_ABTNLsp11241 (referred to as sp11241) and phage 8-19 (referred to as 8-19). Both phages exhibited efficient infectivity against Salmonella enterica serotype Enteritidis (SE). Furthermore, this study evaluated the effectiveness of two phages to control SE in three different foods (whole chicken eggs, raw chicken meat, and lettuce) at different MOIs (1, 100, and 10000) at 4°C. It's worth noting that sp11241 and 8-19 achieved complete elimination of SE on eggs after 3 h and 6 h at MOI = 100, and after 2 h and 5 h at MOI = 10000, respectively. After 12 h of treatment with sp11241, a maximum reduction of 3.17 log10 CFU/mL in SE was achieved on raw chicken meat, and a maximum reduction of 3.00 log10 CFU/mL was achieved on lettuce. Phage 8-19 has the same effect on lettuce as sp11241, but is slightly less effective than sp11241 on chicken meat (a maximum 2.69 log10 CFU/mL reduction). In conclusion, sp11241 and 8-19 exhibit considerable potential for controlling Salmonella contamination in food at a low temperature and represent viable candidates as green antibacterial agents for food applications.

Research on Food Preservation Based on Antibacterial Technology: Progress and Future Prospects

The nutrients present in food are not only prone to a series of physicochemical reactions but also provide conditions for the growth and reproduction of foodborne microorganisms. In recent years, many innovative methods from different fields have been introduced into food preservation, which extends the shelf life while maximizing the preservation of the original ingredients and properties of food. In this field, there is a lack of a systematic summary of new technologies emerging. In view of this, we overview the innovative methods applied to the field of food preservation in recent 3 years, focusing on a variety of technological approaches such as antimicrobial photodynamic therapy based on nanotechnology, electromagnetic radiation sterilization based on radiation technology, and antimicrobial peptides based on biomolecules. We also discuss the preservation mechanism and the application of the different methods to specific categories of products. We evaluated their advantages and limitations in the food industry, describing their development prospects. In addition, as microorganisms are the main causes of food spoilage, our review also has reference significance for clinical antibacterial treatment.

Recent advances in spoilage mechanisms and preservation technologies in beef quality: A review

Beef is a popular meat product that can spoil and lose quality during postharvest handling and storage. This review examines different preservation methods for beef, from conventional techniques like low-temperature preservation, irradiation, vacuum packing, and chemical preservatives, to novel approaches like bacteriocin, essential oil, and non-thermal technologies. It also discusses how these methods work and affect beef quality. The review shows that beef spoilage is mainly due to enzymatic and microbial activities that impact beef freshness, texture, and quality. Although traditional preservation methods can extend beef shelf life, they have some drawbacks and limitations. Therefore, innovative preservation methods have been created and tested to improve beef quality and safety. These methods have promising results and potential applications in the beef industry. However, more research is needed to overcome the challenges and barriers for their commercialization. This review gives a comprehensive and critical overview of the current and emerging preservation methods for beef and their implications for the beef supply chain.

Balancing Freshness and Sustainability: Charting a Course for Meat Industry Innovation and Consumer Acceptance

The agribusiness sector is constantly seeking solutions to enhance food security, sustainability, and resilience. Recent estimates indicate that one-third of the total food production remains unused due to waste or limited shelf life, resulting in negative environmental and ethical consequences. Consequently, exploring technological solutions to extend the shelf life of food products could be a crucial option to address this issue. However, the success of these technological solutions is closely linked to the perception of the end-consumers, particularly in the short term. Based on these considerations, this paper presents a systematic literature review of the main technological innovations in the fresh meat industry and of consumers' perceptions of such innovations. Regarding innovative technologies, this review focused on active and smart packaging. Amidst various technological innovations, including the utilization of fundamental matrices and natural additives, a noticeable gap exists in consumer perception studies. This study represents the first comprehensive compilation of research on consumers' perceptions and acceptance of innovations designed to extend the shelf life of fresh meat. Moreover, it sheds light on the existing barriers that hinder the complete embrace of these innovations.

Volatile Compound Markers in Beef Irradiated with Accelerated Electrons

This study focuses on the behavior of volatile organic compounds in beef after irradiation with 1 MeV accelerated electrons with doses ranging from 0.25 kGy to 5 kGy to find reliable dose-dependent markers that could be used for establishing an effective dose range for beef irradiation. GC/MS analysis revealed that immediately after irradiation, the chemical yield and accumulation rate of lipid oxidation-derived aldehydes was higher than that of protein oxidation-derived aldehydes. The nonlinear dose-dependent relationship of the concentration of volatile organic compounds was explained using a mathematical model based on the simultaneous occurrence of two competing processes: decomposition of volatile compounds due to direct and indirect action of accelerated electrons, and accumulation of volatile compounds due to decomposition of other compounds and biomacromolecules. A four-day monitoring of the beef samples stored at 4 °C showed that lipid oxidation-derived aldehydes, protein oxidation-derived aldehydes and alkanes as well as alcohol ethanol as an indicator of bacterial activity were dose-dependent markers of biochemical processes occurring in the irradiated beef samples during storage: oxidative processes during direct and indirect action of irradiation, oxidation due to the action of reactive oxygen species, which are always present in the product during storage, and microbial-enzymatic processes. According to the mathematical model of the change in the concentrations of lipid oxidation-derived aldehydes over time in the beef samples irradiated with different doses, it was found that doses ranging from 0.25 kGy to 1 kGy proved to be most effective for beef irradiation with accelerated electrons, since this dose range decreases the bacterial content without considerable irreversible changes in chemical composition of chilled beef during storage.

The multi-scale structure changes of γ-ray irradiated potato starch to mitigate pasting/digestion properties

The comprehensive understanding of multi-scale structure of starch and how the structure regulates the pasting/digestion properties remain unclear. This work investigated the effects of γ-ray irradiation with different doses on multi-scale structure and pasting/digestion properties of potato starch. Results indicated that γ-ray at lower doses (<20 kGy) had little effect on micromorphology of starch, increased mainly the amylose content and the thickness of amorphous region while decreased crystallinity, double helix content and lamellar ordering. With the increase of dose, the internal structure of large granules was destroyed, resulting in the depolymerization of starch to form more short-chains and to reduce molecular weight. Meanwhile, amylose content decreased due to the depolymerization of amylose. The enhanced double helix content, crystallinity, lamellar ordering and structural compactness manifested the formation of the thicker and denser starch structure. These structure changes resulted in the decreased viscosity, the increased stability and anti- digestibility of paste.

Headspace Solid-Phase Microextraction/Gas Chromatography-Mass Spectrometry and Chemometric Approach for the Study of Volatile Profile in X-ray Irradiated Surface-Ripened Cheeses

X-ray irradiation is an emerging non-thermal technology that is used as a preservation and sanitization technique to inactivate pathogens and spoilage organisms, increasing the shelf life of products. In this work, two different types of surface-ripened cheeses, Brie and Camembert, produced with cow milk, were treated with X-rays at three dose levels, 2.0, 4.0 and 6.0 kGy, to evaluate the irradiation effects on the volatile profile using a volatolomic approach. The headspace solid-phase microextraction (HS-SPME) technique combined with gas chromatography-mass spectrometry (GC-MS) was used to extract and analyze the volatile fraction from these dairy matrices. The HS-SPME method was optimized by a central composite design in combination with a desirability optimization methodology. The Carboxen/PDMS fiber, 50 °C for extraction temperature and 60 min for time extraction were found to be the best parameter settings and were applied for this investigation. The obtained fingerprints demonstrated that the irradiation-induced changes are dose dependent. The X-ray irradiation produced many new volatiles not found in the non-irradiated samples, but it also varied the amount of some volatiles already present in the control. Specifically, aldehydes and hydrocarbons increased with the irradiation dose, whereas alcohols, carboxylic acids, esters, methyl esters, ketones, lactones and sulfur-containing compounds showed a non-linear dependence on the dose levels; indeed, they increased up to 4.0 kGy, and then decreased slightly at 6.0 kGy. This trend, more evident in the Camembert profile, is probably due to the fact that these compounds are involved in different oxidation mechanisms of lipids and proteins, which were induced by the radiation treatment. In these oxidative chemical changes, the production and degradation processes of the volatiles are competitive, but at higher doses, the decomposition reactions exceed those of formation. A principal component analysis and partial least square discriminant analysis were used to discriminate between the treated and untreated samples. Moreover, this study allowed for the identification of potential markers of X-ray treatment for the two cheeses, confirming this approach as a useful tool for the control of irradiated surface-ripened cheeses.

Quality of pork after electron-beam irradiation: A meta-analysis study

Background and Aim

Irradiation has become a preferred method for pork preservation in recent years. Electron-beam irradiation is notably recognized for its feasibility and safety among various irradiation methods. This meta-analysis study aims to elucidate the impact of electron-beam irradiation on oxidation parameters, color, sensory attributes, and microbiological conditions in pork.

Materials and Methods

A total of 79 data from 22 articles were aggregated into an extensive database. The irradiation dose ranged from 0 to 20 kGy in this current meta-analysis. The observed parameters encompassed oxidation, color, sensory attributes, and microbiological conditions. A mixed-model approach was used to perform the meta-data analysis, in which irradiation dose was treated as fixed effects and distinct studies (articles) as random effects.

Results

Electron-beam irradiation resulted in an increase in thiobarbituric acid-reactive substances levels and peroxide-oxygen value of pork (p < 0.01). Conversely, total volatile-base-nitrogen values (p < 0.05) were observed. Following irradiation, the pH value, lightness (L*), redness (a*), and yellowness (b*) remained unaffected. Pork color tended to decrease after irradiation treatment (p = 0.095 and p = 0.079, respectively) at 7 and 14 days of storage. The irradiation process resulted in an increase in the values of texture and juiciness parameters (p < 0.05). However, electron-beam irradiation resulted in decreased overall acceptability (p = 0.089). In terms of microbiological status, electron-beam irradiation led to a reduction in the populations of Salmonella (p < 0.01), Escherichia coli (p < 0.01), Listeria monocytogenes (p < 0.05), and coliforms (p < 0.05) at 7 and 14 days of storage.

Conclusion

Electron-beam irradiation enhances lipid peroxidation in porcine meat. The color of the meat remained unchanged after treatment. However, with regard to sensory properties, electron-beam irradiation showed a tendency to decreased overall acceptability. Most microbiological parameters decreased following electron-beam irradiation.

ATR-FTIR spectroscopy combined with chemometrics to assess the spectral markers of irradiated baijius and their potential application in irradiation dose control

Although some methods have been proposed for the identification of irradiated baijius, they are often costly, time-consuming, and destructive. It is also unclear what instrumentation can be used to fully characterize the quality changes in irradiated baijius. To address this issue, this study pioneers the use of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy in combination with chemometrics to open up new avenues for characterizing irradiated baijius and their quality control. Principal component analysis, five spectral pre-processing methods (Savitzky-Golay smoothing (S-G), second-order derivative (SD), multiple scattering correction (MSC), S-G + SD and S-G + MSC), five wavelength selection methods (random forest variable importance (RFVI), two-dimensional correlation spectroscopy (2D-COS), variable importance in projection (VIP), ReliefF, and Venn), and three classification models (partial least squares-discriminant analysis (PLS-DA), random forest (RF), and grasshopper optimization algorithm-based support vector machine (GOA-SVM)) were integrated into the analytical framework of ATR-FTIR spectroscopy, aiming to accurately identify baijiu samples according to different irradiation doses and to search for irradiation-induced spectral difference characteristics (spectral markers). The results showed that SD was the best spectral pre-processing method, and RF models constructed using the 20 most competitive and discriminative spectral markers (selected by Venn) could achieve accurate identification of baijiu samples based on irradiation dose (0, 4, 6, and 8 kGy). After Pearson correlation analysis, the five significantly (P＜0.05) changed spectral markers (1596, 2025, 2309, 2329, and 2380 cm-1) were attributed to changes in the content of total acids, alcohols, and aromatic compounds. These findings demonstrate for the first time the potential of ATR-FTIR spectroscopy as a fast, low-cost, and non-destructive tool for the characterization and identification of irradiated baijiu samples. This approach may also offer a promising solution for labeling management of irradiated foods, vintage identification of baijius, and brand protection.

Effects of Gamma-Ray Irradiation of Bacteria Colonies in Animal Feeds and on Growth and Gut Health of Weaning Piglets

Animal feeds contain a substantial number and diversity of microorganisms, and some of them have pathogenic potential. The objectives of this study were to investigate the effects of different doses of gamma (γ)-ray irradiation on the bacteria count in different types of feed and then to test the effect of γ-ray-irradiation-treated fishmeal on the gut health and growth performance of weaning piglets. In trial 1, three fishmeal samples, two feather meal samples, three meat meal samples, three soybean meal samples, and three vitamin complexes were treated with γ-ray irradiation doses of 0, 3, 6, or 9 kGy. The 6 and 9 kGy doses eliminated most of the bacteria in the feed but also resulted in a loss of vitamin C and B1. In trial 2, 96 weaning piglets were fed one of the following three diets with eight replicates (pens) per group over a 14-day period: (1) the control diet-the basal diet supplemented with 6% fishmeal with a low bacteria count (40 CFU/g) and no E. coli; (2) the fishmeal-contaminated diet (FM-contaminated) diet-the basal diet supplemented with 6% fishmeal with a high bacteria count (91,500 CFU/g) and E. coli contamination; and (3) the irradiated fishmeal (irradiated FM) diet-the basal diet supplemented with γ-ray-irradiation-treated E. coli-contaminated fishmeal. The piglets that received the FM-contaminated diet had significantly lower average daily gain and a greater diarrhea index compared to those fed the control diet, whereas γ-ray irradiation treatment abrogated the negative effect of the E. coli-contaminated fishmeal. Collectively, γ-ray irradiation at a dose of 6-9 kGy was sufficient to eliminate the microorganisms in the feed, thereby benefitting the growth performance and gut health of the weaning piglets.

Hemoglobin Derivatives in Beef Irradiated with Accelerated Electrons

The efficiency of food irradiation depends on the accuracy of the irradiation dose range that is sufficient for inhibiting microbiological growth without causing an irreversible change to the physical and chemical properties of foods. This study suggests that the concentration of hemoglobin derivatives can be used as a criterion for establishing the limit for chilled beef irradiation at which irradiation-induced oxidation becomes irreversible. The express spectrophotometry method for estimating the hemoglobin derivative concentration shows a nonlinear increase in methemoglobin concentration from 15% to 50% in beef irradiated by accelerated electrons with the doses ranging from 250 Gy to 10,000 Gy. The monitoring of the hemoglobin derivative concentration for three days after irradiation shows nonmonotonous dependencies of methemoglobin concentration in beef in the storage time since the oxidation of hemoglobin occur as a result of irradiation and biochemical processes in beef during storage. The proposed method based on the quantitative analysis of the hemoglobin derivative concentration can be used to estimate the oxidation level for irradiation of foods containing red blood cells. The study proposes a model that describes the change in hemoglobin derivative concentration in beef after irradiation considering that oxidation of hemoglobin can be triggered by the direct ionization caused by accelerated electrons, biochemical processes as a result of bacterial activity, and reactive oxygen species appearing during irradiation and storage. This research throws light on the mechanisms behind food irradiation during storage that should be taken into account for selecting the optimal parameters of irradiation.

The Application of Ultraviolet Treatment to Prolong the Shelf Life of Chilled Beef

This study simulated the storage conditions of chilled beef at retail or at home, and the sterilization and preservation effects of short-time ultraviolet irradiation were studied. The conditions of different irradiation distances (6 cm, 9 cm, and 12 cm) and irradiation times (6 s, 10 s, and 14 s) of ultraviolet (UV) sterilization in chilled beef were optimized, so as to maximally reduce the initial bacterial count, but not affect the quality of the chilled beef. Then, the preservation effect on the chilled beef after the optimized UV sterilization treatment during 0 ± 0.2 °C storage was investigated. The results showed that UV irradiation with parameters of 6 cm and 14 s formed the optimal UV sterilization conditions for the chilled beef, maximally reducing the number of microorganisms by 0.8 log CFU/g without affecting lipid oxidation or color change. The 6 cm and 14 s UV sterilization treatment of the chilled beef was able to reduce the initial microbial count, control the bacterial growth, and delay the increase in the TVB-N values during storage. Compared with the control group, the total bacterial count decreased by 0.56-1.51 log CFU/g and the TVB-N value decreased by 0.20-5.02 mg N/100 g in the UV-treated group. It was found that the TBARS value of the UV treatment group increased during late storage; on days 9-15 of storage, the TBARS values of the treatment group were 0.063-0.12 mg MDA/kg higher than those of the control group. However, UV treatment had no adverse impact on the pH, color, or sensory quality of chilled beef. These results prove that UV treatment can effectively reduce the microbial count on the surface of beef and improve its microbial safety, thus maintaining the quality of beef and prolonging its shelf life. This study could provide a theoretical basis for the preservation technology of chilled beef in small-space storage equipment.