Recent development in the application of alternative sterilization technologies to prepared dishes: A review

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.

Molecular and microstructural changes of chicken breasts in preheating-freezing-reheating process: The role of ice crystal formation and growth

The molecular and microstructural evolution of meat during preheating-freezing-reheating process remained unclear, limiting the quality improvement of prepared dishes. This study revealed this evolution of chicken breasts by comparing three groups with various preheating states to fully preheated (control) and fresh samples. By ice crystal characterization, fresh samples typically form small, evenly distributed intracellular ice crystals, whereas preheating promoted the formation of irregular extracellular crystals. All samples exhibited larger ice crystals after recrystallization. Results showed that ice crystal formation primarily induced protein unfolding and aggregation, while recrystallization predominantly drove lipid oxidation and microstructural damage. Control samples displayed extreme aggregation and microstructural damage, with significantly higher turbidity and hydrophobic interaction values (p < 0.05), leading to texture deterioration. On the other hand, moderate preheating samples (CV2 [where CV is cooked value], preheated to core temperature reached 68.05°C) resulted in lower protein aggregation and water loss, with lower values in turbidity, intrinsic fluorescence intensity, covalent bonds content, and area of T2i relaxation peaks, enhancing texture quality. Scanning electron microscopy images indicated that intracellular ice crystals in fresh samples primarily caused cellular structure damage, and extracellular ice crystals in control and CV2 samples contributed to the disruption and curling of connective tissue. Overall, preheating impacted the final qualities by affecting ice crystal properties, resulting in a better maintained molecular structure and microstructure of CV2 samples compared to the control samples. PRACTICAL APPLICATION: This study revealed the molecular and microstructural change of chicken breasts during preheating-freezing-reheating process, recommending an easy way to improve prepared meat qualities: reducing the preheating state to an appropriate level rather than fully preheated. Besides, the different ice crystal properties in chicken breasts with different preheating states offered a theoretical foundation for frozen control strategy of prepared meat. These results provide critical insights into the quality control and industrial upgrade of prepared dishes.

Non-thermal plasma decontamination of microbes: a state of the art

Microbial decontamination is a critical concern in various sectors, from healthcare to food processing. Traditional decontamination methods, while effective to a degree, present limitations in terms of environmental impact, efficiency, and potential harm to the target material. This review investigates the emerging realm of non-thermal plasma (NTP) as a promising alternative for microbial decontamination, emphasizing its mechanisms, reactor designs and applications. The mechanism decomposed into physical, chemical and biological effects of plasma, are elaborated upon to provide a foundational understanding of the intrinsic principles of plasma decontamination. Except for the generation type of NTP, reactors and other parameters by which NTP achieves microbial decontamination, emphasizing the design considerations and parameters that influence its efficacy. Moreover, the latest applications of NTP in decontaminating air, water, and surfaces, supported by the latest research findings in each domain are explored. Additionally, the perspectives on the future research tendencies of NTP decontamination and disinfection are highlighted with potential avenues for exploration and innovation. Through this comprehensive review, the aim is to underscore the potential of NTP, particularly DBD plasma, as a versatile, efficient, and environmentally friendly method for microbial decontamination.

Antimicrobial activity of octyl gallate nanoemulsion combined with photodynamic technology and its effect on food preservation

Photodynamic inactivation, as a safe and effective antimicrobial technology that does not damage the organoleptic properties of the food itself, decreases the use of preservatives and is gradually gaining attention in the food industry. This study selected octyl gallate (OG) as an antimicrobial photosensitizer with eucalyptus oil as the oil phase and prepared it as an octyl gallate nanoemulsion (OG-NE) to ensure the delivery of the photosensitizer. Escherichia coli and Staphylococcus aureus inactivation with the OG-NE combined with photodynamic technology, as well as the effect on the quality of food products, was investigated. The results showed the successful preparation and homogeneous distribution of the OG-NE with an encapsulation rate of 85.18 %. The OG-NE's ability to produce single oxygen (1O2) was significantly higher, as shown by 1O2 production. The OG-NE combined photodynamic technique confirmed the effectiveness of microbial removal, demonstrating a significant increase in reactive oxygen species (ROS) and the permeability of the cell membrane. The effect of the OG-NE combined photodynamic technology on perch (microbiology, pH, whiteness, water holding capacity, TVB-N and TBA) and litchi (weight loss, titratable acid and sugar content) preservation was assessed. Food preservation experiments revealed that the OG-NE combined photodynamic technology exhibited a positive effect on food quality. The results indicated that the combination of the OG-NE and photodynamic technology provided a new alternative strategy for the food industry in antimicrobial and preservation.

AI-based processing of future prepared foods: Progress and prospects

The prepared foods sector has grown rapidly in recent years, driven by the fast pace of modern living and increasing consumer demand for convenience. Prepared foods are taking an increasingly important role in the modern catering industry due to their ease of storage, transportation, and operation. However, their processing faces several challenges, including labor shortages, inefficient sorting, inadequate cleaning, unsafe cutting processes, and a lack of industry standards. The development of artificial intelligence (AI) will change the processing of prepared foods. This review summarizes the progress and prospects of AI applications in the sorting/classification, cleaning, cutting, preprocessing, and freezing of prepared foods, encompassing techniques such as mathematical modeling, chemometrics, machine learning, fuzzy logic, and adaptive neuro fuzzy inference system. For example, AI-powered sorting systems using computer vision have improved accuracy in ingredient classification, while deep learning models in cleaning processes have enhanced microbial contamination detection with high spectral imaging techniques. Despite challenges like managing large-scale data and complex models, AI has shown significant potential to inspire both industry practice and research. AI applications can enhance the efficiency, accuracy, and consistency of prepared foods processing, while also reducing labor costs, improving hygiene monitoring, minimizing resource waste, and decreasing environmental impact. Furthermore, AI-driven resource optimization has demonstrated its potential in reducing energy consumption and promoting sustainable food production practices. In the future, AI technology is expected to further improve model generalization and operation precision, driving the food processing industry toward smarter, more sustainable development. This study provides valuable insights to encourage further innovation in AI applications within food processing and technological advancement in the food industry.

Precooked state based on protein denaturation kinetics impacts moisture status, protein oxidation and texture of prepared chicken breast

The quality of meat in prepared dishes deteriorates due to excessive protein denaturation resulting from precooking, freezing, and recooking. This study aimed to link the precooked state with chicken breast's recooked quality. Cooked Value (CV), based on protein denaturation kinetics, was established to indicate the doneness of meat during pre-heating. The effects of CVs after pre-heating on recooked qualities were investigated compared to fully pre-heated samples (control). Mild pre-heating reduced water migration and loss. While full pre-heating inhibited protein oxidation during freezing, intense oxidation during pre-heating led to higher oxidation levels. Surface hydrophobicity analysis revealed that mild pre-heating suppressed aggregation during recooking. These factors contributed to a better texture and microstructure of prepared meat with mild pre-heating. Finally, a potential mechanism of how pre-heating affects final qualities was depicted. This study underlines the need for finely controlling the industrial precooking process to regulate the quality of prepared meat.

Integrating multiple microstructure and water distribution visual analysis to reveal the moisture release and quality deterioration of precooked beef during freezing-thawing-reheating processes

Prepared dishes are becoming an increasingly important part of diets, while most studies focus on the flavor. In this study, the moisture loss induced by structure changes of precooked beef during freezing-thawing-reheating process was investigated. The myowater trapped and released by 'myenteric channels' and 'water reservoir' were observed by integrated multiple microstructure and water distribution visual analysis. X-ray results showed an increase in total porosity and the close porosity transfer to open porosity during freezing-thawing-reheating. The weight loss of frozen-reheated (FR) and frozen-thawed-reheated (FTR) samples was 6.34% and 7.69%, respectively. Although freezing-thawing did not significantly affect the moisture loss, magnetic resonance image (MRI) showed that the 'free water' temporarily existed in interfibrous spaces after thawing and leaked out during reheating. Directly reheating avoided the myowater redistribution and muscle extension mediated, which reduced moisture loss. These results provide a reference for quality control of prepared dishes during the industrial supply chain.

Suppression of Cadra cautella (Lepidoptera: Pyralidae) development by phytosanitary irradiation doses and their impacts on physiochemical and microbiological quality of dates

Cadra cautella is a serious insect pest of stored figs and dates. The irradiation sensitivity of different development stages of C. cautella and large-scale testing of the proposed irradiation quarantine doses (50-500 Gy), were investigated. The impact of a PI dose of 400 Gy on the physiochemical and microbiological quality of dry dates (Bartamoda cv.) stored at room temperature was also investigated. An irradiation dose of 100 Gy prevented egg hatching in the F1 generation when 1-3 days old eggs were irradiated. Irradiation doses of 200 and 300 Gy prevented adult emergence when 2nd and 4th instar larvae were irradiated. When the pupae stage was irradiated, an irradiation dose of 400 Gy prevented the hatchability of F1 generation, indicating that this stage was the most radio-tolerant. The results of large-scale testing of the proposed phytosanitary irradiation dose (400 Gy) applied to 18, 0000 pupae resulted in no reproduction (zero hatching of F1 generation). There were no significant differences in the physiochemical properties of stored dates during the storage period at room temperature. Stable ESR signal intensity was recorded for 6 months in all parts of the irradiated fruits, and the intensity was highest in the kernel. The PI dose of 400 Gy also slightly reduced all microorganisms' counts. In conclusion, the dose level of 400 Gy stopped the reproduction potential of C. cautella. and they maintained the quality characteristics of dry date Bartamoda fruits during storage at room temperature for 6 months in tightly closed packages.

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.

Exploring public opinion on health effects of prepared dishes in China through social media comments

Introduction

In the 2020s, particularly following 2022, the Chinese government introduced a series of initiatives to foster the development of the prepared dishes sector, accompanied by substantial investments from industrial capital. Consequently, China's prepared dishes industry has experienced rapid growth. Nevertheless, this swift expansion has elicited varied public opinions, particularly concerning the potential health effects of prepared dishes. Therefore, this study aims to gather and analyze comments from social media on prepared dishes using machine learning techniques. The objective is to ascertain the perspectives of the Chinese populace on the health implications of consuming prepared dishes.

Methods

Social media comments, characterized by their broad distribution, objectivity, and timeliness, served as the primary data source for this study. Initially, the data underwent preprocessing to ensure its suitability for analysis. Subsequent steps in this study involved conducting sentiment analysis and employing the BERTopic model for topic clustering. These methods aimed to identify the principal concerns of the public regarding the impact of prepared dishes on health. The final phase of the study involved a comparative analysis of changes in public sentiment and thematic focus across different time frames. This approach provides a dynamic view of evolving public perceptions related to the health implications of prepared dishes.

Results

This study analyzed over 600,000 comments gathered from various social media platforms from mid-July 2022 to the end of March 2024. Following data preprocessing, 200,993 comments were assessed for sentiment, revealing that more than 64% exhibited negative emotions. Subsequent topic clustering using the BERTopic model identified that 11 of the top 50 topics were related to public health concerns. These topics primarily scrutinized the safety of prepared dish production processes, raw materials, packaging materials, and additives. Moreover, significant public's interest was in the right to informed consumption across different contexts. Notably, the most pronounced public opposition emerged regarding introducing prepared dishes into primary and secondary school canteens, with criticisms directed at the negligence of educational authorities and the ethics of manufacturers. Additionally, there were strong recommendations for media organizations to play a more active role in monitoring public opinion and for government agencies to enhance regulatory oversight.

Conclusion

The findings of this study indicate that more than half of the Chinese public maintain a negative perception towards prepared dishes, particularly concerning about health implications. Chinese individuals display considerable sensitivity and intense reactions to news and events related to prepared dishes. Consequently, the study recommends that manufacturers directly address public psychological perceptions, proactively enhance production processes and service quality, and increase transparency in public communications to improve corporate image and people acceptance of prepared dishes. Additionally, supervisory and regulatory efforts must be intensified by media organizations and governmental bodies, fostering the healthy development of the prepared food industry in China.

Perspectives on Novel Technologies of Processing and Monitoring the Safety and Quality of Prepared Food Products

With the changes of lifestyles and rapid growth of prepared food industry, prepared fried rice that meets the consumption patterns of contemporary young people has become popular in China. Although prepared fried rice is convenient and nutritious, it has the following concerns in the supply chain: (1) susceptible to contamination by microorganisms; (2) rich in starch and prone to stall; and (3) vegetables in the ingredients have the issues of water loss and discoloration, and meat substances are vulnerable to oxidation and deterioration. As different ingredients are used in prepared fried rice, their food processing and quality monitoring techniques are also different. This paper reviews the key factors that cause changes in the quality of prepared fried rice, and the advantages and limitations of technologies in the processing and monitoring processes. The processing technologies for prepared fried rice include irradiation, high-voltage electric field, microwave, radio frequency, and ohmic heating, while the quality monitoring technologies include Raman spectral imaging, near-infrared spectral imaging, and low-field nuclear magnetic resonance technology. These technologies will serve as the foundation for enhancing the quality and safety of prepared fried rice and are essential to the further development of prepared fried rice in the emerging market.

Novel strategies for controlling nitrite content in prepared dishes: Current status, potential benefits, limitations and future challenges

Sodium nitrite is commonly used as a multifunctional curing ingredient in the processing of prepared dishes, especially meat products, to impart unique color, flavor and to prolong the shelf life of such products. However, the use of sodium nitrite in the meat industry has been controversial due to potential health risks. Finding suitable substitutes for sodium nitrite and controlling nitrite residue have been a major challenge faced by the meat processing industry. This paper summarizes possible factors affecting the variation of nitrite content in the processing of prepared dishes. New strategies for controlling nitrite residues in meat dishes, including natural pre-converted nitrite, plant extracts, irradiation, non-thermal plasma and high hydrostatic pressure (HHP), are discussed in detail. The advantages and limitations of these strategies are also summarized. Raw materials, cooking techniques, packaging methods, and storage conditions all affect the content of nitrite in the prepared dishes. The use of vegetable pre-conversion nitrite and the addition of plant extracts can help reduce nitrite residues in meat products and meet the consumer demand for clean labeled meat products. Atmospheric pressure plasma, as a non-thermal pasteurization and curing process, is a promising meat processing technology. HHP has good bactericidal effect and is suitable for hurdle technology to limit the amount of sodium nitrite added. This review is intended to provide insights for the control of nitrite in the modern production of prepared dishes.

Technological innovations enhance postharvest fresh food resilience from a supply chain perspective

Fresh food is rich in nutrients but is usually seasonal, perishable, and challenging to store without degradation of quality. The inherent limitations of various preservation technologies can result in losses in all stages of the supply chain. As consumers of fresh foods have become more health-conscious, new technologies for intelligent, energy-efficient, and nondestructive preservation and processing have emerged as a research priority in recent years. This review aims to summarize the quality change characteristics of postharvest fruits, vegetables, meats, and aquatic products. It critically analyzes research progress and applications of various emerging technologies, which include: the application of high-voltage electric field, magnetic field, electromagnetic field, plasma, electrolytic water, nanotechnology, modified atmosphere packaging, and composite bio-coated film preservation technologies. An evaluation is presented of the benefits and drawbacks of these technologies, as well as future development trends. Moreover, this review provides guidance for design of the food supply chain to take advantage of various technologies used to process food, reduce losses and waste of fresh food, and this improve the overall resilience of the supply chain.

Construction of interfacial crystallized oleogel emulsion with improved thermal stability

In this study, we reported a facile strategy to produce an interfacial crystallized oleogel emulsion for improved thermal stability. The interfacial crystallization of ceramide (non-interfacial active oleogelator) was achieved by addition of a surface active compound, which was demonstrated by interfacial rheology tests and polarized light microscopy. For successfully prepared interfacial crystallized emulsions, smaller particle size was observed when the gelator concentration was lower. However, better thermal stability was achieved when oleogelator concentration was higher than 1 wt%. Results from differential scanning calorimetry, X-ray diffraction and Fourier transform infrared spectroscopy suggested that the interfacial adsorption of ceramide was due to its co-crystallization with the emulsifier driven by hydrogen bonds formed by multiple sites. It provided appropriate crystallinity and steric repulsion for oleogel emulsions against oil droplet coalescence during heating process. This strategy greatly enriches oleogel emulsion formulations and their potential applications in food products involved with thermal treatment.

Advances in prepared dish processing using efficient physical fields: A review

Prepared dishes are increasingly popular convenience food that can be eaten directly from hygienic packaging by heating. Physics field (PF) is food processing method built with physical processing technology, which has the characteristics of high efficiency and environmental safety. This review focuses on summarizing the application of PFs in prepared dishes, evaluating and comparing PFs through quality changes during processing and storage of prepared dishes. Currently, improving the quality and extending the shelf life of prepared dishes through thermal and non-thermal processing are the main modes of action of PFs. Most PFs show good potential in handing prepared dishes, but may also react poorly to some prepared dishes. In addition, the difficulty of precise control of processing conditions has led to research mostly at the laboratory stage, but as physical technology continues to break through, more PFs and multi-physical field will be promoted for commercial use in the future. This review contributes to a deeper understanding of the effect of PFs on prepared dishes, and provides theoretical reference and practical basis for future processing research in the development of various enhanced PFs.

Application of sonodynamic technology and sonosensitizers in food sterilization: a review of developments, trends and challenges

Food safety and food waste have always been hot topics of discussion in recent years. However, the infection of human pathogenic bacteria and the waste of food resources caused by microbial-contaminated food remains common. Although traditional sterilization technology has been very mature, it causes changes in food flavor and excessive energy consumption to a certain extent. Moreover, the widespread bacterial resistance has also sounded a warning for researchers and finding a new alternative to antibiotics is urgently needed. The application of sonodynamic sterilization technology in medical treatment has aroused the interest of researchers. It provides ideas for new food sterilization technology. As a new non-thermal sterilization technology, sonodynamic sterilization technology has strong penetration, safety, less residue and by-products, and will less change the quality of the food itself. Therefore, sonodynamic sterilization technology has great potential applied in food sterilization technology. This review describes the concept of sonodynamic sterilization technology, the sterilization mechanism of sonodynamic sterilization and the inactivation mechanism of various pathogens, the classification and application of sonosensitizers, and the ultrasonic technology in sonodynamic sterilization in the application over the recent years. It provides a scientific reference for the application of sonodynamic sterilization technology in the field of food sterilization.

Consumer Attitudes towards Food Preservation Methods

The development and scope of using various food preservation methods depends on the level of consumers’ acceptance. Despite their advantages, in the case of negative attitudes, producers may limit their use if it determines the level of sales. The aim of this study was to evaluate the perception of seven different food processing methods and to identify influencing factors, such as education as well as living area and, at the same time, to consider whether consumers verify this type of information on the labels. Additionally, the study included the possibility of influencing consumer attitudes by using alternative names for preservation methods, on the example of microwave treatment. The results showed that conventional heat treatments were the most preferred preservation methods, whereas preservatives, irradiation, radio waves and microwaves were the least favored, suggesting that consumers dislike methods connected with “waves” to a similar extent as their dislike for preservatives. The control factors proved to significantly modify the evaluation of the methods. The analysis of alternative names for microwave treatment showed that “dielectric heating” was significantly better perceived. These research findings are important as the basis for understanding consumer attitudes. Implications for business and directions of future research are also indicated.

Role of dehydration technologies in processing for advanced ready-to-eat foods: A comprehensive review

Advanced ready-to-eat foods, which can be consumed directly or only need simple processed before consumption, refer to the products that processing with cutting-edge food science and technology and have better quality attribute. Cold chain and chemical addition are commonly used options to ensure microbial safety of high moisture advanced ready-to-eat foods. However, this requires freezing/thawing processing at high cost or has undesirable residue. Dehydration treatment has the potential to compensate those shortcomings. This article reviewed the positive effects of dehydration on advanced ready-to-eat foods, current application status of dehydration technologies, novel dehydration related technologies and the pathogenic bacteria control of products. It is observed that dehydration treatment is receiving increasing attention for ready-to-eat foods including space foods, 3 D-printed personalized foods and formula foods for special medical purposes. Recently developed drying technologies such as pulsed spouted microwave freeze-drying and infrared freeze-drying have attracted much interest due to their excellent drying characteristics. Finally, intelligent drying, dehydration-nano-hybridization and dehydration-induced multi-dimensional modification technology are some of the emerging R and D areas in this field.

Invited review: Stress resistance of Cronobacter spp. affecting control of its growth during food production

Members of the Cronobacter genus include food-borne pathogens that can cause infections in infants, with a mortality rate as high as 40 to 80%. The high fatality rate of Cronobacter and its isolation from numerous types of food, especially from powdered infant formula, demonstrate the serious nature of this organism. The source tracking of Cronobacter spp. and the analysis of high-frequency species from different sources are helpful for a more targeted control. Furthermore, the persistence during food processing and storage may be attributed to strong resistance of Cronobacter spp. to environment stresses such as heat, pH, and desiccation. There are many factors that support the survival of Cronobacter spp. in harsh environments, such as some genes, regulatory systems, and biofilms. Advanced detection technology is helpful for the strict monitoring of Cronobacter spp. In addition to the traditional heat treatment, many new control techniques have been developed, and the ability to control Cronobacter spp. has been demonstrated. The control of this bacteria is required not only during manufacture, but also through the selection of packaging methods to reduce postprocessing contamination. At the same time, the effect of inactivation methods on product quality and safety must be considered. This review considers the advances in our understanding of environmental stress response in Cronobacter spp. with special emphasis on its implications in food processing.

UPLC/MS-based untargeted metabolomics reveals the changes in muscle metabolism of electron beam irradiated Solenocera melantho during refrigerated storage

Shrimp meat is an extremely perishable product; however, refrigeration can slow down spoilage. In this study, we used electron beam irradiation (EBI) to pre-treat shrimp meat and analyzed the metabolites of the treated shrimp meat during refrigerated storage using metabonomic analysis methods. In total, 4865 metabolites were identified, of which, 103 differential metabolites had KEGG (Kyoto Encyclopedia of Genes and Genomes) IDs. Further, two potential biomarkers were obtained. Based on the results, l-lysine was downregulated, while 2'-deoxyguanosine 5'-monophosphate and dihydroxyacetone phosphate acyl ester were upregulated during the refrigerated storage. The metabolic activity began to weaken gradually after 9 days. However, the different metabolites related to EBI were not identified herein. Nonetheless, the study findings revealed the metabolic changes in Solenocera melantho at the molecular level during refrigerated storage after EBI.

Effect of ionising irradiation on silver release from polyolefin/silver nanocomposite films into food simulants

Two types of nanocomposite films, polyethylene/silver (PE/Ag) and polypropylene/silver (PP/Ag), were prepared and characterised. Assessment of silver released under the effect of ionising irradiation was performed on the nanocomposite films. The release experiment was carried out by immersing the nanocomposite films in water, 3% acetic acid or 95% ethanol as food simulants and measuring the Ag release from nanocomposite films treated with and without gamma or electron beam irradiation at a dose of 10 kGy. In general, irradiation treatment increased the Ag release regardless of the type of polymer and food simulant. One reason could be radiation-induced metal oxidation at the surface which in turn promoted ion release into food simulants. The oxidising radicals produced by radiation in solution could be another factor speeding up metal oxidation and subsequent ion release. When comparisons were made between the two types of irradiation, greater Ag release into water and 3% acetic acid was observed after electron beam irradiation, while gamma irradiation was likely to induce greater Ag release into 95% ethanol. Such phenomena reveal the influence of different types of radiation on the solutions which in turn affect the Ag release.

Effect of E-beam treatment on expression of virulence and stress-response genes of Listeria monocytogenes in dry-cured ham

Various adverse conditions can trigger defensive mechanisms in Listeria monocytogenes that can increase the virulence of surviving cells. The objective of this study was to evaluate the expression of one stress-response (sigB) and three virulence (plcA, hly, and iap) genes in L. monocytogenes exposed to a sub lethal dose of E-beam irradiation in dry-cured ham. To accomplish this, dry-cured ham slices (10 g) were immersed in a 10⁹ CFU/mL suspension of L. monocytogenes strain S4-2 and subsequently irradiated with 1, 2, or 3 kGy. After irradiation, samples were stored at 7 °C or 15 °C for 30 days. Absolute gene expression levels were determined by RT-qPCR, and numbers of surviving Listeria cells were assessed by microbial counts after different storage times (0, 7, 15, and 30 days). At 7 °C, after E-beam treatment at doses of 2 or 3 kGy, Listeria gene expression significantly increased (p ≤ 0.05) up to day 15. Listeria counts decreased with increasing dosage. The relationship between absolute gene expression and the number of surviving Listeria cells could indicate that sublethal doses of E-beam irradiation can increase expression of the genes studied. We observed no significant influence of storage time or temperature on gene expression (p > 0.05). Listeria that survives E-beam treatment may display increased virulence, constituting a significant potential public health risk.

pH interferes in photoinhibitory activity of curcumin nanoencapsulated with pluronic® P123 against Staphylococcus aureus

Microbial contamination control is a public health concern and challenge for the food industry. Antimicrobial technologies employing natural agents may be useful in the food industry for these purposes. This work aimed to investigate the effect of photodynamic inactivation using curcumin in Pluronic® P123 nanoparticles (Cur/P123) at different pH and blue LED light against Staphylococcus aureus. Bacterial photoinactivation was conducted using different photosensitizer concentrations and exposure times at pH 5.0, 7.2 and 9.0. A mixture design was applied to evaluate the effects of exposure time (dark and light incubation) on the photoinhibitory effect. S. aureus was completely inactivated at pH 5.0 by combining low concentrations of Cur/P123 (7.80-30.25 μmol/L) and light doses (6.50-37.74 J/cm²). According to the mathematical model, dark incubation had low significance in bacterial inactivation at pH 5.0 and 9.0. No effect in bacterial inactivation was observed at pH 7.2. Cur/P123 with blue LED was effective in inactivating S. aureus. The antimicrobial effect of photodynamic inactivation was also pH-dependent.

Foodborne Viruses and Innovative Non-Thermal Food-Processing Technologies

In recent years, several foodborne viruses' outbreaks have been recorded worldwide. Μost of the foodborne viruses have a low infection dose, are stable and can persist and survive in foods for a long time without loss of infectivity. The most important foodborne viruses are: human norovirus (HuNoV), human rotavirus (HRV), hepatitis A virus (HAV), hepatitis E virus (HEV), human astrovirus (HAstV), Aichi virus (AiV), sapovirus (SaV), human adenovirus (HAdV) and enterovirus (EV). In recent years, innovative non-thermal food-processing technologies including high-pressure processing (HPP), cold plasma (CP), ultraviolet light (UV), irradiation and pulsed electric field (PEF) for improving the quality and safety of foods, including foods of animal origin, have been under research. This review presents the recent data on foodborne viruses and reviews the innovative non-thermal technologies for the control of the foodborne viruses in foods.