Risks and new challenges in the food chain: Viral contamination and decontamination from a global perspective, guidelines, and cleaning.

Even during the continuing world pandemic of severe acute respiratory syndrome coronavirus 2 (SARS CoV-2), consumers remain exposed to the risk of getting infected by existing, emerging, or re-emerging foodborne and waterborne viruses. SARS-CoV-2 is different in that it is transmitted directly via the airborne route (droplets and aerosols) or indirect contact (surfaces contaminated with SARS-CoV-2). International food and health organizations and national regulatory bodies have provided guidance to protect individuals active in food premises from potential occupational exposure to SARS-CoV-2, and have recommended chemicals effective in controlling the virus. Additionally, to exclude transmission of foodborne and waterborne viruses, hygiene practices to remove viral contaminants from surfaces are applied in different stages of the food chain (e.g., food plants, food distribution, storage, retail sector, etc.), while new and enhanced measures effective in the control of all types of viruses are under development. This comprehensive review aims to analyze and compare efficacies of existing cleaning practices currently used in the food industry to remove pathogenic viruses from air, nonfood, and food contact surfaces, as well as from food surfaces. In addition, the classification, modes of transmission, and survival of food and waterborne viruses, as well as SARS-CoV-2 will be presented. The international guidelines and national regulations are summarized in terms of virucidal chemical agents and their applications.

New food safety challenges of viral contamination from a global perspective: Conventional, emerging, and novel methods of viral control.

Food- and waterborne viruses, such as human norovirus, hepatitis A virus, hepatitis E virus, rotaviruses, astroviruses, adenoviruses, and enteroviruses, are major contributors to all foodborne illnesses. Their small size, structure, and ability to clump and attach to inanimate surfaces make viruses challenging to reduce or eliminate, especially in the presence of inorganic or organic soils. Besides traditional wet and dry methods of disinfection using chemicals and heat, emerging physical nonthermal decontamination techniques (irradiation, ultraviolet, pulsed light, high hydrostatic pressure, cold atmospheric plasma, and pulsed electric field), novel virucidal surfaces, and bioactive compounds are examined for their potential to inactivate viruses on the surfaces of foods or food contact surfaces (tools, equipment, hands, etc.). Every disinfection technique is discussed based on its efficiency against viruses, specific advantages and disadvantages, and limitations. Structure, genomic organization, and molecular biology of different virus strains are reviewed, as they are key in determining these techniques effectiveness in controlling all or specific foodborne viruses. Selecting suitable viral decontamination techniques requires that their antiviral mechanism of action and ability to reduce virus infectivity must be taken into consideration. Furthermore, details about critical treatments parameters essential to control foodborne viruses in a food production environment are discussed, as they are also determinative in defining best disinfection and hygiene practices preventing viral infection after consuming a food product.

Effects of Ultraviolet Light and High-Pressure Processing on Quality and Health-Related Constituents of Fresh Juice Products.

Fresh juices are highly popular beverages in the global food market. They are perceived as wholesome, nutritious, all-day beverages. For a fast growing category of premium juice products such as cold-pressed juices, minimal-processing nonthermal techniques such as ultraviolet (UV) light and high-pressure processing (HPP) are expected to be used to extend shelf-life while retaining physicochemical, nutritional, and sensory characteristics with reduced microbial loads. Also, UV light and HPP are approved by regulatory agencies and recognized as one of the simplest and very environmentally friendly ways to destroy pathogenic organisms. One of the limitations to their more extensive commercial application lies in the lack of comparative effects on nutritional and quality-related compounds in juice products. This review provides a comparative analysis using 92 studies (UV light: 42, HPP: 50) mostly published between 2004 and 2015 to evaluate the effects of reported UV light and HPP processing conditions on the residual content or activity of bioactive compounds such as vitamins, polyphenols, antioxidants, and oxidative enzymes in 45 different fresh fruit and vegetable juices (low-acid, acid, and high-acid categories). Also, the effects of UV light and HPP on color and sensory characteristics of juices are summarized and discussed.

Inactivation and potential reactivation of pathogenic Escherichia coli O157:H7 in apple juice following ultraviolet light exposure at three monochromatic wavelengths.

Ultraviolet (UV) light irradiation at 254 nm is considered as a novel non-thermal method for decontamination of foodborne pathogenic bacteria. However, lower penetration depth of UV light at 254 nm in apple juice resulted in higher UV dose consumption during apple juice decontamination. In addition, no studies are available on the reactivation of pathogens following exposure to UV light in drinks and beverages. Two novel monochromatic UV light sources (λ = 222 and 282 nm) have been developed for bacterial disinfection. However, the inactivation of pathogenic Escherichia coli O157:H7 following exposure to these UV wavelengths is still unclear. Therefore, the present study was conducted to determine the inactivation and reactivation potential of pathogenic E. coli O157:H7 in apple juice following exposure to UV light at three monochromatic wavelengths: Far UV (λ = 222 nm), Far UV+ (λ = 282 nm) and UVC light (λ = 254 nm). The results showed that E. coli O157:H7 is acid-resistant, and up to 99.50% of cells survived in apple juice when incubated at 20 °C for 24 h. Inactivation of E. coli O157:H7 following exposure to Far UV light (2.81 Log reduction) was higher (P < 0.05) than the inactivation caused by UVC light (1.95 Log reduction) and Far UV+ light (1.83 Log reduction) at the similar levels of UV fluence of 75 mJ/cm(2). No any reactivation potential was observed for E. coli O157:H7 in dark incubation phases after exposure to UV light as determined by the regular plating method. In addition, the exposure to Far UV light at 222 nm followed by incubating at 37 °C significantly decreased (P < 0.05) the survival of E. coli O157:H7 during dark incubation phase compared to that of UVC and Far UV+ light.

Inactivation and potential reactivation of pathogenic Escherichia coli O157:H7 in bovine milk exposed to three monochromatic ultraviolet UVC lights.

The ultraviolet (UVC) light irradiation has been recently studied as a novel non-thermal treatment method for milk. However, the potential reactivation of microorganisms following exposure to UVC light in milk medium was not studied yet. Therefore, the present study was conducted to determine the inactivation and reactivation of pathogenic Escherichia coli O157:H7 following exposure to UV light at three monochromatic wavelengths (222, 254 and 282 nm) in bovine milk. The results showed that inactivation of E. coli O157:H7 following exposure to the UV light at 254 nm was higher (P < 0.05) than that following exposure at 222 and 282 nm at the same UV fluence of 5, 10 and 20 mJ/cm(2). The reactivation of E. coli O157:H7 was increased as the incubation time and temperature increased regardless of the UV light sources under dark incubation phases. The evaluated reactivation ratios of E. coli O157:H7 following exposure to the UV light at 254 nm in milk were lower (P < 0.05) than that following exposure at 222 nm after 1 to 6, 2 to 5 and 5-6 h incubation at 4, 20 and 37 °C, respectively. Furthermore, at most incubation time points, the reactivation ratio of E. coli O157:H7 following exposure to these three UV light sources were lower (P < 0.05) than that of non-UV treated cells regardless of the incubation temperature. The lowest reactivation ratios of E. coli O157:H7 were observed after milk exposure to the UV light at 254 nm at 4 °C incubation when compared to that following exposure to the UV light at 222 and 282 nm.

Chemical characterization of milk after treatment with thermal (HTST and UHT) and nonthermal (turbulent flow ultraviolet) processing technologies.

As a result of growing interest to nonthermal processing of milk, the purpose of this study was to characterize the chemical changes in raw milk composition after exposure to a new nonthermal turbulent flow UV process, conventional thermal pasteurization process (high-temperature, short-time; HTST), and their combinations, and compare those changes with commercially UHT-treated milk. Raw milk was exposed to UV light in turbulent flow at a flow rate of 4,000L/h and applied doses of 1,045 and 2,090 J/L, HTST pasteurization, and HTST in combination with UV (before or after the UV). Unprocessed raw milk, HTST-treated milk, and UHT-treated milk were the control to the milk processed with the continuous turbulent flow UV treatment. The chemical characterization included component analysis and fatty acid composition (with emphasis on conjugated linoleic acid) and analysis for vitamin D and A and volatile components. Lipid oxidation, which is an indicator to oxidative rancidity, was evaluated by free fatty acid analysis, and the volatile components (extracted organic fraction) by gas chromatography-mass spectrometry to obtain mass spectral profile. These analyses were done over a 14-d period (initially after treatment and at 7 and 14 d) because of the extended shelf-life requirement for milk. The effect of UV light on proteins (i.e., casein or lactalbumin) was evaluated qualitatively by sodium dodecyl sulfate-PAGE. The milk or liquid soluble fraction was analyzed by sodium dodecyl sulfate-PAGE for changes in the protein profile. From this study, it appears that continuous turbulent flow UV processing, whether used as a single process or in combination with HTST did not cause any statistically significant chemical changes when compared with raw milk with regard to the proximate analysis (total fat, protein, moisture, or ash), the fatty acid profile, lipid oxidation with respect to volatile analysis, or protein profile. A 56% loss of vitamin D and a 95% loss of vitamin A content was noted after 7 d from the continuous turbulent flow UV processing, but this loss was equally comparable to that found with traditional thermal processing, such as HTST and UHT. Chemical characterization of milk showed that turbulent flow UV light technology can be considered as alternative nonthermal treatment of pasteurized milk and raw milk to extend shelf life.

Efficacy of Ultraviolet (UV-C) Light in a Thin-Film Turbulent Flow for the Reduction of Milkborne Pathogens.

Nonthermal technologies are being investigated as viable alternatives to, or supplemental utilization, with thermal pasteurization in the food-processing industry. In this study, the effect of ultraviolet (UV)-C light on the inactivation of seven milkborne pathogens (Listeria monocytogenes, Serratia marcescens, Salmonella Senftenberg, Yersinia enterocolitica, Aeromonas hydrophila, Escherichia coli, and Staphylococcus aureus) was evaluated. The pathogens were suspended in ultra-high-temperature whole milk and treated at UV doses between 0 and 5000 J/L at a flow rate of 4300 L/h in a thin-film turbulent flow-through pilot system. Of the seven milkborne pathogens tested, L. monocytogenes was the most UV resistant, requiring 2000 J/L of UV-C exposure to reach a 5-log reduction. The most sensitive bacterium was S. aureus, requiring only 1450 J/L to reach a 5-log reduction. This study demonstrated that the survival curves were nonlinear. Sigmoidal inactivation curves were observed for all tested bacterial strains. Nonlinear modeling of the inactivation data was a better fit than the traditional log-linear approach. Results obtained from this study indicate that UV illumination has the potential to be used as a nonthermal method to reduce microorganism populations in milk.

Harmonization of legislation and regulations to achieve food safety: US and Canada perspective.

Trade in food and food ingredients among the nations of the world is rapidly expanding and, with this expansion, new supply chain partners, from globally disparate geographic regions, are being enrolled. Food and food ingredients are progressively sourced more from lesser developed nations. Food safety incidents in the USA and Canada show a high unfavorable correlation between illness outbreaks and imported foods. In the USA, for example, foodborne disease outbreaks caused by imported food appeared to rise in 2009 and 2010, and nearly half of the outbreaks, associated with imported food, implicated foods imported from areas which previously had not been associated with outbreaks. Projecting supply chains into new geographical regions raises serious questions about the capacity of the new supply chain partners to provide the requisite regulatory framework and sufficiently robust public health measures for ensuring the safety of the foods and foodstuffs offered for international trade. The laws, regulation and legislation among the many nations participating in the global food trade are, at best, inconsistent. These inconsistencies frequently give rise to trade disputes and cause large quantities of food to be at risk of destruction on the often dubious pretext that they are not safe. Food safety is often viewed through a political or normative lens. Often as not, this lens has been wrought absent scientific precision. Harmonization of food safety legislation around sound scientific principles, as advocated by the US Food Safety Modernization Act (FSMA), would ultimately promote trade and likely provide for incremental improvement in public health. Among the priority roles of most national governments are the advancement of commerce and trade, preservation of public health and ensuring domestic tranquility. Achieving these priorities is fundamental to creating and preserving the wealth of nations. Countries such as the Netherlands, Canada, Germany, Japan and the USA, for example, have very stable governments, are leaders in trade and commerce and enjoy high standards of public health. It is not by accident or coincidence that these nations are also among the world's wealthiest. Attainment of national priorities, especially those related to promoting trade in foodstuffs and also in preserving public health (food safety), would benefit greatly from international efforts in harmonizing food safety regulations and legislation.

Kinetics of patulin degradation in model solution, apple cider and apple juice by ultraviolet radiation.

Patulin is a mycotoxin produced by a wide range of molds involved in fruit spoilage, most commonly by Penicillium expansum and is a health concern for both consumers and manufacturers. The current study evaluated feasibility of monochromatic ultraviolet (UV) radiation at 253.7 nm as a possible commercial application for the reduction of patulin in fresh apple cider and juice. The R-52G MINERALIGHT® UV bench top lamp was used for patulin destruction. It was shown that 56.5%, 87.5%, 94.8% and 98.6% reduction of patulin can be achieved, respectively, in the model solution, apple cider, apple juice without ascorbic acid addition and apple juice with ascorbic acid addition in 2-mm thickness sample initially spiked by 1 mg·L(-1) of patulin after UV exposure for 40 min at UV irradiance of 3.00 mW·cm(-2). A mathematic model to compare the degradation rate and effective UV dose was developed. The effective UV doses that were directly absorbed by patulin for photochemical reaction were 430, 674, 724 and 763 mJ·cm(-3), respectively. The fluence-based decimal reduction time was estimated to 309.3, 31.3, 28.9 and 5.1 mW·cm(-2)·min, respectively, in four media mentioned above. The degradation of patulin followed the first-order reaction model. The time-based and fluence-based reaction rate constants were determined to predict patulin degradation. The time-based reaction rate constant of samples treated in dynamic regime with constant stirring (model solution: 2.95E-4 s(-1), juice: 4.31E-4 s(-1)) were significantly higher than samples treated in static regime (model solution: 2.79E-4 s(-1), juice: 3.49E-4 s(-1), p < 0.05) when applied UV irradiance and sample thickness were consistent. The reaction rate constant of patulin degradation in apple juice was significantly higher than model solution (p < 0.05). Although further investigations are still needed, the results of this study demonstrated that UV radiation may be an effective method for treating patulin-containing apple cider and juice.

Resistance of Escherichia coli, Salmonella spp., and Listeria monocytogenes in high and low-acidity juices processed by high hydrostatic pressure.

High-pressure processing (HPP) has emerged in the food industry as an alternative to thermal juice preservation treatments, with its appeal being its assurance of safety for products with nutritional and sensory qualities similar to those of fresh food. However, HPP remains to be fully understood, particularly regarding hazards and process validation to mitigate microbiological risks. One of the challenges is understanding the large variation in the sensitivity of pathogenic strains to pressure associated with microbial genotypes, phenotypes, and food composition. This manuscript provides an overview of barotolerance mechanisms and the influence of pH and soluble solids in low- and high-acidity juices in the resistance of pathogenic strains of Escherichia coli, Salmonella spp., and Listeria monocytogenes, as well as their surrogates. The presented information can be used in the selection of challenge microorganisms for validation tests, including the results of a few studies with tropical and blended fruit and vegetable juices and the influence of the food matrix on the high pressure resistance of pathogenic strains.

Inactivation of Salmonella Enteritidis on Hatchery and Table Eggs Using a Gas-phase Hydroxyl-Radical Process.

Eggs represent a significant vehicle for Salmonella Enteritidis with the pathogen being transferred to chicks in the hatchery, or to consumers via table eggs. In the following, the efficacy of a gas-phase hydroxyl-radical process for decontaminating hatchery and table eggs was evaluated. Recovery of Salmonella was maximized through holding eggs in tryptic soy broth containing 20% w/v glycerol for 1 h prior to plating. By using this technique, it was possible to recover 63% of the theoretical Salmonella inoculated onto eggs. The continuous hydroxyl-radical reactor consisted of a bank of UV-C lamps (254 nm) that generated hydroxyl-radicals from the degradation of hydrogen peroxide (H2O2) mist and ozone gas. The optimal treatment was defined as that which supports a 5 log CFU/egg reduction of Salmonella without negatively affecting egg quality or leaving H2O2 residues. A process of 2% v/v H2O2 delivered at 30 mL/min with a UV-C dose of 19 mJ/cm2 and ozone (20 ppm) with a total treatment time of 10s was selected. The egg quality metrics (Haugh value, yolk index, albumin pH, yolk pH) did not negatively differ over a 35-day shelf-life at 4 or 25℃ compared to washed eggs or nontreated controls. The cuticle layer of eggs remained intact following hydroxyl-radical treatment. Fertilized eggs (n = 61) treated with the hydroxyl-radicals exhibited the same hatchery rate (75%) as nontreated controls (71-79%) with no defects (unhealed navels or red hocks) being observed. The same hydroxyl-radical treatment could be applied to table eggs to support >5 log CFU/egg reduction of Salmonella and was compatible with egg washing regimes practiced in industry. In comparison, the egg washing process based on sodium hydroxide and chlorine supported a 2.76 ± 0.38 log CFU/egg reduction of Salmonella. The hydroxyl-radical treatment represents a preventative control step to reduce the carriage of Salmonella on hatchery and table eggs.

Continuous-flow UV-C processing of kale juice for the inactivation of E. coli and assessment of quality parameters.

Ultraviolet-C (UV-C) light is a non-thermal method for improving the safety and shelf-life of cold-pressed juices with minimal impact on quality and nutrition. Most previous studies have investigated fruit juices as opposed to particulate dense leafy green juices with very low UV transmittance (UVT). Pure kale juice is a common juice ingredient and represents the worst-case scenario in terms of low UVT green juices. This study validated the use of continuous benchtop UV-C treatment at 253.7 nm for 5-log reduction of non-pathogenic Escherichia coli P36 in kale juice. An average absorbed fluence of 108.3 mJ cm-2 resulted in a 5.8 log reduction of E. coli P36. At a fluence comparable to that reported for commercial juice processing (74.0 mJ cm-2), kale juice exhibited a decrease in absorption coefficient, while sedimentation, supernatant browning and pectin methylesterase activity increased with no effect on the chlorophyll content, colour, viscosity or antioxidant content.

Comparative Effects of Thermal, High Hydrostatic Pressure, and UV-C Processing on the Quality, Nutritional Attributes, and Inactivation of Escherichia coli, Salmonella, and Listeria Introduced into Tiger Nut Milk.

HIGHLIGHTS: Thermal and nonthermal methods can support a 5-log CFU reduction of model bacteria introduced into tiger nut milk. Thermal treatment of tiger nut milk results in significant loss of protein, antioxidants, and quality properties. HHP or UV-C treatment of tiger nut milk retains quality and nutritional characteristics. HHP or UV-C are suitable for the pasteurization of tiger nut milk.

Feasibility of 3D UV-C treatment to reduce fungal growth and mycotoxin loads on maize and wheat kernels.

Fungal disease of grain crops is a concern for the agricultural industry, resulting in economic losses. Aside from severe yield losses, mycotoxigenic fungi such as Penicillium and Fusarium can produce harmful mycotoxins, including deoxynivalenol (DON), zearalenone (ZEN), and ochratoxin A (OTA). This proof-of-concept study explored the feasibility and effects of ultraviolet (UV) C light at 253.7 nm to reduce fungal and mycotoxin loads on model surfaces as well as on maize and wheat kernels using benchtop 2D and 3D illumination strategies. Reduction of Penicillium verrucosum (98.6%) and Fusarium graminearum (88.8%) on agar was achieved using a UV-C dose of 100 mJ cm-2. Naturally occurring fungal growth resembling P. verrucosum on maize was reduced by 79% after exposure to 5000 mJ cm-2. Similarly, fungal growth resembling F. graminearum on maize was reduced by 60% with 1000 mJ cm-2. On wheat, significant reduction of fungal growth was not observed. Maximal reduction of DON (97.3%), ZEN (75.4%), and OTA (91.2%) on filter paper was obtained using 15,000 mJ cm-2. The overall reduction of DON (30%; 14%), ZEN (52%; 42%), and OTA (17%; 6%) on maize and wheat, respectively, was lower than on filter paper. Moisture and crude protein content as well as percent germination of maize kernels were not affected by UV-C treatment up to 5000 mJ cm-2. This study has shown that 3D UV-C treatment is a feasible option for reducing Fusarium and Penicillium growth on maize kernels and, at higher doses, decreasing ZEN by ~ 50%.

Suppression of the formation of furan by antioxidants during UV-C light treatment of sugar solutions and apple cider.

Furan, which has been identified as a carcinogenic risk for humans, can be induced in different foods by UV-C light. In this study, we hypothesized that furan was produced by a UV light-induced free radical mechanism and antioxidants could suppress its formation. Our results demonstrated that, by adding antioxidants, such as butylated hydroxyl toluene, ascorbic acid or gallic acid, to simulated juice or apple cider during UV-C treatment, amounts of furan were significantly reduced. For example, the concentration of furan produced in apple cider by UV-C at 9.0 J/cm2 was 636 ppb but was less than 20 ppb with 0.25 ppm butylated hydroxyl toluene present, less than 3 ppb with 0.5% (w/v) ascorbic acid, and less than 1.0 ppb with 0.5% (w/v) gallic acid. These findings confirmed that antioxidants can be used as a safe and simple mitigation measure to control furan production in fruit drinks exposed to UV-light.

Actinometric and biodosimetric evaluation of UV-C dose delivery in annular, Taylor-Coutte and coiled tube continuous systems.

In this study, the evaluation of the performance of two thin-film UV-C reactors (annular and Taylor-Couette) and a coiled tube system is presented using actinometry and biodosimetry methods. The iodide/iodate actinometry method was found suitable for comparison of the efficiency of UV-C dose delivery of the UV-C continuous flow systems. Inactivation kinetics of Escherichia coli ATCC 8739 in quarter-strength Ringer's solution (absorption coefficient α254 nm ∼ 0 cm-1) at various flow conditions at Reynolds numbers in the range of 26 to 3000 showed a good correlation between the different reactor types. In high UV-C absorbing liquids, the inactivation efficiency increases due to the improved radial mixing. The inactivation performance of the Taylor-Couette system correlates to the annular reactor when no rotation force is applied. The residence time distributions showed the narrowest distribution with the coiled tube system at comparable flow rates. The results indicate that, despite the laminar flow conditions, the performance of the Taylor-Couette unit becomes equal to the turbulent flow conditions of the coiled tube reactor by rotation of the inner cylinder.

An efficient method for the simultaneous determination of furan, 2-methylfuran and 2-pentylfuran in fruit juices by headspace solid phase microextraction and gas chromatography-flame ionisation detector.

A headspace solid phase microextraction (HS-SPME) procedure followed by gas chromatography-flame ionisation detector (GC-FID) analysis was developed and validated for the simultaneous analysis of furan, 2-methylfuran and 2-pentylfuran from juice samples. Extraction at 32 °C for 20 min with stirring at 600 rpm and NaCl concentration 15% (W/V) was the optimal HS-SPME condition for all the three compounds by using a carboxen/polydimethylsiloxane fused silica fibre (75 µm). The extracted compounds were base line separated on a SPB-1 GC column within 12 min. The relative standard deviations of all analytes were less than 6.7%. The recovery rates were between 90.2% and 110.1%. The limits of detection and limits of quantification were 0.056-0.23 ng/mL and 0.14-0.76 ng/mL, respectively. The results showed that the developed method was sensitive, precise, accurate and robust for the determination of furan, 2-methylfuran and 2-pentylfuran in complex matrices without interferences from other components.

Effect of salt types and concentrations on the high-pressure inactivation of Listeria monocytogenes in ground chicken.

National and international health agencies have recommended a significant reduction in daily intake of sodium by reducing the amount of NaCl in foods, specifically processed meats. However, sodium reduction could increase the risk of survival and growth of spoilage and pathogenic microorganisms on these products. Therefore, alternate processing technologies to improve safety of sodium reduced foods are necessary. This study examined the effects of three different salt types and concentrations on high-pressure inactivation of Listeria monocytogenes in pre-blended ground chicken formulations. Ground chicken formulated with three salt types (NaCl, KCl, CaCl2), at three concentrations (0, 1.5, 2.5%) and inoculated with a four strain cocktail of L. monocytogenes (10(8) CFU g(-1)) were subjected to four pressure treatments (0, 100, 300, 600 MPa) and two durations (60, 180 s) in an experiment with factorial design. Surviving cells were enumerated by plating on Oxford agar and analysed by factorial ANOVA. Pressure treatments at 100 or 300 MPa did not significantly (P=0.19-050) reduce L. monocytogenes populations. Neither salt type nor concentration had a significant effect on L. monocytogenes populations at these pressure levels. At 600 MPa, salt types, concentrations and duration of pressure treatment all had a significant effect on L. monocytogenes populations. Formulations with increasing concentrations of NaCl or KCl showed significantly lower reduction in L. monocytogenes, while increase in CaCl2 concentration resulted in a significantly higher L. monocytogenes reduction. For instance, increase in NaCl concentration from 0 to 1.5 or 2.5% resulted in a log reduction of 6.16, 2.49 and 1.29, respectively, when exposed to 600 MPa for 60s. In the case of CaCl2, increase from 0 to 1.5 or 2.5% resulted in a log reduction of 6.16, 7.28 and 7.47, respectively. These results demonstrate that high-pressure processing is a viable process to improve microbial safety of sodium reduced poultry products.

Reduction of patulin in apple juice products by UV light of different wavelengths in the UVC range.

This study evaluated three UVC wavelengths (222, 254, and 282 nm) to degrade patulin introduced into apple juice or apple cider. The average UV fluences of 19.6, 84.3, 55.0, and 36.6 mJ·cm(-2) achieved through exposure to UV lamps at 222-, 254-, and 282-nm wavelengths and the combination of these wavelengths, respectively, resulted in 90% reduction of patulin in apple juice. Therefore, the order of efficiency of the three wavelength lamps was as follows: far UVC (222 nm) > far UVC plus (282 nm) > UVC (254 nm). In terms of color, treatment of apple juice with 222 nm resulted in an increase in the L* (lightness) value but decreases in a* (redness) and b* (yellowness) values, although the changes were insignificantly different from the values for nontreated controls based on a sensory evaluation. The ascorbic acid loss in juice treated at 222 nm to support 90% reduction of patulin was 36.5%, compared with ascorbic acid losses of 45.3 and 36.1% in samples treated at 254 and 282 nm, respectively. The current work demonstrated that the 222-nm wavelength possesses the highest efficiency for patulin reduction in apple juice when compared with the reductions by 254 and 282 nm, with no benefit gained from using a combination of wavelengths.

Radio frequency heating of foods: principles, applications and related properties--a review.

Radio frequency (RF) heating is a promising technology for food applications because of the associated rapid and uniform heat distribution, large penetration depth and lower energy consumption. Radio frequency heating has been successfully applied for drying, baking and thawing of frozen meat and in meat processing. However, its use in continuous pasteurization and sterilization of foods is rather limited. During RF heating, heat is generated within the product due to molecular friction resulting from oscillating molecules and ions caused by the applied alternating electric field. RF heating is influenced principally by the dielectric properties of the product when other conditions are kept constant. This review deals with the current status of RF heating applications in food processing, as well as product and system specific factors that influence the RF heating. It is evident that frequency level, temperature and properties of food, such as viscosity, water content and chemical composition affect the dielectric properties and thus the RF heating of foods. Therefore, these parameters should be taken into account when designing a radio frequency heating system for foods.