Wholesomeness and safety aspects of irradiated foods

Irradiation technology: An effective and promising strategy for eliminating food allergens

Food allergies are one of the major health concerns worldwide and have been increasing at an alarming rate in recent times. The elimination of food allergenicity has been an important issue in current research on food. Irradiation is a typical nonthermal treatment technology that can effectively reduce the allergenicity of food, showing great application prospects in improving the quality and safety of foods. In this review, the mechanism and remarkable features of irradiation in the elimination of food allergens are mainly introduced, and the research progress on reducing the allergenicity of animal foods (milk, egg, fish and shrimp) and plant foods (soybean, peanut, wheat and nuts) using irradiation is summarized. Furthermore, the influencing factors for irradiation in the elimination of food allergens are analyzed and further research directions of irradiation desensitization technology are also discussed. This article aims to provide a reference for promoting the application of irradiation technology in improving the safety of foods.

Effect of gamma radiation on microbial load, physico-chemical and sensory characteristics of common spices for storage

The effect of gamma radiation on the decontamination of microbial population, physico-chemical, radiation sensitivity and sensory characteristics of common spices for storage were evaluated. Spices were irradiated with gamma doses of 0 (as control), 2, 4, 6, 8 and 10 kGy, packed in the glass vials and stored at room temperature (22 ± 2°C) in the laboratory. In this research, Bacillus, Salmonella and Listeria species were identified in un-irradiated spice samples. Results also indicated that gamma radiation reduced the total microbial population compared to control and optimum gamma radiation doses (6 kGy for red chili and turmeric; 4 kGy for cumin, coriander, garlic and black pepper; 2 kGy for ginger powder samples) were identified for decontamination of the organisms in the studied spices. It was concluded that no significant differences before and after gamma radiation were observed in physico-chemical, nutritional and sensory properties but significantly changed in microbial load in spices samples.

The Threshold Effects of Low-Dose-Rate Radiation on miRNA-Mediated Neurodevelopment of Zebrafish

The biological effects and regulatory mechanisms of low-dose and low-dose-rate radiation are still rather controversial. Therefore, in this study we investigated the effects of low-dose-rate radiation on zebrafish neurodevelopment and the role of miRNAs in radiation-induced neurodevelopment. Zebrafish embryos received prolonged gamma-ray irradiation (0 mGy/h, 0.1 mGy/h, 0.2 mGy/h, 0.4 mGy/h) during development. Neurodevelopmental indicators included mortality, malformation rate, swimming speed, as well as the morphology changes of the lateral line system and brain tissue. Additionally, spatiotemporal expression of development-related miRNAs (dre-miR-196a-5p, dre-miR-210-3p, dre-miR-338) and miRNA processing enzymes genes (Dicer and Drosha) were assessed by qRT-PCR and whole mount in situ hybridization (WISH). The results revealed a decline in mortality, malformation and swimming speed, with normal histological and morphological appearance, in zebrafish that received 0.1 mGy/h; however, increased mortality, malformation and swimming speed were observed, with pathological changes, in zebrafish that received 0.2 mGy/h and 0.4 mGy/h. The expression of miRNA processing enzyme genes was altered after irradiation, and miRNAs expression was downregulated in the 0.1 mGy/h group, and upregulated in the 0.2 mGy/h and 0.4 mGy/h groups. Furthermore, ectopic expression of dre-miR-210-3p, Dicer and Drosha was also observed in the 0.4 mGy/h group. In conclusion, the effect of low-dose and low-dose-rate radiation on neurodevelopment follows the threshold model, under the regulation of miRNAs, excitatory effects occurred at a dose rate of 0.1 mGy/h and toxic effects occurred at a dose rate of 0.2 mGy/h and 0.4 mGy/h.

Isolation and Characterization of a Novel Salmonella Phage vB_SalP_TR2

Salmonella is a widely distributed foodborne pathogen. The use of Salmonella phages as biocontrol agents has recently gained significant interest. Because the Salmonella genus has high diversity, efforts are necessary to identify lytic Salmonella phages focusing on different serovars. Here, five Salmonella phages were isolated from soil samples, and vB_SalP_TR2 was selected as a novel phage with high lytic potential against the host Salmonella serovar Albany, as well as other tested serovars, including Corvallis, Newport, Kottbus, and Istanbul. Morphological analyses demonstrated that phage vB_SalP_TR2 belongs to the Podoviridae family, with an icosahedral head (62 ± 0.5 nm in diameter and 60 ± 1 nm in length) and a short tail (35 ± 1 nm in length). The latent period and burst size of phage vB_SalP_TR2 was 15 min and 211 PFU/cell, respectively. It contained a linear dsDNA of 71,453 bp, and G + C content was 40.64%. Among 96 putative open reading frames detected, only 35 gene products were found in database searches, with no virulence or antibiotic resistance genes being identified. As a biological control agent, phage vB_SalP_TR2 exhibited a high temperature and pH tolerance. In vitro, it lysed most S. Albany after 24 h at 37°C with multiplicities of infection of 0.0001, 0.001, 0.01, 0.1, 1, 10, and 100. In food matrices (milk and chicken meat), treatment with phage vB_SalP_TR2 also reduced the number of S. Albany compared with that in controls. These findings highlighted phage vB_SalP_TR2 as a potential antibacterial agent for the control of Salmonella in food samples.

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.

Electron Beam Susceptibility of Enteric Viruses and Surrogate Organisms on Fruit, Seed and Spice Matrices

The objective of this study was to use high-energy electron beam (HEEB) treatments to find surrogate microorganisms for enteric viruses and to use the selected surrogates as proof of concept to investigate low-energy electron beam (LEEB) treatments for enteric virus inactivation at industrial scale on frozen blueberries. Six food matrices inoculated with HAV (hepatitis A virus), MNV S99 (murine norovirus), bacteriophages MS2 and Qβ, and Geobacillus stearothermophilus spores were treated with HEEB at 10 MeV using 4, 8 and 16 kGy doses. G. stearothermophilus spores showed the highest inactivation on all matrices except on raisins, with a dose-dependent effect. HAV reached the maximum measurable log₁₀ reduction (> 3.2 log₁₀) when treated at 16 kGy on raisins. MNV showed the highest resistance of all tested microorganisms, independent of the dose, except on frozen blueberries. On frozen blueberries, freeze-dried raspberries, sesame seeds and black peppercorns, HAV showed a mean inactivation level in between those of MS2 and G. stearothermophilus. Based on this, we selected both surrogate organisms as first approximation to estimate HAV inactivation on frozen blueberries during LEEB treatment at 250 keV using 16 kGy. Reductions of 3.1 and 1.3 log₁₀ were measured for G. stearothermophilus spores and MS2, respectively, suggesting that a minimum reduction of 1.4 log₁₀ can be expected for HAV under the same conditions.

Microwave applications in the food industry: an overview of recent developments

Microwave radiation has the ability to heat a material with dielectric properties. Material absorbs microwave energy and then converts it into heat, which gives the possibility of a wide use of microwaves in many industry sectors or agricultural sciences. Microwaves are especially widely used in food industry. The main objective of this paper is to present an overview of recent development regarding microwave applications in food industry. Many techniques in food processing (pasteurization, sterilization, drying, thawing, blanching and stunning) are assisted by microwave energy. It should be mentioned also the use of microwaves in nutrients and nutraceuticals production. Waste generation is an integral part of food production. Microwaves have also application in wastes management. The results of experiments, factors affecting heating and their practical application have been discussed. Many cases have been compared with conventional process methods. The use of microwaves shows many advantages. The most important aspect is shortening the time of the thermal process (even by 50%) and reducing the costs of the operation. In addition, it allows to increase the efficiency of processes while maintaining high quality. The examples of microwave applications given in the article are environmentally- friendly because the conditions of thermal processing allow for reducing the use of solvents and the amount of sewage by decreasing the demand for water. It is anticipated that microwaves will become increasingly popular, with the development of new microwave technologies solving many problems in the future.

Chemical Composition of Magonia pubescens Essential Oils and Gamma-Radiation Effects on Its Constituents and Cytotoxic Activity in Leukemia and Breast Cancer Model

Magonia pubescens A. St.-Hil. is a Brazilian species often used in ethnopharmacology for wound and pain healing and seborrhea treatment. For the first time, essential oils (EOs) obtained from M. pubescens inflorescences were studied. The plant materials (Montes Claros, Brazil, 2018) were submitted to different gamma-radiation doses and their chemical compositions were analyzed by GC/MS and GC-FID. The cytotoxic activity of the EOs was evaluated against K562 and MDA-MB-231 cancer cell lines. A total of 30 components were identified, being 24 compounds detected for the first time in M. pubescens. The main obtained components were hotrienol (35.9 %), cis-linalool oxide (17.0 %) and trans-linalool oxide (10.2 %). The chemical composition of the EO was slightly affected by the applied radiation doses. Irradiated and non-irradiated EOs showed cytotoxic activity against both cell lines and the non-irradiated EO sample was the most active against the K562 cell lines (IC₅₀ =22.10±1.98).

Effect of irradiation treatment on the lipid composition and nutritional quality of goat meat

The knowledge of the changes in the lipid species in irradiated goat meat is expected to clarify the beneficial effects of irradiation on meat preservation. This study explored the characteristic lipid composition and the changes in irradiated goat meat based on quantitative lipidomics strategy by LC-MS. Totally, 12 subclasses of 174 lipids were identified with significant differences (p < 0.05, VIP > 1), and the absolute quantitative analysis of characteristic lipids was achieved. Significant lipid variables were involved in the major pathways of glycerophospholipid and sphingolipid metabolism. Moreover, significant increases during irradiation were found in total TG, PC, PE, LPE, Cer, LPC and SPH, while the total DG, PS, PG, PI and SM decreased after irradiation. Noteworthily, DHA-enriched PC (18:4/22:6) + H, a core nutrient for human health, exhibited an increase in the irradiated group. These results provide a basis for lipid quantitative alterations in irradiated goat meat and application of irradiation in meat preservation.

Quantifying the impact of eight unit operations on the survival of eight Bacillus strains with claimed probiotic properties

This study assessed the impact of eight unit operations [slow pasteurization, high-temperature short time (HTST) pasteurization, cooking, baking, drying, fermentation, supercritical carbon dioxide (CO₂), irradiation and extrusion] in different food matrices (milk, orange juice, meatballs, bread, crystallized pineapple, yogurt, orange juice, ground black pepper, snacks, and spaghetti) on the resistance of eight (Bacillus flexus Hk1 Bacillus subtilis Bn1, Bacillus licheniformis Me1, Bacillus mojavensis KJS3, Bacillus subtilis PXN21, Bacillus subtilis PB6, Bacillus coagulans MTCC 5856 and Bacillus coagulans GBI-30, 6086) Bacillus strains with claimed probiotic properties (PB). The number of decimal reductions (γ) caused by the unit operations varied (p < 0.05) amongst the PB. Most of the unit operations caused ≤ 2 γ of PB in the food matrices evaluated. Irradiation caused up to 4.9 γ (p < 0.05) amongst the PB tested. B. subtilis Bn1, B. mojavensis KJS3, B. licheniformis Me1, and B. coagulans GBI-30 showed higher resistance to most of the tested unit operations. These results indicate that the choice of PB for application in foods should also be based on their resistance to unit operations employed during processing. Finally, the high resistance of PB to the unit operations tested comprise valuable data for the development and diversification of probiotic foods with sporeforming strains with claimed probiotic properties.

Effective pretreatment technologies for fresh foods aimed for use in central kitchen processing

The central kitchen concept is a new trend in the food industry, where centralized preparation and processing of fresh foods and the distribution of finished or semi-finished products to catering chains or related units take place. Fresh foods processed by a central kitchen mainly include fruit and vegetables, meat, aquatic products, and edible fungi; these foods have high water activities and thermal sensitivities and must be processed with care. Appropriate pretreatments are generally required for these food materials; typical pretreatment processes include cleaning, enzyme inactivation, and disinfection, as well as packaging and coating. To improve the working efficiency of a central kitchen, novel efficient pretreatment technologies are needed. This article systematically reviews various high-efficiency pretreatment technologies for fresh foods. These include ultrasonic cleaning technologies, physical-field enzyme inactivation technologies, non-thermal disinfection technologies, and modified-atmosphere packagings and coatings. Mechanisms, applications, influencing factors, and advantages and disadvantages of these technologies, which can be used in a central kitchen, are outlined and discussed. Possible solutions to problems related to central-kitchen food processing are addressed, including low cleaning efficiency and automation feasibility, high nutrition loss, high energy consumption, and short shelf life of products. These should lead us to the next step of fresh food processing for a highly demanding modern society. © 2020 Society of Chemical Industry.

A review of bacterial biofilm control by physical strategies

Biofilms are multicellular communities of microorganisms held together by a self-produced extracellular matrix, which contribute to hygiene problems in the food and medical fields. Both spoilage and pathogenic bacteria that grow in the complex structure of biofilm are more resistant to harsh environmental conditions and conventional antimicrobial agents. Therefore, it is important to develop eco-friendly preventive methodologies to eliminate biofilms from foods and food contact equipment. The present paper gives an overview of the current physical methods for biofilm control and removal. Current physical strategies adopted for the anti-biofilm treatment mainly focused on use of ultrasound power, electric or magnetic field, plasma, and irradiation. Furthermore, the mechanisms of anti-biofilm action and application of different physical methods are discussed. Physical strategies make it possible to combat biofilm without the use of biocidal agents. The remarkable microbiocidal properties of physical strategies are promising tools for antimicrobial applications.

Food preservation techniques and nanotechnology for increased shelf life of fruits, vegetables, beverages and spices: a review

Food wastage is a major issue impacting public health, the environment and the economy in the context of rising population and decreasing natural resources. Wastage occurs at all stages from harvesting to the consumer, calling for advanced techniques of food preservation. Wastage is mainly due to presence of moisture and microbial organisms present in food. Microbes can be killed or deactivated, and cross-contamination by microbes such as the coronavirus disease 2019 (COVID-19) should be avoided. Moisture removal may not be feasible in all cases. Preservation methods include thermal, electrical, chemical and radiation techniques. Here, we review the advanced food preservation techniques, with focus on fruits, vegetables, beverages and spices. We emphasize electrothermal, freezing and pulse electric field methods because they allow both pathogen reduction and improvement of nutritional and physicochemical properties. Ultrasound technology and ozone treatment are suitable to preserve heat sensitive foods. Finally, nanotechnology in food preservation is discussed.

American Cancer Society guideline for diet and physical activity for cancer prevention

The American Cancer Society (ACS) publishes the Diet and Physical Activity Guideline to serve as a foundation for its communication, policy, and community strategies and, ultimately, to affect dietary and physical activity patterns among Americans. This guideline is developed by a national panel of experts in cancer research, prevention, epidemiology, public health, and policy, and reflects the most current scientific evidence related to dietary and activity patterns and cancer risk. The ACS guideline focuses on recommendations for individual choices regarding diet and physical activity patterns, but those choices occur within a community context that either facilitates or creates barriers to healthy behaviors. Therefore, this committee presents recommendations for community action to accompany the 4 recommendations for individual choices to reduce cancer risk. These recommendations for community action recognize that a supportive social and physical environment is indispensable if individuals at all levels of society are to have genuine opportunities to choose healthy behaviors. This 2020 ACS guideline is consistent with guidelines from the American Heart Association and the American Diabetes Association for the prevention of coronary heart disease and diabetes as well as for general health promotion, as defined by the 2015 to 2020 Dietary Guidelines for Americans and the 2018 Physical Activity Guidelines for Americans.

Managing the risk of Vibrio parahaemolyticus infections associated with oyster consumption: A review

Vibrio parahaemolyticus is a Gram-negative bacterium that is naturally present in the marine environment. Oysters, which are water filter feeders, may accumulate this pathogen in their soft tissues, thus increasing the risk of V. parahaemolyticus infection among people who consume oysters. In this review, factors affecting V. parahaemolyticus accumulation in oysters, the route of the pathogen from primary production to consumption, and the potential effects of climate change were discussed. In addition, intervention strategies for reducing accumulation of V. parahaemolyticus in oysters were presented. A literature review revealed the following information relevant to the present study: (a) managing the safety of oysters (for human consumption) from primary production to consumption remains a challenge, (b) there are multiple factors that influence the concentration of V. parahaemolyticus in oysters from primary production to consumption, (c) climate change could possibly affect the safety of oysters, both directly and indirectly, placing public health at risk, (d) many intervention strategies have been developed to control and/or reduce the concentration of V. parahaemolyticus in oysters to acceptable levels, but most of them are mainly focused on the downstream steps of the oyster supply chain, and (c) although available regulation and/or guidelines governing the safety of oyster consumption are mostly available in developed countries, limited food safety information is available in developing countries. The information provided in this review may serve as an early warning for managing the future effects of climate change on the safety of oyster consumption.

Effects of electron beam irradiation on the properties of waxy maize starch and its films

Waxy maize starch was irradiated under different doses of radiation (2-30 kGy), and starch physicochemical properties were analysed. Films were subsequently produced from native and irradiated waxy maize starches and their properties were tested. The starch molecular weight markedly decreased with increasing irradiation dose. And the branch chain length, melting temperature, melting enthalpy, and relative crystallinity decreased slightly, especially at an irradiation dose below 15 kGy. This indicated that more α-1,6-glucosidic bonds than α-1,4-glucosidic bonds were cleaved by a low dose of irradiation; hence, more linear chains were released. Films prepared from 10 kGy irradiated waxy maize starch displayed enhanced mechanical properties and increased solubility, owing to a moderate increase in linear starch chains and a decrease in starch molecular weight, respectively. The resulting rapidly-dissolvable films from irradiated waxy maize starch have potential for use in instant food packaging.

Practical analysis of aflatoxin M1 reduction in pasteurized Milk using low dose gamma irradiation

Milk and dairy products can be exposed to potential dangers such as aflatoxin M1 (AFM1). Various factors affect the formation of aflatoxin, which can be due to environmental changes and the lack of suitable substrate for healthy livestock feeding. The goal of this study is to reduce the toxin in pasteurized milk to a level below the European Codex Alimentarius Commission standard. For this purpose, the proper structure of the radioactive granite stone was first designed as a low level gamma irradiation (LLGI) without contact with pasteurized milk, and and the pasteurized milk containing AFM1 that placed in this structure is measured and compared with the control sample values using Association of Official Analytical Chemists (AOAC) method. Then, the reduction of the resulting aflatoxin in the milk and the LLGI dose rate are obtained. The LLGI dose rate is calculated using the Monte Carlo N-Particle Transport Code (MCNP). For simulation, in addition to the spectrum of gamma radiation emitted by radioactive granites, weight percent of each composition of the pasteurized milk and its component elements are also calculated. The results showed a 51.5% reduction of aflatoxin in pasteurized milk after 4 days and 99% reduction after 8 days compared to the control sample. The LLGI dose rate in milk is 0.39 mGy per day. According to the international atomic energy agency (IAEA) report and pervious results, this dose rate level does not significantly affect chemical and sensory quality of milk, but can extend the shelf-life and provide a safer milk. Therefore, the structure constructed using radioactive granite in this study can be considered as one of the suitable methods for reducing aflatoxin.

Combined use of eBeam irradiation and the potential probiotic Lactobacillus rhamnosus Vahe for control of foodborne pathogen Klebsiella pneumoniae

Purpose

The implementation of electron beam radiation coupled with the use of probiotics is one of the newest food processing technologies that may be used to ensure food safety and improve shelf life of food products. The purpose of this study was to evaluate the effect of 50–150-Gy electron beam irradiation on the antimicrobial activity of the putative probiotic strain Lactobacillus rhamnosus Vahe.

Methods

Low-dose electron beam irradiation of lactobacilli cells was performed using the Advanced Research Electron Accelerator Laboratory’s electron accelerator, and the agar well diffusion method and Verhulst logistic function were used to evaluate the effect of radiation on anti–Klebsiella pneumoniae activity of the cell free supernatant of L. rhamnosus Vahe cells in vitro.

Results

Our results suggest that 50–150-Gy electron beam irradiation decreases the viability of the investigated lactobacilli, but does not significantly change the probiotic’s activity against K. pneumoniae.

Conclusions

Results indicate that the combined use of irradiation and L. rhamnosus Vahe might be suggested for non-thermal food sterilizing technologies.