Ultraviolet radiation: An interesting technology to preserve quality and safety of milk and dairy foods

Campylobacter control strategies at postharvest level

Campylobacter is highly associated with poultry and frequently causes foodborne illness worldwide. Thus, effective control measures are necessary to reduce or prevent human infections. In this review, Campylobacter control methods applicable at postharvest level for poultry meat during production, storage, and preparation are discussed. Drying and temperature are discussed as general strategies. Traditional strategies such as steaming, freezing, sanitizing, organic acid treatment, and ultraviolet light treatment are also discussed. Recent advances in nanotechnology using antibacterial nanoparticles and natural antimicrobial agents from plants and food byproducts are also discussed. Although advances have been made and there are various methods for preventing Campylobacter contamination, it is still challenging to prevent Campylobacter contamination in raw poultry meats with current methods. In addition, some studies have shown that large strain-to-strain variation in susceptibility to these methods exists. Therefore, more effective methods or approaches need to be developed to substantially reduce human infections caused by Campylobacter.

Design and Characterization of Liposomal-Based Carriers for the Encapsulation of Rosa canina Fruit Extract: In Vitro Gastrointestinal Release Behavior

The increasing demand for natural compounds as an alternative to synthetic antioxidants and conservans has led to the utilization of secondary plant metabolites in the food industry, as these bioactive compounds possess great antioxidative and antimicrobial properties without side effects on human health. Despite this, the sensitivity of plant-derived compounds is a restrictive factor in terms of their full potential. The current research aimed to characterize rosehip-fruit-extract-loaded liposomes (non-treated and UV-irradiated) in terms of their density, surface tension, viscosity, chemical composition (FTIR and HPLC analyses), and thermal behavior. In the storage stability study, the vesicle size, polydispersity index (PDI), zeta potential, conductivity, and mobility of the liposomes were monitored. FTIR analysis confirmed that the plant compounds were successfully loaded within the carrier, while no chemical reaction between the rosehip fruit extract and phospholipids was detected. The results of the HPLC analysis evidence the high potential for liposomal encapsulation to protect sensitive bioactives in the rosehip fruit extract from the degrading effect of UV irradiation. The size of the rosehip-fruit-extract-encapsulated liposomes increased on the seventh day of storage from 250 nm to 300 nm, while the zeta potential values were between -21 mV and -30 mV in the same period and further stabilized over 60 days of monitoring. In Vitro release studies in water and simulated gastrointestinal fluids showed that the presence of enzymes and bile salts (in intestinal fluid) enhanced the rosehip-polyphenol permeability from liposomes (70.3% after 6 h) compared with their release in water after 24 h and in gastric fluid after 4 h (38.9% and 41.4%, respectively). The obtained results indicate that the proliposome method was an effective method for rosehip fruit extract liposomal encapsulation and for the delivery of these plant-derived bioactives in foods.

Fluorescence of Intrinsic Milk Chromophores as a Novel Verification Method of UV-C Treatment of Milk

The European Food Safety Authority (EFSA) has approved the use of a 1045 J/L UV-C dose as an adjunct to pasteurization to increase the shelf life and vitamin D3 content of milk. However, there are no verification methods analogous to the alkaline phosphatase test for pasteurized milk to ensure that the desired UV-C dose has been correctly applied. The aim is to develop a real-time in-line detector based on fluorescence spectroscopy. In this study, 22 different UV-C doses (ranging from 0 to 2000 J/L) were applied to milk to assess the impact of photooxidation on intrinsic photosensitive chromophores. Fluorescence spectroscopy (90°-angle) was employed as the method of analysis for monitoring the changes in the fluorescence spectra of chromophores in milk without sample pretreatment. Three important chromophore areas (CAs) were identified: CA 1 (riboflavin), CA 3 (vitamin A and dityrosine) and CA 4 (tryptophan), with statistically significant changes at around 1045 J/L and 1500 J/L. The findings of our preliminary study support our hypothesis that the fluorescence of intrinsic chromophores can be used as verification of the applied UV-C dose.

Impact of high-pressure processing on the bioactive compounds of milk - A comprehensive review

High-pressure processing (HPP) is a promising alternative to thermal pasteurization. Recent studies highlighted the effectivity of HPP (400-600 MPa and exposure times of 1-5 min) in reducing pathogenic microflora for up to 5 logs. Analysis of modern scientific sources has shown that pressure affects the main components of milk including fat globules, lactose, casein micelles. The behavior of whey proteins under HPP is very important for milk and dairy products. HPP can cause significant changes in the quaternary (> 150 MPa) and tertiary (> 200 MPa) protein structures. At pressures > 400 MPa, they dissolve in the following order: αs2-casein, αs1-casein, k-casein, and β-casein. A similar trend is observed in the processing of whey proteins. HPP can affect the rate of milk fat adhering as cream with increased results at 100-250 MPa with time dependency while decreasing up to 70% at 400-600 MPa. Some studies indicated the lactose influencing casein on HP, with 10% lactose addition in case in suspension before exposing it to 400 MPa for 40 min prevents the formation of large casein micelles. Number of researches has shown that moderate pressures (up to 400 MPa) and mild heating can activate or stabilize milk enzymes. Pressures of 350-400 MPa for 100 min can boost the activity of milk enzymes by up to 140%. This comprehensive and critical review will benefit scientific researchers and industrial experts in the field of HPP treatment of milk and its effect on milk components.

Graphical abstract

Non-thermal technologies for broiler litter processing: Microbial safety, chemical composition, nutritional value, and fermentation parameters in vitro

BACKGROUND

Annually, a massive amount of broiler litter (BL) is produced in the world, which causes soil and surface water pollution due to its high nitrogen content and microbial count. While ruminants can use this non-protein nitrogen (NPN) source for microbial protein synthesis. This issue becomes more critical when protein sources are unavailable or very expensive. One of the sources of NPN is BL which is produced at a considerable amount in the world yearly.

OBJECTIVES

This aim of this research was to conduct a survey of non-thermal technologies such as electrocoagulation (EC), ultraviolet (UV) radiation, and ultrasound (US) waves on the microbial safety and nutritional value of BL samples as a protein source in ruminant diets.

MATERIALS AND METHODS

The methodology of this study was based on the use of an EC device with 24 V for 60 min, UV-C light radiation (249 nm) for 1 and 10 min, and US waves with a frequency of 28 kHz for 5, 10 and 15 min to process BL samples compared with shade-dried samples. Chemical composition and nutritional values of processed samples were determined by gas production technique and measurement of fermentation parameters in vitro.

RESULTS

Based on the results, microbial safety increased in the samples processed with the US (15 min). The EC method had the best performance in reducing the number of fungi and mould. However, none of the methods could remove total bacteria and fungi. Digestibility of BL was similar in shade-dried, EC, and US (10 min) treatments. In general, the use of EC and US15 without having adverse effects on gas production caused a decrease in the concentration of ammonia nitrogen. In contrast, it caused a decrease in neutral detergent fibre (NDF) in the investigated substrate.

CONCLUSIONS

In general, it can be concluded that the use of US5 and EC methods without having a negative effect on the parameters of gas production and fermentation in vitro, while reducing NDF, causes a significant reduction in the microbial load, pathogens, yeast, and mould. Therefore, it is suggested to use these two methods to improve feed digestibility for other protein and feed sources.

Health Benefits of High Voltage Electrostatic Field Processing of Fruits and Vegetables

High voltage electrostatic field processing (HVEF) is a food preservation procedure frequently used to produce healthy minimally processed fruits and vegetables (F&V) as it reduces the growth of microorganisms and activates or inhibits various enzymes, thus retarding their natural ripening while preserving and even enhancing native nutritional quality and sensory characteristics. HVEF is one of the various nonthermal processing technology (NTPT) regarded as abiotic stress that can activate the antioxidant system of F&V and can also inhibith spoilage enzymes as, polyphenol oxidase (PPO), lipoxygenase (LOX), pectin methylesterase (PME), polygalacturonase (PG), cellulase (Cel), β-xylosidase, xyloglucan and endotransglycosylase/hydrolase, bringing positive effect on hardness, firmness, colour attributes, electric conductivity, antioxidant compounds, microstructure and decreasing electrolyte leakage (EL), malondialdehyde (MDA) contents and browning degree. This technique can also increase the contents of fructose, glucose, and sucrose and decrease the production of CO2 and H2O2. Additionally, it has been reported that HVEF could be used with other treatments, such as modified atmosphere packaging (MAP) and acidic electrolyzed water (AEW) treatment, to enhance its effects. Future works should deepen on elucidating the activation of the antioxidant systems by applying HVEF of critical enzymes related to the synthesis pathways of phenolic compounds (PC) and carotenoids (Car). Holistic approaches to the effects of HVEF on metabolism based on systems biology also need to be studied by considering the overall biochemical, physical, and process engineering related aspects of this technique.

Effect of non-thermal ultraviolet and ultrasound technologies on disinfection of meat preparation equipment in catering industry

In recent years, ultraviolet and ultrasound treatments are gaining attraction as promising green decontamination technologies to ensure microbial safety in food industry. Decontamination by ultraviolet light is a physical process defined by the transfer of electromagnetic energy from a light source to an organism's cellular material and depended on the emission of radiation in the ultraviolet region (100-400 nm), specifically the UV-C region (200-280 nm) which has been demonstrated to be germicidal. Ultrasound technology is defined as sound waves with high and low frequency beyond the limit of human hearing and shows a decontamination effect that occurs as a consequence of cavitation at high power (low frequency) in general. In the present study, it was aimed to determine the effectiveness of ultraviolet light (254 nm, 10 min) and high frequency ultrasound techniques (40 kHz, 10 min) in reducing total aerobic mesophilic bacteria, yeast and mold, Esherichia coli/coliform and Salmonella spp. on the equipment surfaces used in the catering facility. For this purpose, the equipment (cutting knife, meat grinder knife, knife sharpener, cut-proof glove) used in the meat preparation department of catering facility were selected for the treatments. According to the results, appreciable reductions were achieved in total aerobic mesophilic bacterial counts of the ultraviolet treated samples (maximum difference 2.61 log cfu/cm2) and the ultrasound treated samples (maximum difference 4.07 log cfu/cm2). After ultraviolet treatment, Salmonella spp. were totally inhibited on the contaminated surfaces. Furthermore, Escherichia coli/coliform was not detected in the samples after both treatments whereas it was detected before the treatments. It has been concluded that the techniques are effective in reducing microbiological load and also ultraviolet treatment is effective on pathogenic microorganisms on food contact surfaces. As a result, the ultraviolet and ultrasound techniques are effective treatments for equipment disinfection in the catering sector and can be used industrially as it gives successful results.

UV-Induced Spectral and Morphological Changes in Bacterial Spores for Inactivation Assessment

The ability to detect and inactivate spore-forming bacteria is of significance within, for example, industrial, healthcare, and defense sectors. Not only are stringent protocols necessary for the inactivation of spores but robust procedures are also required to detect viable spores after an inactivation assay to evaluate the procedure's success. UV radiation is a standard procedure to inactivate spores. However, there is limited understanding regarding its impact on spores' spectral and morphological characteristics. A further insight into these UV-induced changes can significantly improve the design of spore decontamination procedures and verification assays. This work investigates the spectral and morphological changes to Bacillus thuringiensis spores after UV exposure. Using absorbance and fluorescence spectroscopy, we observe an exponential decay in the spectral intensity of amino acids and protein structures, as well as a logistic increase in dimerized DPA with increased UV exposure on bulk spore suspensions. Additionally, using micro-Raman spectroscopy, we observe DPA release and protein degradation with increased UV exposure. More specifically, the protein backbone's 1600-1700 cm-1 amide I band decays slower than other amino acid-based structures. Last, using electron microscopy and light scattering measurements, we observe shriveling of the spore bodies with increased UV radiation, alongside the leaking of core content and disruption of proteinaceous coat and exosporium layers. Overall, this work utilized spectroscopy and electron microscopy techniques to gain new understanding of UV-induced spore inactivation relating to spore degradation and CaDPA release. The study also identified spectroscopic indicators that can be used to determine spore viability after inactivation. These findings have practical applications in the development of new spore decontamination and inactivation validation methods.

Postharvest of fresh white shimeji mushroom subjected to UV-C radiation

This study aimed to evaluate the postharvest characteristics of edible fresh white shimeji mushrooms under different UV-C radiation doses. The experimental design used was fully randomized, in a 5 × 8 factorial scheme (UV-C radiation dose: 0 (control), 1, 2, 3, and 4 kJ m-2 x day of analysis), with 3 replications of 70 ± 1 g mushrooms each. After exposure to different doses, they were stored at 2 ± 0.5 °C and 60 ± 3.8 % RH. Data were subjected to permutational multivariate analysis (PERMANOVA) (p ≤ 0.05). There was no significance for interaction, nor the factor day, only for the UV-C radiation doses factor. Regarding PCA, among the doses applied, the dose of 2 kJ m-2 was effective in maintaining the quality of mushrooms with greater lightness, greater whiteness index, a greater amount of total extractable polyphenols, and total antioxidant activity. In conclusion, the dose of 2 kJ m-2 was effective in maintaining the postharvest quality of white shimeji mushrooms.

Principles and Applications of Non-Thermal Technologies for Meat Decontamination

Meat contains high-value protein compounds that might degrade as a result of oxidation and microbial contamination. Additionally, various pathogenic and spoilage microorganisms can grow in meat. Moreover, contamination with pathogenic microorganisms above the infectious dose has caused foodborne illness outbreaks. To decrease the microbial population, traditional meat preservation methods such as thermal treatment and chemical disinfectants are used, but it may have limitations for the maintenance of meat quality or the consumers acceptance. Thus, non-thermal technologies (e.g., high-pressure processing, pulsed electric field, non-thermal plasma, pulsed light, supercritical carbon dioxide technology, ozone, irradiation, ultraviolet light, and ultrasound) have emerged to improve the shelf life and meat safety. Non-thermal technologies are becoming increasingly important because of their advantages in maintaining low temperature, meat nutrition, and short processing time. Especially, pulsed light and pulsed electric field treatment induce few sensory and physiological changes in high fat and protein meat products, making them suitable for the application. Many research results showed that these non-thermal technologies may keep meat fresh and maintain heat-sensitive elements in meat products.

Advancements in nonthermal physical field technologies for prefabricated aquatic food: A comprehensive review

Aquatic foods are nutritious, enjoyable, and highly favored by consumers. In recent years, young consumers have shown a preference for prefabricated food due to its convenience, nutritional value, safety, and increasing market share. However, aquatic foods are prone to microbial spoilage due to their high moisture content, protein content, and unsaturated fatty acids. Furthermore, traditional processing methods of aquatic foods can lead to issues such as protein denaturation, lipid peroxidation, and other food safety and nutritional health problems. Therefore, there is a growing interest in exploring new technologies that can achieve a balance between antimicrobial efficiency and food quality. This review examines the mechanisms of cold plasma, high-pressure processing, photodynamic inactivation, pulsed electric field treatment, and ultraviolet irradiation. It also summarizes the research progress in nonthermal physical field technologies and their application combined with other technologies in prefabricated aquatic food. Additionally, the review discusses the current trends and developments in the field of prefabricated aquatic foods. The aim of this paper is to provide a theoretical basis for the development of new technologies and their implementation in the industrial production of prefabricated aquatic food.

Non-thermal technologies for the conservation of açai pulp and derived products: A comprehensive review

Açai (Euterpe oleracea) is one of the main sustainable extractive crops in the Amazon region, widely consumed by the local population and a significant export product. This review presents the current knowledge regarding nonthermal technologies employed in açai processing. This review aims to discuss and compare the main results attained by the application of HPP, ultrasound, ozone, UV light, cold plasma, and pulsed electric field on microbial inactivation, enzymatic inhibition, and the content of anthocyanin and other bioactive compounds after açai pulp processing. The discussion compares these technologies with pasteurization, the current main technology applied to açai sanitization. This review shows that there are still many gaps to be filled concerning açai processing in thermal and non-thermal technologies. Data analysis allowed the conclusion that pasteurization and HPP are, up to now, the only technologies that enable a 5-log CFU reduction of yeasts, molds, and some bacteria in açai. However, no study has reported the inactivation of Trypanosoma cruzi, which is the major gap found in current knowledge. Other technologies, such as pulsed electric field, cold plasma, and ultrasound, require further development and process intensification studies to be as successful as HPP and pasteurization.

Comparison of the efficacy of physical and chemical strategies for the inactivation of biofilm cells of foodborne pathogens

Biofilm formation is a strategy in which microorganisms generate a matrix of extracellular polymeric substances to increase survival under harsh conditions. The efficacy of sanitization processes is lowered when biofilms form, in particular on industrial devices. While various traditional and emerging technologies have been explored for the eradication of biofilms, cell resistance under a range of environmental conditions renders evaluation of the efficacy of control challenging. This review aimed to: (1) classify biofilm control measures into chemical, physical, and combination methods, (2) discuss mechanisms underlying inactivation by each method, and (3) summarize the reduction of biofilm cells after each treatment. The review is expected to be useful for future experimental studies and help to guide the establishment of biofilm control strategies in the food industry.

Recent developments in applications of physical fields for microbial decontamination and enhancing nutritional properties of germinated edible seeds and sprouts: a review

Germinated edible seeds and sprouts have attracted consumers because of their nutritional values and health benefits. To ensure the microbial safety of the seed and sprout, emerging processing methods involving physical fields (PFs), having the characteristics of high efficiency and environmental safety, are increasingly proposed as effective decontamination processing technologies. This review summarizes recent progress on the application of PFs to germinating edible seeds, including their impact on microbial decontamination and nutritional quality and the associated influencing mechanisms in germination. The effectiveness, application scope, and limitation of the various physical techniques, including ultrasound, microwave, radio frequency, infrared heating, irradiation, pulsed light, plasma, and high-pressure processing, are symmetrically reviewed. Good application potential for improving seed germination and sprout growth is also described for promoting the accumulation of bioactive compounds in sprouts, and subsequently enhancing the antioxidant capacity under favorable PFs processing conditions. Moreover, the challenges and future directions of PFs in the application to germinated edible seeds are finally proposed. This review also attempts to provide an in-depth understanding of the effects of PFs on microbial safety and changes in nutritional properties of germinating edible seeds and a theoretical reference for the future development of PFs in processing safe sprouted seeds.

Current physical techniques for the degradation of aflatoxins in food and feed: Safety evaluation methods, degradation mechanisms and products

Aflatoxins are the most toxic natural mycotoxins discovered so far, posing a serious menace to the food safety and trading economy of the world, especially developing countries. How to effectively detoxify has persistently occupied a place on the list of "global hot-point" concerns. Among the developed detoxification methods, physical methods, as the authoritative techniques for aflatoxins degradation, could rapidly induce irreversible denaturation of aflatoxins. This review presents a brief overview of aflatoxins detection and degradation product structure identification methods. Four main safety evaluation methods for aflatoxins and degradation product toxicity assessment are highlighted combined with an update on research of aflatoxins decontamination in the last decade. Furthermore, the latest applications, degradation mechanisms and products of physical aflatoxin decontamination techniques including microwave heating, irradiation, pulsed light, cold plasma and ultrasound are discussed in detail. Regulatory issues related to "detoxification" are also explained. Finally, we put forward the challenges and future work in studying aflatoxin degradation based on the existing research. The purpose of supplying this information is to help researchers have a deeper understanding on the degradation of aflatoxins, break through the existing bottleneck, and further improve and innovate the detoxification methods of aflatoxins.

UV-C Light: A Promising Preservation Technology for Vegetable-Based Nonsolid Food Products

A variety of bioactive substances present in fruit- and vegetable-processed products have health-promoting properties. The consumption of nutrient-rich plant-based products is essential to address undernutrition and micronutrient deficiencies. Preservation is paramount in manufacturing plant-based nonsolid foods such as juices, purees, and sauces. Thermal processing has been widely used to preserve fruit- and vegetable-based products by reducing enzymatic and microbial activities, thereby ensuring safety and prolonged shelf life. However, the nutritional value of products is compromised due to the deleterious effects of thermal treatments on essential nutrients and bioactive compounds. To prevent the loss of nutrients associated with thermal treatment, alternative technologies are being researched extensively. In studies conducted on nonsolid food, UV-C treatment has been proven to preserve quality and minimize nutrient degradation. This review compiles information on the use of UV-C technology in preserving the nutritional attributes of nonsolid foods derived from fruit and vegetables. The legislation, market potential, consumer acceptance, and limitations of UV-C are reviewed.

Rosehip Extract-Loaded Liposomes for Potential Skin Application: Physicochemical Properties of Non- and UV-Irradiated Liposomes

In the present study, rosehip (Rosa canina L.) extract was successfully encapsulated in phospholipid liposomes using a single-step procedure named the proliposome method. Part of the obtained liposomes was subjected to UV irradiation and non-treated (native) and UV-irradiated liposomes were further characterized in terms of encapsulation efficiency, chemical composition (HPLC analysis), antioxidant capacity, particle size, PDI, zeta potential, conductivity, mobility, and antioxidant capacity. Raman spectroscopy as well as DSC analysis were applied to evaluate the influence of UV irradiation on the physicochemical properties of liposomes. The encapsulation efficiency of extract-loaded liposomes was higher than 90%; the average size was 251.5 nm; the zeta potential was -22.4 mV; and the conductivity was found to be 0.007 mS/cm. UV irradiation did not cause a change in the mentioned parameters. In addition, irradiation did not affect the antioxidant potential of the liposome-extract system. Raman spectroscopy indicated that the extract was completely covered by the lipid membrane during liposome entrapment, and the peroxidation process was minimized by the presence of rosehip extract in liposomes. These results may guide the potential application of rosehip extract-loaded liposomes in the food, pharmaceutical, or cosmetic industries, particularly when liposomal sterilization is needed.

Ultraviolet C irradiation: A promising approach for the disinfection of public spaces?

Ultraviolet irradiation C (UVC) has emerged as an effective strategy for microbial control in indoor public spaces. UVC is commonly applied for air, surface, and water disinfection. Unlike common 254 nm UVC, far-UVC at 222 nm is considered non-harmful to human health, being safe for occupied spaces, and still effective for disinfection purposes. Therefore, and allied to the urgency to mitigate the current pandemic of SARS-CoV-2, an increase in UVC-based technology devices appeared in the market with levels of pathogens reduction higher than 99.9 %. This environmentally friendly technology has the potential to overcome many of the limitations of traditional chemical-based disinfection approaches. The novel UVC-based devices were thought to be used in public indoor spaces such as hospitals, schools, and public transport to minimize the risk of pathogens contamination and propagation, saving costs by reducing manual cleaning and equipment maintenance provided by manpower. However, a lack of information about UVC-based parameters and protocols for disinfection, and controversies regarding health and environmental risks still exist. In this review, fundamentals on UVC disinfection are presented. Furthermore, a deep analysis of UVC-based technologies available in the market for the disinfection of public spaces is addressed, as well as their advantages and limitations. This comprehensive analysis provides valuable inputs and strategies for the development of effective, reliable, and safe UVC disinfection systems.

Investigation of differences in susceptibility of Campylobacter jejuni strains to UV light-emitting diode (UV-LED) technology

Campylobacter jejuni remains a high priority in public health worldwide. Ultraviolet light emitting-diode technology (UV-LED) is currently being explored to reduce Campylobacter levels in foods. However, challenges such as differences in species and strain susceptibilities, effects of repeated UV-treatments on the bacterial genome and the potential to promote antimicrobial cross-protection or induce biofilm formation have arisen. We investigated the susceptibility of eight C. jejuni clinical and farm isolates to UV-LED exposure. UV light at 280 nm induced different inactivation kinetics among strains, of which three showed reductions greater than 1.62 log CFU/mL, while one strain was particularly resistant to UV light with a maximum reduction of 0.39 log CFU/mL. However, inactivation was reduced by 0.46-1.03 log CFU/mL in these three strains and increased to 1.20 log CFU/mL in the resistant isolate after two repeated-UV cycles. Genomic changes related to UV light exposure were analysed using WGS. C. jejuni strains with altered phenotypic responses following UV exposure were also found to have changes in biofilm formation and susceptibility to ethanol and surface cleaners.

Impact of Physicochemical Modifications in Casein Promoted by UV-C on the Peptide Profile of Gastric Digestion and the Transepithelial Transport of Peptides

Caseins are the main proteins in milk, and their structure and spatial conformation are responsible for their slow digestion rate. The release of bioactive and β-casomorphin peptides from casein digestion may induce allergic responses during consumption. Spectroscopic techniques were used to observe the structural changes in casein conformation induced by Ultraviolet light irradiation (UV-C). Raman spectroscopy results showed more pronounced peaks at 618 and 640 cm^-1 for phenylalanine and tyrosine moieties of the photolyzed micellar casein, respectively, suggesting changes in the micelle structure. The decrease in the intensity of Raman signals for tryptophan and tyrosine corroborates to the UV-C-induced modifications of the micelle structure. Particle size distribution showed a decrease in the average micelle size after 15 min of UV-C exposure, while low-temperature, long-time (LTLT) pasteurization led to the formation of large aggregates, as observed by atomic force microscopy. UV-C did not impact the formation or transport of peptides, as observed by using the Caco-2 cell as a model for peptide absorption. However, the absence of the opioid peptide SRYPSY from κ-casein and only 20% of the concentration of opioid peptide RYLGY were noted. This work demonstrated that UV-C can be utilized to induce the physicochemical modification of dairy products, promoting a higher digestion rate and reducing allergenicity.

Biointerface mineralization generates ultraresistant gut microbes as oral biotherapeutics

Despite the fact that oral microecologics are effective in modulating the gut microbiome, they always suffer from multiple insults during the journey from manufacture to arrival at the intestine. Inspired by the protective mechanism of mineralization, we describe a cytocompatible approach of biointerface mineralization that can generate an ultraresistant and self-removable coating on bacterial surface to solve these challenges. Mineral coating endows bacteria with robust resistances against manufacture-associated oxygen exposure, ultraviolet irradiation, and 75% ethanol. Following oral ingestion, the coating is able to actively neutralize gastric acid and release encapsulated bacteria through spontaneous yet rapid double-decomposition reaction. In addition to acid neutralization, the generated calcium ions can trigger micellar aggregation of bile acid, enabling dual exemptions from the insults of gastric acid and bile acid to achieve uncompromised bacterial viability. Further supported by the therapeutic efficacy of coated bacteria toward colitis mice, biointerface mineralization provides a versatile platform for developing next-generation living oral biotherapeutics.

Effect of combining UV-C irradiation and vacuum sealing on the shelf life of fresh strawberries and tomatoes

This research presents the effect of combining UV-C irradiation and vacuum sealing on the shelf life of strawberries and quartered tomatoes and compares it with the effect of the sole use of UV-C irradiation or vacuum sealing. A constant UV-C dose of 360 J/m² was used for the samples' irradiation, and all the vacuum-sealed samples were stored at a reduced pressure of 40 kPa. Organoleptic analysis, microbial population quantification of yeast and mold, Pseudomonas sp., weight loss, and pH measurements were obtained to identify the spoilage occurrence, monitor the samples' quality, and quantify the shelf life. Sensory evaluation was conducted by 12 consumer panelists to evaluate the aroma, taste, color, texture, and the overall acceptance of the samples. The results revealed that the combination of UV-C irradiation and vacuum sealing prolongs the shelf life of perishables more than the sole use of UV-C irradiation or vacuum sealing. The achieved shelf-life increase using this combination was 124.41% and 54.41% for strawberries and quartered tomatoes, respectively, while acceptable sensory characteristics were maintained throughout the storage period. Hence, this food preservation method can be further improved and integrated in the daily life of modern consumers and the operations of fresh produce retailers, as it could effectively reduce the spoilage rates of fresh produce and help achieve the UN SDG 12.3, which aims to reduce food loss and waste by 50% by 2030 at the consumer and retail levels. PRACTICAL APPLICATION: The system can be further developed and introduced to the market as a kitchen appliance for households or as a predistribution step for fresh produce distribution centers. The shelf-life extension capability of this system, which does not involve any use of chemical substances, would make it an attractive solution for households and food retailers.

Understanding the interaction of nucleotides with UVC light: an insight from quantum chemical calculation-based findings

Short-wave ultraviolet (also called UVC) irradiation is a well-adopted method of viral inactivation due to its ability to damage genetic material. A fundamental problem with the UVC inactivation method is that its mechanism of action on viruses is still unknown at the molecular level. To address this problem, herein we investigate the response mechanism of genome materials to UVC light by means of quantum chemical calculations. The spectral properties of four nucleotides, namely, adenine, cytosine, guanine, and uracil, are mainly focused on. Meanwhile, the transition state and reaction rate constant of uracil molecules are also considered to demonstrate the difficulty level of adjacent nucleotide reaction without and with UVC irradiation. The results show that the peak wavelengths are 248.7 nm, 226.1 nm (252.7 nm), 248.3 nm, and 205.8 nm (249.2 nm) for adenine, cytosine, guanine, and uracil nucleotides, respectively. Besides, the reaction rate constants of uracil molecules are 6.419 × 10^-49 s^-1 M^-1 and 5.436 × 10¹¹ s^-1 M^-1 for the ground state and excited state, respectively. Their corresponding half-life values are 1.56 × 10⁴⁸ s and 1.84 × 10^-12 s. This directly suggests that the molecular reaction between nucleotides is a photochemical process and the reaction without UVC irradiation almost cannot occur.

Quercetin mediated antimicrobial photodynamic treatment using blue light on Escherichia coli O157:H7 and Listeria monocytogenes

Interest in using an antimicrobial photodynamic treatment (aPDT) for the microbial decontamination of food has been growing. In this study, quercetin, a substance found ubiquitously in plants, was used as a novel exogenous photosensitizer with 405 nm blue light (BL) for the aPDT on foodborne pathogens, and the inactivation mechanism was elucidated. The inactivation of Escherichia coli O157:H7 and Listeria monocytogenes in PBS solution by the quercetin and BL combination treatment reached a log reduction of 6.2 and more than 7.55 at 80 J/cm² (68 min 21 s), respectively. When EDTA was added to investigate the reason for different resistance between two bacteria, the effect of aPDT was enhanced against E. coli O157:H7 but not L. monocytogenes. This result indicated that the lipopolysaccharide of Gram-negative bacteria operated as a protective barrier. It was experimentally demonstrated that quercetin generated the superoxide anion and hydrogen peroxide as the reactive oxygen species that oxidize and inactivate cell components. The damage to the bacterial cell membrane by aPDT was evaluated by propidium iodide, where the membrane integrity significantly (P < 0.05) decreased from 40 J/cm² compared to control. In addition, DNA integrity of bacteria was significantly (P < 0.05) more decreased after aPDT than BL treatment. The inactivation results could be applied in liquid food industries for decontamination of foodborne pathogens, and the mechanisms data was potentially utilized for further studies about aPDT using quercetin.

Liposomal Bilayer as a Carrier of Rosa canina L. Seed Oil: Physicochemical Characterization, Stability, and Biological Potential

Rosa canina L. seeds are rich in bioactive components that can add value to the various formulations. The focus of the study was the development of liposomes for R. canina oil to protect its sensitive compounds and prolong their shelf-life. Oil-loaded liposomes were characterized via the determination of the particle size, polydispersity index (PDI), zeta potential, conductivity, mobility, density, surface tension, viscosity, and stability. Raman and FT-IR spectroscopy were employed to investigate the chemical composition of the non-treated and UV-treated samples, and the presence of different interactions. Antioxidant and antimicrobial activities were examined as well. The liposome size was 970.4 ± 37.4 nm, the PDI 0.438 ± 0.038, the zeta potential -32.9 ± 0.8 mV, the conductivity 0.068 ± 0.002 mS/cm, the mobility -2.58 ± 0.06 µmcm/Vs, the density 0.974 ± 0.004 g/cm³, the surface tension 17.2 ± 1.4 mN/m, and the viscosity 13.5 ± 0.2 mPa•s. The Raman and FT-IR spectra showed the presence of lipids, fatty acids, polyphenols, and carotenoids. It was approved that the oil compounds were distributed inside the phospholipid bilayer and were combined with the membrane interface of the bilayer. The UV irradiation did not cause any chemical changes. However, neither the pure oil nor the oil-loaded liposomes showed any antimicrobial potential, while the antioxidant capacity of the oil-loaded liposomes was significantly low. The sizes of the liposomes did not change significantly during 60 days of storage. Due to the proven stability of the oil-loaded liposomes, as well as the liposome's ability to protect the sensitive oil compounds, their potential application in the pharmaceutical and cosmetic formulations could be investigated with a focus on the skin regeneration effects.

Recent advances and potentiality of postbiotics in the food industry: Composition, inactivation methods, current applications in metabolic syndrome, and future trends

Postbiotics are defined as "preparation of inanimate microorganisms and/or their components that confers a health benefit on the host". Postbiotics have unique advantages over probiotics, such as stability, safety, and wide application. Although postbiotics are research hotspots, the research on them is still very limited. This review provides comprehensive information on the scope of postbiotics, the preparation methods of inanimate microorganisms, and the application and mechanisms of postbiotics in metabolic syndrome (MetS). Furthermore, the application trends of postbiotics in the food industry are reviewed. It was found that postbiotics mainly include inactivated microorganisms, microbial lysates, cell components, and metabolites. Thermal treatments are the main methods to prepare inanimate microorganisms as postbiotics, while non-thermal treatments, such as ionizing radiation, ultraviolet light, ultrasound, and supercritical CO2, show great potential in postbiotic preparation. Postbiotics could ameliorate MetS through multiple pathways including the modulation of gut microbiota, the enhancement of intestinal barrier, the regulation of inflammation and immunity, and the modulation of hormone homeostasis. Additionally, postbiotics have great potential in the food industry as functional food supplements, food quality improvers, and food preservatives. In addition, the SWOT analyses showed that the development of postbiotics in the food industry exists both opportunities and challenges.

Alteration of the allergenicity of cow's milk proteins using different food processing modifications

Milk is an essential source of protein for infants and young children. At the same time, cow's milk is also one of the most common allergenic foods causing food allergies in children. Recently, cow's milk allergy (CMA) has become a common public health issue worldwide. Modern food processing technologies have been developed to reduce the allergenicity of milk proteins and improve the quality of life of patients with CMA. In this review, we summarize the main allergens in cow's milk, and introduce the recent findings on CMA responses. Moreover, the reduced effects and underlying mechanisms of different food processing techniques (such as heating, high pressure, γ-ray irradiation, ultrasound irradiation, hydrolysis, glycosylation, etc.) on the allergenicity of cow's milk proteins, and the application of processed cow's milk in clinical studies, are discussed. In addition, we describe the changes of nutritional value in cow's milk treated by different food processing technologies. This review provides an in-depth understanding of the allergenicity reduction of cow's milk proteins by various food processing techniques.

Impact of irradiation on physico-chemical and nutritional properties of fruits and vegetables: A mini review

Background

Fruits and vegetables are healthy because they contain good nutrients and secondary metabolites that keep the body healthy and disease-free. Post-harvest losses of fresh fruits and vegetables limit access and availability as a result of foodborne infections and poor storage technologies. The selection of fruits and vegetables depend on the starting microbial load, the size of fruits and vegetables, and the type of infrastructure.

Scope and approach

Despite the positive impacts of conventional thermal (roasting, boiling, blanching) and some non-thermal processing techniques such as High Pressure Processing (HPP), Pulse Electric Field (PEF), Cold Plasma Technology (CPT) on shelf-life extension, their use is commonly associated with a number of negative consequences on product quality such as cold plasma treatment increases the acidity and rate of lipid oxidation and further decrease the colour intensity and firmness of products. Similarly, in high pressure processing and pulse electric field there is no spore inactivation and they further limit their application to semi-moist and liquid foods. On that account, food irradiation, a non-thermal technique, is currently being used for post-harvest preservation, which could be very useful in retaining the keeping quality of various fresh and dehydrated products without negatively affecting their versatility and physico-chemical, nutritional and sensory properties.

Conclusion

Existing studies have communicated the effective influence of irradiation technology on nutritional, sensory, and physico-chemical properties of multiple fruits and vegetables accompanying consequential deduction in microbial load throughout the storage period. Food irradiation can be recognized as a prevalent, safe and promising technology however, still is not fully exploited on a magnified scale. The consumer acceptance of processed products has always been a significant challenge for innovative food processing technologies such as food irradiation. Therefore, owing to current review, additional scientific evidences and efforts are still demanded for increasing its technological request.

Evaluation of the impact of UV radiation on rheological and textural properties of food

Demand for healthy, safe, and high-quality foods and disadvantages of thermal processing methods such as quality losses supported the improvement of the novel, affordable, and quick nonthermal food preservation techniques such as UV light. UV-C light (200-280 nm) radiation is an emerging technology for the disinfection of pathogen microorganisms, increasing the shelf life of foods, and used for pasteurization, surface sterilization, cleaning of equipment and water, and so on. Sensory perceptions of foods are effective on the consumer choice, acceptability, and consumption of foods. Rheology term, which also includes texture and mouthfeel, is primarily important for sensory perception, processing of foods, and shelf stability. Therefore, the determination of the effect of different processing methods on the textural and rheological properties of the food products is important. Rheological and textural changes generally occur in the surface of UV-C-irradiated samples due to the low penetration of UV-C light. The UV light treatment may cause internal disruption of cell membranes, which in turn cause loss of turgidity, weaken the cell walls, and contraction of tissues, which are related to the changes in the textural and rheological properties of foods. The present review focuses on the effect of UV-C radiation on the rheology and textural properties of food products.

Current progress of emerging technologies in human and animals' milk processing: Retention of immune-active components and microbial safety

Human milk and commercial dairy products play a vital role in humans, as they can provide almost all essential nutrients and immune-active components for the development of children. However, how to retain more native immune-active components of milk during processing remains a big question for the dairy industry. Nonthermal technologies for milk processing are gaining increasing interest in both academic and industrial fields, as it is known that thermal processing may negatively affect the quality of milk products. Thermosensitive components, such as lactoferrin, immunoglobulins (Igs), growth factors, and hormones, are highly important for the healthy development of newborns. In addition to product quality, thermal processing also causes environmental problems, such as high energy consumption and greenhouse gas (GHG) emissions. This review summarizes the recent advances of UV-C, ultrasonication (US), high-pressure processing (HPP), and other emerging technologies for milk processing from the perspective of immune-active components retention and microbial safety, focusing on human, bovine, goat, camel, sheep, and donkey milk. Also, the detailed application, including the instrumental design, technical parameters, and obtained results, are discussed. Finally, future prospects and current limitations of nonthermal techniques as applied in milk processing are discussed. This review thereby describes the current state-of-the-art in nonthermal milk processing techniques and will inspire the development of such techniques for in-practice applications in milk processing.

Possibilities of using the continuous type of UV light on the surface of lor (whey) cheese: impacts on mould growth, oxidative stability, sensory and colour attributes during storage

This research paper addresses the hypothesis that the optimum doses of a continuous type of ultraviolet (UV) light applied to the surface of lor (whey) cheese needs to be identified to maximize mould inactivation and shelf life while minimizing quality deterioration. Therefore, the mould inactivation, protein and lipid oxidation products, sensory and colour attributes of lor cheese subjected to different doses of UV light (1.617, 4.018, and 36.832 kJ/m2) in a continuous type of UV system were evaluated. UV treated samples presented mould counts lower than those of untreated ones. UV treatment at more than 4.018 kJ/m2 allowed around 0.7-2.7 log reductions on mould growth during storage. The increase in UV light dose caused significant increases in primary and secondary lipid oxidation products. In particular, the highest doses applied to the surface of cheese samples had the highest values of protein carbonyls, as well as lipid oxidation products. Strong positive correlations were recorded between lipid and protein oxidation markers. Exposure to the highest doses of UV light increased foreign flavour perception, probably due to the oxidative reactions. The results indicated that the application of UV light to the lor cheese surface allowed delaying mould growth during storage but extreme doses could induce lipid and protein oxidation reactions, leading to quality deterioration.

Chemical Nature of Metals and Metal-Based Materials in Inactivation of Viruses

In response to the enormous threat to human survival and development caused by the large number of viruses, it is necessary to strengthen the defense against and elimination of viruses. Metallic materials have been used against viruses for thousands of years due to their broad-spectrum antiviral properties, wide sources and excellent physicochemical properties; in particular, metal nanoparticles have advanced biomedical research. However, researchers in different fields hold dissimilar views on the antiviral mechanisms, which has slowed down the antiviral application of metal nanoparticles. As such, this review begins with an exhaustive compilation of previously published work on the antiviral capacity of metal nanoparticles and other materials. Afterwards, the discussion is centered on the antiviral mechanisms of metal nanoparticles at the biological and physicochemical levels. Emphasis is placed on the fact that the strong reducibility of metal nanoparticles may be the main reason for their efficient inactivation of viruses. We hope that this review will benefit the promotion of metal nanoparticles in the antiviral field and expedite the construction of a barrier between humans and viruses.

The Effect of UV-C Irradiation on the Mechanical and Physiological Properties of Potato Tuber and Different Products

Amongst the surface treatment technologies to emerge in the last few decades, UV-C radiation surface treatment is widely used in food process industries for the purpose of shelf life elongation, bacterial inactivation, and stimulation. However, the short wave application is highly dose-dependent and induces different properties of the product during exposure. Mechanical properties of the agricultural products and their derivatives represent the key indicator of acceptability by the end-user. This paper surveys the recent findings of the influence of UV-C on the stress response and physiological change concerning the mechanical and textural properties of miscellaneous agricultural products with a specific focus on a potato tuber. This paper also reviewed the hormetic effect of UV-C triggered at a different classification of doses studied so far on the amount of phenolic content, antioxidants, and other chemicals responsible for the stimulation process. The combined technologies with UV-C for product quality improvement are also highlighted. The review work draws the current challenges as well as future perspectives. Moreover, a way forward in the key areas of improvement of UV-C treatment technologies is suggested that can induce a favorable stress, enabling the product to achieve self-defense mechanisms against wound, impact, and mechanical damage.

Non-thermal Processing Technologies for Dairy Products: Their Effect on Safety and Quality Characteristics

Thermal treatment has always been the processing method of choice for food treatment in order to make it safe for consumption and to extend its shelf life. Over the past years non-thermal processing technologies are gaining momentum and they have been utilized especially as technological advancements have made upscaling and continuous treatment possible. Additionally, non-thermal treatments are usually environmentally friendly and energy-efficient, hence sustainable. On the other hand, challenges exist; initial cost of some non-thermal processes is high, the microbial inactivation needs to be continuously assessed and verified, application to both to solid and liquid foods is not always available, some organoleptic characteristics might be affected. The combination of thermal and non-thermal processing methods that will produce safe foods with minimal effect on nutrients and quality characteristics, while improving the environmental/energy fingerprint might be more plausible.

Pequi (Caryocar brasiliense) Waste Extract as a Synergistic Agent in the Microbial and Physicochemical Preservation of Low-Sodium Raw Goat Cheese

The growth of spoilage and pathogenic bacteria during storage represents significant losses in marketing raw milk cheeses. Thus, reducing NaCl in these products is challenging, as sodium has a critical antimicrobial role. Despite advances in non-thermal technologies, the short shelf life still limits the availability of raw goat cheese. Thus, combined preservation methods can be promising because their synergies can extend shelf life more effectively. In this context, Principal Component Analysis (PCA) was applied to variables to investigate the effect of pequi waste extract (PWE), a native Brazilian fruit, combined with UV-C radiation (CEU) and vacuum packaging (CEV) on the preservation of low-sodium raw goat cheese. CEV samples had lower loadings for Staphylococcus subsp. and Enterobacteriaceae than other treatments in PC2, having a count's reduction up to 3-fold (P < 0.05) compared to vacuum alone. In contrast, CEU showed an increase of up to 1.2-fold on staphylococcal count compared to UV-C alone. Still, the addition of PWE to UV-C-treated cheeses resulted in 8.5% protein loss. Furthermore, PWE, especially in CEV, delayed post-acidification during storage. It made CEV up to 4.5 and 1.6-fold more stable for color and texture, respectively than vacuum alone. These data strongly suggest that PWE may be a novel and promising synergistic agent in the microbial and physicochemical preservation of low-sodium raw milk cheese when combined with the vacuum.

Postharvest Ultraviolet Radiation in Fruit and Vegetables: Applications and Factors Modulating Its Efficacy on Bioactive Compounds and Microbial Growth

Ultraviolet (UV) radiation has been considered a deleterious agent that living organisms must avoid. However, many of the acclimation changes elicited by UV induce a wide range of positive effects in plant physiology through the elicitation of secondary antioxidant metabolites and natural defenses. Therefore, this fact has changed the original UV conception as a germicide and potentially damaging agent, leading to the concept that it is worthy of application in harvested commodities to take advantage of its beneficial responses. Four decades have already passed since postharvest UV radiation applications began to be studied. During this time, UV treatments have been successfully evaluated for different purposes, including the selection of raw materials, the control of postharvest diseases and human pathogens, the elicitation of nutraceutical compounds, the modulation of ripening and senescence, and the induction of cross-stress tolerance. Besides the microbicide use of UV radiation, the effect that has received most attention is the elicitation of bioactive compounds as a defense mechanism. UV treatments have been shown to induce the accumulation of phytochemicals, including ascorbic acid, carotenoids, glucosinolates, and, more frequently, phenolic compounds. The nature and extent of this elicitation have been reported to depend on several factors, including the product type, maturity, cultivar, UV spectral region, dose, intensity, and radiation exposure pattern. Even though in recent years we have greatly increased our understanding of UV technology, some major issues still need to be addressed. These include defining the operational conditions to maximize UV radiation efficacy, reducing treatment times, and ensuring even radiation exposure, especially under realistic processing conditions. This will make UV treatments move beyond their status as an emerging technology and boost their adoption by industry.

Evaluation of nano-silica, microwave heating, and ultraviolet irradiation effects on zearalenone detoxification in sunflower oils

In the present study, we report three methods of silica nanoparticles (SNPs) as adsorbent, ultraviolet (UV) irradiation, and microwave heating and evaluate their capabilities in reducing and eliminating zearalenone (ZEN). The offered method not only was used for ZEN detoxification, but also greatly enhanced the sensitivity of ZEN measurement. The aim of this study was to evaluate ZEN concentration in sunflower oil samples by high-performance liquid chromatography (HPLC) method. This method was successfully validated for sunflower oil samples while the limit of detection (LOD) method (signal-to-noise ratio of 3:1) was 0.5 μg/l. The acquired removal data with the HPLC method through SNPs were fitted well with Freundlich isotherm, denoting that the multi-layer adsorption took place on the adsorbent. The equilibrium adsorption capacity of ZEN was 61.02 μg/g in an optimum time of 240 min on SNPs. The experimental results were evaluated by the adsorption kinetic model, which specified the adsorption kinetics of ZEN on SNPs, obeying the pseudo-second order model. This model demonstrated that the sorption rate depended on the sorption capacity but not the concentration of the sorbate. Moreover, the method presented to determine ZEN based on the use of SNPs in sunflower oil was accomplished by the adsorption process. Furthermore, the removal efficiencies of ZEN by SNPs, UV irradiation, and microwave heating were compared and obtained to be 92.1, 96.22, and 37.30%, respectively for determined times. These results confirm the removal efficiency of these methods is sensitive enough to ZEN analysis in sunflower oil samples.

Current insights into non-thermal preservation technologies alternative to conventional high-temperature short-time pasteurization of drinking milk

Milk is an important nutritional food source characterized by a perishable nature and conventionally thermally treated to guarantee its safety. In recent years, an increasing focus on competing non-thermal food processing technologies has been driven mainly by consumers' expectations for minimally processed products. Due to the heat sensitivity of milk, much research interest has been addressed to mild non-thermal pasteurization processing to keep safety, 'fresh-like' taste and to maintain the organoleptic qualities of raw milk. This review provides an overview of the current literature on non-thermal treatments as standalone alternative technologies to high-temperature short-time (HTST) pasteurization of drinking milk. Results of lab-scale experimentations suggest the feasibility of most emerging non-thermal processing technologies, including high hydrostatic pressure, pulsed electric field, cold plasma, cavitation and light-based technologies, as alternative to thermal treatment of drinking milk with premium in shelf life duration. Nevertheless, a series of regulatory, technological and economical hurdles hinder the industrial scaling-up for most of these substitutes. To date, only high hydrostatic pressure treatments are applied as alone alternative to HTSH pasteurization for processing of "cold pasteurized" drinking milk. Milk submitted to HTST treatment combined to ultraviolet light is currently accepted in EU countries as novel food.

Inactivation of Foodborne Viruses by UV Light: A Review

Viruses on some foods can be inactivated by exposure to ultraviolet (UV) light. This green technology has little impact on product quality and, thus, could be used to increase food safety. While its bactericidal effect has been studied extensively, little is known about the viricidal effect of UV on foods. The mechanism of viral inactivation by UV results mainly from an alteration of the genetic material (DNA or RNA) within the viral capsid and, to a lesser extent, by modifying major and minor viral proteins of the capsid. In this review, we examine the potential of UV treatment as a means of inactivating viruses on food processing surfaces and different foods. The most common foodborne viruses and their laboratory surrogates; further explanation on the inactivation mechanism and its efficacy in water, liquid foods, meat products, fruits, and vegetables; and the prospects for the commercial application of this technology are discussed. Lastly, we describe UV’s limitations and legislation surrounding its use. Based on our review of the literature, viral inactivation in water seems to be particularly effective. While consistent inactivation through turbid liquid food or the entire surface of irregular food matrices is more challenging, some treatments on different food matrices seem promising.