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Glucokinase (GK), an enzyme critical to glucose metabolism, exhibits thermal instability, which can affect its enzymatic activity under physiological and pathological conditions. This study aims to mathematically model the thermal denaturation kinetics of GK and empirically validate the model using experimental data. To establish a mathematical model on thermal denaturation of glucokinase (E.C.2.7.1.2) and its experimental validation, the enzyme glucokinase was investigated in a 0.075M Tris HCl buffer with pH 9.0 at 30∘C and 0.6M MgCl2. A first-order kinetic model was developed to describe the enzyme’s denaturation, incorporating temperature-dependent reaction rates based on the Arrehenius equation. Empirical data were collected through Spectrophotometer across a temperature range of 20∘–60∘C. Experimental validation revealed that GK undergoes irreversible denaturation above 60∘ with a significant reduction as temperature increases. Moreover, the thermal denaturation of GK in the presence of osmolyte Urea is a critical process affecting enzyme stability and function. This study also aims to mathematically model and empirically validate the impact of Urea on GK’s thermal denaturation behavior. Results demonstrated that Urea significantly reduces the thermal stability of GK, lowering its denaturation temperature. The results are simulated graphically using the Wolfram MATHEMATICA software. The mathematical predictions closely matched experimental data, confirming the model’s accuracy. [ABSTRACT FROM AUTHOR]

The individual and combined effects of electron beam (EB) irradiation and thermal treatments were investigated on Chinese braised beef samples inoculated with Bacillus cereus spores. Log reductions of 1.19, 2.10, and 3.62 log CFU/g were recorded for B. cereus spores after 6, 9, and 12 kGy lone EB doses, respectively. An 85°C thermal treatment at 20 min (H) reduced the spores population by 1.03 log CFU/g. The combination of the thermal and EB irradiation treatments (HEB) of HEB-6 and HEB-9 achieved 1.69 and 2.89 log CFU/g reductions, respectively. The B. cereus spores population was depleted to below the detection limit following HEB-12 treatment. No significant pH change was observed in the treatments except for HEB-12. The hurdle treatment of HEB-12 caused marked changes in color, aroma, and overall acceptability. Although HEB irradiation improved microbial safety, careful selection of approved EB doses can effectively enhance food safety and maintain reasonable quality standards. [ABSTRACT FROM AUTHOR]

The limited understanding of the thermal properties of endo-β-1,4-glucanase poses a significant obstacle to its widespread industrial use. This research was designed to explore the thermodynamic and thermal inactivation of endo-β-1,4-glucanase extracted from Aspergillus niger for industrial applications. In this study, grape bagasse was utilized as the carbon source. Endo-β-1,4-glucanase was derived from Aspergillus niger through a submerged fermentation process. Aspergillus niger endo-β-1,4-glucanase was partially purified to the extent of gel filtration chromatography (Sephadex G-100) with a 2.68% yield and a specific activity of 9.21 U/mg after ammonium sulphate precipitation (50% saturation) and dialysis. Endo-β-1,4-glucanase activity reached its optimal at a pH of 5.0. The enzyme exhibited an optimum activity at temperature of 55°C and a maximum thermostability with a half-life of 364.79 min. Thermodynamic parameters showed that the enthalpy of activation of denaturation (ΔH) was 26.12, 26.04, 25.99, 25.96, 25.92, 25.87, and 25.79 KJ/mol at 40oC, 50oC, 55oC, 60oC, 65oC, 70oC, and 80oC, respectively. A z-value of 0.014oC was obtained, with an activation energy (Ea) of 28.73 KJ/mol for the denaturation of the enzyme indicating the enzyme's responsiveness to a rise in temperature. The D-value of the enzyme ranged from 291.5 to 1212.1 min. The Gibbs free energy was negative (ΔG > 0) at the temperatures studied, while the entropy change was positive (ΔS < 0). The thermodynamic studies showed the thermal deactivation of the enzyme. These characteristics at the optimum conditions and stability of the enzyme make it a promising enzyme for industrial applications, particularly for bioethanol fermentation. [ABSTRACT FROM AUTHOR]

Histidine ammonia-lyase (HAL) plays a pivotal role in the non-oxidative deamination of L-histidine to produce trans-urocanic, a crucial process in amino acid metabolism. This study examines the cloning, purification, and biochemical characterization of a novel HAL from Geobacillus kaustophilus (GkHAL) and eight active site mutants to assess their effects on substrate binding, catalysis, thermostability, and secondary structure. The GkHAL enzyme was successfully overexpressed and purified to homogeneity. Its primary sequence displayed 40.7% to 43.7% similarity with other known HALs and shared the same oligomeric structure in solution. Kinetic assays showed that GkHAL has optimal activity at 85 °C and pH 8.5, with high thermal stability even after preincubation at high temperatures. Mutations at Y52, H82, N194, and E411 resulted in a complete loss of catalytic activity, underscoring their essential role in enzyme function, while mutations at residues Q274, R280, and F325 did not abolish activity but did reduce catalytic efficiency. Notably, mutants R280K and F325Y displayed novel activity with L-histidinamide, expanding the substrate specificity of HAL enzymes. Circular dichroism (CD) analysis showed minor secondary structure changes in the mutants but no significant effect on global GkHAL folding. These findings suggest that GkHAL could be a promising candidate for potential biotechnological applications. [ABSTRACT FROM AUTHOR]

Bee-collected pollen is stored in the colony and mixed with bee saliva and microorganisms, resulting in pollen's fermentation and acidification. Pathogens infecting the colony, including the deformed wing virus (DWV), may be transferred into the bee bread (BB). In this study, we used an in vivo infection assay to determine whether DWV remains infective in BB. We also used Lactobacillus kunkeei to ferment UV-treated fresh pollen. This fermented pollen in vitro (FPV) was used as a virus-free reference for the initial viral loads in BB and to evaluate the effect of controlled bacterial fermentation on the infectivity of DWV. Finally, we investigated the thermal inactivation of DWV in BB and FPV. To accomplish these goals, we added DWV inoculum to BB and FPV and heated them at 70 °C or 60 °C for 1 h. Suspensions of the virus recovered from the treated pollen samples were injected into pupae to evaluate the degree of viral viability and the efficacy of thermal inactivation. We found that the virus recovered from non-thermally treated BB and FPV samples remained highly infectious in the pupal injection assay. Overall, BB and FPV treated at 60 °C had an average reduction of 98.69% of viable DWV copies, while treatments at 70 °C inactivated DWV almost entirely (99.99%). This study demonstrates that DWV remains infective in BB and that thermal inactivation is an effective strategy for significantly reducing levels of viable DWV in contaminated pollen. [ABSTRACT FROM AUTHOR]

Cooking parameters elaborated in the U.S. Department of Agriculture’s Food Safety and Inspection Service Cooking Guideline for Meat and Poultry Products (Appendix A) were evaluated for inactivation of Salmonella spp. in pot pies. To prepare dough for pot pies, flour, butter, sugar, salt, and water were mixed, portioned into balls (65 or 85 g each), flattened (ca. 13 or 15 cm diameter, ca. 0.5 cm thick), and hand-pressed into pans (ca. 19.4 cm diameter). Next, a 100-g portion of beef, chicken, or a meat alternative, with or without added gravy (55 g of protein and 45 g of gravy), was inoculated with a cocktail of Salmonella spp. (ca. 6.5 or 7.9 log CFU/g of filling) and distributed onto the pie crust. After covering with a 65-g sheet of dough, pies were heat sealed in nylon polyethylene bags and stored at −20 °C for up to 72 h. Frozen pot pies containing a beef or meat alternative filling were cooked in a convection oven to an internal temperature of 57.8 °C (136°F) instantaneous, 62.8 °C (145°F) and held for 4 min, 67.2 °C (153°F) and held for 34 sec, or 71.1 °C (160°F) instantaneous; whereas chicken pot pies were cooked to an internal temperature of 57.8 °C (136°F) instantaneous, 62.8 °C (145°F) and held for 13 min, 67.2 °C (153°F) and held for 96 sec, or 73.9 °C (165°F) instantaneous. Cells of Salmonella spp. were recovered from uncooked or cooked pot pies by stomaching each pie in peptone water and enumerating pathogen levels via direct plating. Cooking delivered Salmonella spp. reductions of ca. 3.6 to ≥6.3 log CFU/g of pot pie. With few exceptions, when pathogen levels decreased to below detection by direct plating (0.5 log CFU/g of pot pie), cells of Salmonella were not recovered by enrichment. In addition, there were minimal differences in the aw and moisture content of the protein filling before and after cooking, suggesting that enclosing a meat, poultry, or meat alternative filling within a dough wrapping maintained moisture in the filling during the cooking process.

ObjectiveTo explore the effect of sous-vide on the thermal inactivation rules of Listeria monocytogenes in different matrix， the thermal inactivation of Listeria monocytogenes in different substrates at different temperatures was studied.MethodsFive lyophiliZed L. monocytogenes strains were inoculated into saline， MH broth， vacuum packed lean pork and streaky pork. The survival rates were evaluated at 55， 60， and 63 ℃. The decimal reduction time （D-value） and temperature dependence （Z-value） were determined for each strain in each matrix.ResultsThe D value and Z value of Listeria monocytogenes in pork were higher than those in normal saline and MH broth， the difference was statistically significant （P

Atopic dermatitis, psoriasis and lichen sclerosus are among the most challenging conditions treated by dermatologists worldwide, with potentially significant physical, social and psychological impacts. Emerging evidence suggests that autologous-platelet-rich plasma could be used to manage skin inflammation. However, the presence of soluble autoimmune components could hinder their therapeutic potential. The aim of this study was to analyze the proteomic profile of plasma rich in growth factors (PRGFs) obtained from donors with inflammatory skin conditions to evaluate the impact of skin health status on the composition and bioactivity of PRGF-based treatments. Venous blood from healthy volunteers and patients with psoriasis, lichen sclerosus and atopic dermatitis was processed to produce PRGF supernatant. Half of the samples were subjected to an additional thermal treatment (56 °C) to inactivate inflammatory and immune molecules. Proteomic analysis was performed to assess the protein profile of PRGFs from healthy and non-healthy patients and the effect of Immunosafe treatment. Differential abundance patterns of several proteins related to key biological processes have been identified, including complement activation, blood coagulation, and glycolysis- and gluconeogenesis-related genes. These results also demonstrate that the thermal treatment (Immunosafe) contributes to the inactivation of the complement system and, as a consequence, reduction in the immunogenic potential of PRGF products. [ABSTRACT FROM AUTHOR]

Introduction: There are no microbiological regulatory limits for viruses in animal feed and feed ingredients. Methods: A performance objective (PO) was proposed in this study to manufacture a spray-dried porcine plasma (SDPP) batch absent of any infectious viral particles. The PO levels of −7.0, −7.2, and −7.3 log TCID50/g in SDPP were estimated for three batch sizes (10, 15, and 20 tons). Results and discussion: A baseline survey on the presence of porcine epidemic diarrhea virus (PEDV) in raw porcine plasma revealed a concentration of −1.0 ± 0.6 log TCID50/mL as calculated using a TCID50-qPCR derived standard curve. The mean African swine fever virus (ASFV) concentration in raw plasma was estimated to be 0.6 log HAD50/mL (0.1–1.4, 95% CI) during a pre-clinical scenario (collected from asymptomatic and undetected viremic pigs). Different processing scenarios (baseline: spray-drying + extended storage) and baseline + ultraviolet (UV) radiation were evaluated to meet the PO levels proposed in this study. The baseline and baseline + UV processing scenarios were >95 and 100% effective in achieving the PO for PEDV by using different batch sizes. For the ASFV in SDPP during a pre-clinical scenario, the PO compliance was 100% for all processing scenarios evaluated. Further research is needed to determine the underlying mechanisms of virus inactivation in feed storage to further advance the implementation of feed safety risk management efforts globally. [ABSTRACT FROM AUTHOR]

The objective of this study was to validate a simulated commercial baking process for traditional crust pepperoni pizza to inactivate Salmonella when contamination was introduced through inoculated flour and pepperoni slices. The unbleached flour and pepperoni slices were inoculated (separate studies) with a 3‐serovar Salmonella cocktail and dried back to their respective pre‐inoculation water activity level to achieve 6.14 and 6.84 log CFU/g, respectively. The inoculated traditional crust pizza was baked at 260°C (500 °F) for 12 min followed by 15 min of ambient cooling. In both cases, a >6 log CFU/g reduction in Salmonella population was achieved by the first 8 min of baking. The pH (5.23–5.25) and water activity (0.958 ± 0.001–0.938 ± 0.005) of the pizza in this study did not change significantly. The D‐values of 3‐serovar Salmonella cocktail in traditional crust pepperoni pizza dough were 23.2 ± 1.82, 7.50 ± 0.32, and 2.0 ± 0.15 min at 56°C, 59°C, and 62°C, respectively, with a z‐value of 5.7°C. The study validated that traditional crust pepperoni pizzas when baked at 260°C (500 °F) for at least 12 min will reduce Salmonella populations by ≥5 log CFU/g if prebaking contamination occurs via flour and/ or pepperoni. [ABSTRACT FROM AUTHOR]

ABSTRACT: Salmonella and Campylobacter are major foodborne pathogens that cause outbreaks associated with contaminated chicken liver. Proper cooking is necessary to avoid the risk of illness to consumers. This study tested the thermal inactivation of a 4-strain Salmonella cocktail and a 3-strain Campylobacter cocktail in chicken livers separately at temperatures ranging from 55.0 to 62.5°C. Inoculated livers were sealed in aluminum cells and immersed in a water bath. The decimal reduction time (D-values) of Salmonella in chicken livers were 9.01, 2.36, 0.82, and 0.23 min at 55.0, 57.5, 60.0, and 62.5°C, respectively. The D-values of Campylobacter ranged from 2.22 min at 55.0°C to 0.19 min at 60.0°C. Salmonella and Campylobacter had similar z-values in chicken livers of 4.8 and 4.6°C, respectively. Chicken livers can be heated to internal temperatures of 70.0 to 73.9°C for at least 1.6 to 0.2 s to achieve a 7-log reduction of Salmonella. Validation tests demonstrated that heating chicken livers to internal temperatures of 70.0 to 73.9°C for 2 to 0 s resulted in a reduction of Salmonella exceeding 7 logs. Collectively, these data show that Salmonella exhibits higher heat resistance than Campylobacter in chicken livers. Therefore, Salmonella could be considered as the target pathogen when designing thermal treatments or cooking instructions for liver products. These findings will aid in designing effective thermal processing for both industrial and home cooking to eliminate Salmonella and Campylobacter, ensuring consumer safety when consuming chicken liver products.

With the emergence of clade 2.3.4.4b H5N1 highly pathogenic avian influenza virus (AIV) infection of dairy cattle and its subsequent detection in raw milk, coupled with recent AIV infections affecting dairy farm workers, experiments were conducted to affirm the safety of cooked ground beef related to AIV because such meat is often derived from cull dairy cows. Specifically, retail ground beef (percent lean:fat = ca. 80:20) was inoculated with a low pathogenic AIV (LPAIV) isolate to an initial level of 5.6 log10 50% egg infectious doses (EID50) per 300 g patty. The inoculated meat was pressed into patties (ca. 2.54 cm thick, ca. 300 g each) and then held at 4 °C for up to 60 min. In each of the two trials, two patties for each of the following three treatments were cooked on a commercial open-flame gas grill to internal instantaneous temperatures of 48.9 °C (120°F), 62.8 °C (145°F), or 71.1 °C (160°F), but without any dwell time. Cooking inoculated ground beef patties to 48.9 °C (ave. cooking time of ca. 15 min) resulted in a mean reduction of ≥2.5 ± 0.9 log10 EID50 per 300 g of ground beef as assessed via quantification of virus in embryonating chicken eggs (ECEs). Likewise, cooking patties on a gas grill to 62.8 °C (ave. cooking time of ca. 21 min) or to the USDA FSIS recommended minimum internal temperature for ground beef of 71.1 °C (ave. cooking time of ca. 24 min) resulted in a reduction to nondetectable levels from initial levels of ≥5.6 log10 EID50 per 300 g. These data establish that levels of infectious AIV are substantially reduced within inoculated ground beef patties (20% fat) using recommended cooking procedures.

Background. The aim of this study was to investigate the effect of calcium and sucrose, which are in several cases present in fruit-based foods during food processing, on the thermal inactivation kinetics of pectin methylesterase extracted from tomato fruits. Material and methods. Pectin methylesterase from tomato fruits was extracted using 0.2 M KH2PO4/K2HPO4 buffer containing 1.0 M NaCl (pH 8.0) (1:1 w/v). The activity of pectin methylesterase was determined using an automatic pH-Stat. The thermal inactivation kinetics of the crude tomato pectin methylesterase extract were studied in the absence or presence of calcium (50 mM) or sucrose (20%) in a temperature range of 60°C to 69°C and calculated using non-linear regression analysis (using SAS 9.1 software). Results. The thermal inactivation of tomato pectin methylesterase followed a fractional-conversion kinetic model, indicating the presence of a first-order inactivating thermal sensitive PME fraction and the occurrence of a thermostable PME fraction. Tomato pectin methylesterase is more stable in thermal treatment compared to pectin methylesterase extracted from other fruits. Calcium and sucrose retarded the inactivation of pectin methylesterase but did not change the behavior of the enzyme during thermal treatments. Conclusion. Calcium and sucrose had protective effects on pectin methylesterase activity during thermal treatments. This finding is a good point of reference for food processors working in the area of fruit juice processing. [ABSTRACT FROM AUTHOR]

The laboratory inoculation techniques should ideally mimic the real‐life environment to reliably estimate the decimal reduction time (D‐value) of bacteria for process validation. This study aims at investigating the influence of the inoculation method on the D‐value of Salmonella in black pepper powder. Whole black peppercorns were either inoculated prior to grinding (pre‐grinding procedure) or ground and then inoculated (post‐grinding procedure). The ground black pepper was thermaly treated at 80°C for 0‐30 min. The D80°C values of Salmonella inoculated by pre‐grinding and post‐grinding procedures were 5.5 ± 0.8 and 3.9± 0.3, respectively. Salmonella and E. faecium were significantly (p⟨0.05) more thermally resistant in ground black pepper when inoculated pre‐ rather than post‐grinding. Therefore, inoculation protocol must be considered by spice industries while validating the pasteurization process. E. faecium is a suitable surrogate for Salmonella because of its higher decimal reduction time for both inoculation methods. [ABSTRACT FROM AUTHOR]

A validation study was conducted to investigate the effect of the English muffin baking process to control Salmonella contamination and to study the thermal inactivation kinetic parameters (D- and z-values) of Salmonella in English muffin dough. The unbleached bread flour was inoculated with 3 serovar Salmonella cocktail (Salmonella serovars viz., Newport, Typhimurium, and Senftenberg), and dried back to its preinoculated water activity levels with 7.46 ± 0.12 log CFU/g of Salmonella concentration. The Salmonella inoculated flour was used to prepare English muffin batter and baked at 204.4°C (400°F) for 18 min and allowed to cool at ambient air for 15 min. The English muffins reached 99 ± 0°C (211.96 ± 0.37°F) as their maximum mean internal temperature during baking. The pH and aw of English muffin dough were 5.01 ± 0.01 and 0.947 ± 0.003, respectively. At the end of the 18−min baking period, the Salmonella inoculated English muffins recorded a more than 5 log CFU/g reduction on the injury-recovery media. The D-values of 3 serovar cocktails of Salmonella at 55, 58.5, and 62°C were 42.0 ± 5.68, 15.6 ± 0.73, and 3.0 ± 0.32 min, respectively; and the z-value was 6.2 ± 0.59°C. The water activity (aw) of the English muffin crumb (0.947 ± 0.003 to 0.9557 ± 0.001) remained statistically unchanged during baking, whereas the aw of the muffin crust decreased significantly (0.947 ± 0.003 to 0.918 ± 0.002) by the end of 18 min of baking. This study validates and documents the first scientific evidence that baking English muffins at 204.4°C (400°F) for 18 min acts as an effective kill step by controlling Salmonella population by >5 log CFU/g.

IntroductionThere are no microbiological regulatory limits for viruses in animal feed and feed ingredients.MethodsA performance objective (PO) was proposed in this study to manufacture a spray-dried porcine plasma (SDPP) batch absent of any infectious viral particles. The PO levels of −7.0, −7.2, and −7.3 log TCID50/g in SDPP were estimated for three batch sizes (10, 15, and 20 tons).Results and discussionA baseline survey on the presence of porcine epidemic diarrhea virus (PEDV) in raw porcine plasma revealed a concentration of −1.0 ± 0.6 log TCID50/mL as calculated using a TCID50-qPCR derived standard curve. The mean African swine fever virus (ASFV) concentration in raw plasma was estimated to be 0.6 log HAD50/mL (0.1–1.4, 95% CI) during a pre-clinical scenario (collected from asymptomatic and undetected viremic pigs). Different processing scenarios (baseline: spray-drying + extended storage) and baseline + ultraviolet (UV) radiation were evaluated to meet the PO levels proposed in this study. The baseline and baseline + UV processing scenarios were >95 and 100% effective in achieving the PO for PEDV by using different batch sizes. For the ASFV in SDPP during a pre-clinical scenario, the PO compliance was 100% for all processing scenarios evaluated. Further research is needed to determine the underlying mechanisms of virus inactivation in feed storage to further advance the implementation of feed safety risk management efforts globally.

A wide range of drying parameters and methods are used by industry to produce dried apples. To ensure end-product safety and regulatory compliance, it is essential to evaluate the effectiveness of such industrial practices on microbial inactivation. Therefore, the objective of this study was to evaluate the effects of drying air temperature and velocity on Listeria monocytogenes inactivation during drying of apple slices. Apples (cv. Gala) were cored, sliced as rings (∼6 mm thick), and surface-inoculated with broth-grown culture of an 8-strain cocktail of L. monocytogenes to achieve an inoculation level of 8.6 ± 0.3 log CFU/g. Apple rings were dried in batches using dry air in a pilot-scale impingement oven at 60 or 80 °C air temperature and 0.7 or 2.1 m/s air velocity, and sampled every 30 min for bacterial enumeration, water activity (aw), and moisture content analysis. L. monocytogenes reduction increased (P

Thermal inactivation studies were undertaken on Listeria monocytogenes and Salmonella spp. inoculated on the surface of country ham. Hams (average = ca. 3.4 ± 0.5 kg each; average = ca. ≥18% shrinkage) were used as provided by the processor (i.e., “salted hams”), desalted in tap water (i.e., “desalted hams”), or dried for an additional period (i.e., “extra-dried hams”). Hams were surface inoculated (ca. 9.5 log CFU/ham) with a multistrain cocktail of L. monocytogenes or Salmonella spp. and cooked within a bag in a circulating water bath to an internal temperature of 130°F (54.4°C) instantaneous, 145°F (62.8°C) and held for 4 min, 153°F (67.2°C) and held for 34 s, or 160°F (71.1°C) instantaneous. Regardless of ham type, all four time and temperature combinations tested herein delivered a ≥6.7-log reduction of cells of L. monocytogenes or Salmonella spp. Differences in product pH, moisture content, or aw did not have an appreciable impact on the thermal inactivation of L. monocytogenes or Salmonella spp. on country ham. In addition, shelf-life studies were undertaken using slices of “salted” country ham that were surface inoculated (ca. 5.5 log CFU/slice) with a multistrain cocktail of L. monocytogenes or Staphylococcus aureus and then stored at 20°C. Levels of S. aureus increased by ca. ≤1.4 log CFU/slice during storage for 90 days, whereas levels of L. monocytogenes remained relatively unchanged (≤0.2 log CFU/slice increase). Our data validated that cooking parameters elaborated in the U.S. Department of Agriculture’s Food Safety and Inspection Service Cooking Guideline for Meat and Poultry Products (Revised Appendix A) are sufficient to deliver significant reductions (ca. ≥6.8 log CFU/ham) in levels of L. monocytogenes and Salmonella spp. on country ham. In addition, in the event of postprocessing contamination, country ham may support the outgrowth of S. aureus or survival of L. monocytogenes during storage at 20°C for 90 days.

This paper proposes a novel dust separation and thermal inactivation system that couples an electromagnetic induction heating coil with a cyclone separator. The idea is aimed at the thermal inactivation of potential microorganisms (viruses and other pathogens) associated with dust-laden gas streams, particularly from road surfaces. The integrated system was tested in an experimental setup as a proof-of-concept investigation at different cyclone-induction heating temperatures of 100–400 °C (373–673 K) and air discharge flow velocities of 5–30 m/s. In addition, the influence of operating parameters such as cyclone heating temperature (as induction heating inputs), inlet air velocity, and heating time on the efficacy of the induction heating process were investigated. The time-averaged temperature measurements along the axial direction (z-down) showed predominant temperature fluctuations in the cylinder and cone sections for all cases, especially when the gas plummets down the cyclone. Temperature was highest in the conical section (z = 525 mm) at 320 °C (593 K) at 5 m/s and lowest in the outlet section (z = 375 mm) at 185 °C, which was expected. The results show that inlet air velocity plays a crucial role in affecting temperature dynamics. Conclusive results indicate that with increasing temperature, pressure drop decreases significantly. Along with the experimental results, multiple regression indices using an Artificial Neural Network (ANN) modeling were used to predict the cyclone's induction heating performance, showing good prediction quality in terms of the mean square errors (MSE and RMSE) and the correlation coefficient R2: 0.99. The study demonstrates the technical viability of integrating induction heating coil to a cyclone separator for wide temperature applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Salmonella spp. is a significant foodborne pathogen present in raw meat products and in the processing environment. It can be eliminated by thermal processes such as cooking. Time and temperature in the thermal process play an important role in eliminating this pathogen. The objective of this study is to determine the D- and z-values of Salmonella spp. in whole-muscle beef using the isothermal inactivation method in four temperatures at designated time intervals. Whole-muscle beef was inoculated with 7 to 8 log10 CFU/mL of Salmonella Typhimurium and Salmonella Enteritidis. The inoculated meat samples were heat treated at 58 °C, 60 °C, 62 °C, and 64 °C. At each temperature, Salmonella spp. survival rate was plotted and the D- and z-values were obtained by linear regression of the survival curve. The D-values for the thermal inactivation of whole-muscle beef are D58 °C=5.41 min, D60 °C=2.03 min, D62 °C=0.46 min, and D64 °C=0.18 min, while the z-value obtained was 3.94 °C. These findings will assist food processors in designing the critical limits on the critical control points of the cooking process that ensure safety against Salmonella spp. in cooked whole-muscle beef. [ABSTRACT FROM AUTHOR]

The contamination and spoilage of heat-treated fruit juices by heat-resistant mold ascospores present significant challenges to the food industry. Understanding effective strategies to mitigate this contamination is vital for ensuring the shelf-life and microbial safety of heat-treated fruit juices. This study investigated the thermal resistance of ascospores from different heat-resistant mold species, including Aspergillus laciniosus, A. chevalieri, A. denticulatus, A. siamensis, Hamigera pallida, and Talaromyces macrosporus, isolated from pineapple and sugarcane field soils. Ascospores inactivation kinetics in pineapple juice under heat treatment (75–97 °C) were analyzed using log-linear and Weibull models. Among these species, A. laciniosus displayed the highest heat resistance (δ-value: 104.59 min at 85 °C), while A. siamensis exhibited the lowest (δ-value: 3.39 min at 80 °C). Furthermore, A. laciniosus, the most heat-resistant species, showed notable tolerance to sanitizers. The most effective inactivation was achieved using 1.0% (w/v) sodium hypochlorite for 15 min. Chlorine dioxide, however, was generally ineffective and even activated dormant ascospores in some cases. The combination of hot water (65 °C for 5 min) with sanitizer increased ascospore reduction in most species but did not achieve the 3-log reduction required by the European Standard N13697. This study revealed a correlation between ascospore resistance to heat and chlorine dioxide, offering significant findings for practical inactivation strategies. [ABSTRACT FROM AUTHOR]

Simple Summary: Methicillin-resistant Staphylococcus aureus (MRSA) is a mastitis pathogen in dairy cows. It is common on dairy farms to feed calves milk that cannot be marketed for human consumption for various reasons. Thus, one possible route of MRSA transmission into young stock is via the feeding of contaminated colostrum or raw milk. The aim of our study was to evaluate whether heat treatment of colostrum or raw milk prior to feeding will eliminate MRSA from the colostrum/raw milk and therefore reduce the risk of introducing MRSA into the calf population during the feeding process. We demonstrate that heating colostrum or raw milk at 60 °C causes a substantial reduction in MRSA in these two matrices. However, depending on the MRSA concentration, it may not be sufficient to eliminate all viable MRSA and heat-resistant MRSA can multiply again. Thus, heated colostrum and raw milk should be fed to the calves shortly after the treatment to avoid re-growth of viable MRSA. Methicillin-resistant Staphylococcus aureus (MRSA) may cause difficult-to-treat infections in dairy cattle. One possible route of MRSA transmission into calves is via the feeding of contaminated waste milk. We tested the heat resistance of 17 MRSA strains isolated from German dairy farms in colostrum and raw milk in a laboratory approach. Heating colostrum or raw milk at 60 °C for 30 min eliminated all viable MRSA in the milk, provided the MRSA inoculation rate is low (103 cfu mL−1). In contrast, raw milk highly inoculated with MRSA (106 cfu mL−1) required a holding time of at least 30 min at 70 °C to fully eliminate MRSA from it. However, quantitative analysis showed that a heat treatment for 10 min at 60 °C already significantly reduced the number of viable MRSA in highly inoculated raw milk. Heating colostrum and raw milk above 60 °C may destroy immunoglobulins which are crucial for the calf's health. Therefore, we suggest that colostrum and raw milk that is to be fed to calves on MRSA-positive dairy farms is heated at 60 °C for at least 10 min to reduce the likelihood of transmitting MRSA. In addition, the 60 °C heat-treated colostrum/raw milk should be fed to the calves as soon as possible to avoid re-growth of viable MRSA. [ABSTRACT FROM AUTHOR]

Tomato brown rugose fruit virus (ToBRFV) is a contact-transmitted tobamovirus affecting many tomato growing regions of the world. This study investigated the effects of different glasshouse surfaces on the survival of the virus; the efficacy of different disinfectants; and heat treatment against ToBRFV (surfaces included steel, aluminium, hard plastic, polythene, glass and concrete). A bioassay followed by ELISA was used to check virus viability. ToBRFV survived for at least 7 days on all surfaces tested and on some for at least 6 months. The virus survived for over two hours on hands and gloves. Hand washing was shown to be unreliable for the removal of the virus. Glutaraldehyde and quaternary ammonium compound disinfectants were effective at one hour on all surfaces. Some other disinfectants were effective at one hour of contact time, on all surfaces except concrete. Sodium hypochlorite was partially effective against ToBRFV, even on concrete. A 5 min soak of plastic trays in water at 90 °C was effective at denaturing ToBRFV; however, 5 min at 70 °C was not. Heating infected sap showed the thermal inactivation point to be 90 °C, confirming the hot water treatment results and showing that deactivation was due to the heat treatment and not a washing effect of the water. [ABSTRACT FROM AUTHOR]

Inactivation is a crucial step in the production of postbiotics, with thermal inactivation being the prevailing method employed. Nevertheless, the impact of thermal treatment on bioactivity and chemical composition remains unexplored. The objective of this study was to assess the influence of heating temperature on the antioxidant, anti-inflammatory properties and the chemical composition of ET-22 and BL-99 postbiotics. The findings revealed that subjecting ET-22 and BL-99 to thermal treatment ranging from 70 °C to 121 °C for a duration of 10 min effectively deactivated them, leading to the disruption of cellular structure and release of intracellular contents. The antioxidant and anti-inflammatory activity of ET-22 and BL-99 postbiotics remained unaffected by mild heating temperatures (below 100 °C). However, excessive heating at 121 °C diminished the antioxidant activity of the postbiotic. To further investigate the impact of thermal treatments on chemical composition, non-targeted metabolomics was conducted to analyze the cell-free supernatants derived from ET-22 and BL-99. The results revealed that compared to mild inactivation at temperatures below 100 °C, the excessive temperature of 121 °C significantly altered the chemical profile of the postbiotic. Several bioactive components with antioxidant and anti-inflammatory properties, including zomepirac, flumethasone, 6-hydroxyhexanoic acid, and phenyllactic acid, exhibited a significant reduction in their levels following exposure to a temperature of 121 °C. This decline in their abundance may be associated with a corresponding decrease in their antioxidant and anti-inflammatory activities. The cumulative evidence gathered strongly indicates that heating temperatures exert a discernible influence on the properties of postbiotics, whereby excessive heating leads to the degradation of heat-sensitive active constituents and subsequent diminishment of their biological efficacy. [ABSTRACT FROM AUTHOR]

There is a growing interest in using models to predict foodborne pathogen inactivation as a way to validate or verify preventive controls. Unlike liquid foods, solid, low water activity foods (LWAF) are heterogenous in composition and structure and do not transfer heat uniformly. Using models constructed from one food to predict pathogen inactivation on another LWAF is complex and may not always be possible, even if the foods have similar composition. Using models constructed from inactivation kinetics of three foodborne pathogens and a surrogate from vacuum-steam-pasteurized (72 and 82 °C) whole macadamia nuts and dried apricot halves, 3-log reductions were predicted for the same pathogens and foods of reduced size. Model fits (First-order, Weibull, and Gompertz) were significantly impacted by the food type regardless of particle size. Despite the foods being identical in composition with particle size as the only altered characteristic, best-fit models accurately predicted the 3-log reductions only 50% of the time, but the surrogate inactivation models provided conservative predictions for pathogen reductions, highlighting that a surrogate's model may be a suitable tool for predicting pathogen reduction on LWAFs.

Mild cooking thermal treatments, like sous-vide, can compromise ground meat entrees such as meatballs with chipotle sauce, especially when salt levels are reduced during its preparation. Listeria monocytogenes is a thermoresistant pathogen that can be in ready-to-eat food. On the other hand, nisin, due to its thermal stability, can be a good alternative to aid on the thermal inactivation of L. monocytogenes and ensure meat safety. The objective was to optimize the amount of nisin and salt concentrations to thermally inactivate L. monocytogenes during the sous-vide cooking of ground beef marinated in chipotle sauce, and to generate a predictive model. A four-strain cocktail was prepared and inoculated in ground beef in combination (3:2) with chipotle sauce added with nisin (0–150 IU) and salt (0–2%). After that, meat samples were sous-vide cooked at different temperatures, nisin, and salt concentrations, established by a central composite design. Depending on the levels of these factors, D-values ranged from 49.71 to 0.27 min. A predictive model (p

Spore forming microorganisms pose significant challenges in the food industry, contributing to spoilage and foodborne illnesses. Despite the unfavourable pH conditions of acid foods, certain acid-resistant spore forming bacteria and moulds have shown their capacity to grow, and thereby posing quality and safety concerns. This review discusses our current knowledge of different spore forming bacteria, including Alicyclobacillus spp., Bacillus spp., and Clostridium spp., as well as ascospore producing moulds such as Byssochlamys spp., Neosartorya spp., and Talaromyces spp., involved in the spoilage of various acid food products. The main concerning attribute increasing the spoilage risk of these microorganisms, together with their acid resistance, is their resistance to heat, a primary preservation method employed in shelf stable acid foods. Therefore, particular emphasis has been given to the heat resistance of those spore formers. This review consolidates diverse research findings on the heat resistance of spores/ascospores derived from these spoilage microorganisms. It highlights the complexity of inactivation kinetics influenced by spore associated and heating-medium associated factors. Moreover, how certain spoilage spore formers might raise food safety concerns by creating conductive environments for pathogens in acid foods is being discussed. The lack of knowledge on the spoilage potential and heat resistance of certain spore formers in acid foods, as well as the need for future research to identify the potential spoilage risk of spore formers in novel acid foods, are also highlighted. Overall, this review highlights the challenges posed by spore forming bacteria and moulds in acid foods, shedding light on their heat resistance, spoilage potential, and implications for food quality and safety. [ABSTRACT FROM AUTHOR]

The series-connected building-integrated photovoltaic/thermal (BIPVT) system can significantly increase the terminal temperature and achieve both power generation and heating. However, its utilization of thermal energy is limited. Airborne infectious diseases threaten indoor occupant health. Pathogenic microorganisms can be thermally inactivated, and the effectiveness of inactivation is positively correlated with exposure temperature and duration. Therefore, series-connected BIPVT system has the potential for air thermal disinfection. Based on this, a multifunctional series-connected BIPVT system that provides heating, power generation, and air purification is proposed. However, these three outputs conflict with each other, and there is a lack of optimized design strategies to maximize the system's overall output. In response, this paper develops a multi-objective optimization strategy for the system and optimizes its design across different climate zones. The main content is as follows: (1) Compared with single-stage systems, series systems can significantly improve air purification performance. The series-connected BIPVT system with the best air purification effect can increase the single-pass inactivation ratio to 100 % under the irradiance of 600 W/m2 (2) The glazed photovoltaic/thermal-glazed solar thermal system has the best thermal performance and air purification performance, the thermal efficiency is 38.1 % and the clean air delivery rate is 98.6 m3/h under the irradiance of 800 W/m2 (3) Compared to single-objective optimization and non-optimized designs, the multi-objective optimization design achieves the highest technique for order of preference similarity to the ideal solution (TOPSIS) score, which is 0.5968. • A disinfection-enhanced type multi-functional BIPVT system was proposed. • A two-dimensional mathematical model of the system was established and verified. • The performance of different BIPVT systems was compared. • The system design was optimized by a multi-objective approach. [ABSTRACT FROM AUTHOR]

The contamination and spoilage of heat-treated fruit juices by heat-resistant mold ascospores present significant challenges to the food industry. Understanding effective strategies to mitigate this contamination is vital for ensuring the shelf-life and microbial safety of heat-treated fruit juices. This study investigated the thermal resistance of ascospores from different heat-resistant mold species, including Aspergillus laciniosus, A. chevalieri, A. denticulatus, A. siamensis, Hamigera pallida, and Talaromyces macrosporus, isolated from pineapple and sugarcane field soils. Ascospores inactivation kinetics in pineapple juice under heat treatment (75–97 °C) were analyzed using log-linear and Weibull models. Among these species, A. laciniosus displayed the highest heat resistance (δ-value: 104.59 min at 85 °C), while A. siamensis exhibited the lowest (δ-value: 3.39 min at 80 °C). Furthermore, A. laciniosus, the most heat-resistant species, showed notable tolerance to sanitizers. The most effective inactivation was achieved using 1.0% (w/v) sodium hypochlorite for 15 min. Chlorine dioxide, however, was generally ineffective and even activated dormant ascospores in some cases. The combination of hot water (65 °C for 5 min) with sanitizer increased ascospore reduction in most species but did not achieve the 3-log reduction required by the European Standard N13697. This study revealed a correlation between ascospore resistance to heat and chlorine dioxide, offering significant findings for practical inactivation strategies.

Frozen berries have been repeatedly linked to acute gastroenteritis caused by norovirus, the most common cause of foodborne illness in the United States. Many guidelines recommend that frozen berries be microwaved for at least 2 min, but it is unclear if this thermal treatment is effective at inactivating norovirus. The objective of this study was to model the effect of microwave heating at varying power levels on the survival of bacteriophage MS2, a norovirus surrogate, when inoculated onto frozen strawberries. Bacteriophage MS2 was inoculated onto the surface of frozen strawberries with a starting concentration of approximately 10 log PFU/g. Samples (either 3 or 5 whole strawberries) were heated in a 1300-Watt domestic research microwave oven (frequency of 2450 MHz) at power levels of 30, 50, 70, and 100% (full power), for times ranging from 15 to 300 s to determine inactivation. Temperatures at berry surfaces were monitored during heating using fiberoptic thermometry. All experiments were conducted in triplicate. The primary model for thermal inactivation was a log-linear model of logN vs. time. The secondary model was for a D-value decreasing linearly with temperature and an added term that was path-dependent on the thermal history. Parameters in the model were estimated using dynamic temperature history at the surface of the berry, via nonlinear regression using all data simultaneously. The root mean square error was ∼0.5 PFU/g out of a total 6-log reduction. Log reductions of 1.1 ± 0.4, 1.5 ± 0.5, 3.1 ± 0.1, and 3.8 ± 0.2 log PFU/g were observed for 30, 50, 70, and 100% microwave power levels when three berries were heated for 60 s. D-values were 21.4 ± 1.95 s and 10.6 ± 1.1 s at 10 and 60°C, respectively. This work demonstrates an approach to estimate inactivation parameters for viruses from dynamic temperature data during microwave heating. These findings will be useful in predicting the safety effect of microwave heating of berries in the home or food service.

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A mathematical model for estimating the characteristics of the process of thermal inactivation of vegetative bacterial cells and their spores is presented. The model relates the change rate of the number of living cells as a nonlinear kinetic dependence of the p-th order, and the temperature constant of their inactivation rate is the Arrhenius function. A method for solving the inverse kinetic problem of identifying the parameters of this model from experimental data is proposed. The method is implemented through the minimization of the original functional, which reduces the number of variable parameters. The solution results of inverse problems for determining the kinetic model parameters based on the experimental data of thermal inactivation of bacterial spores B. subtilis and B. anthracis are presented. The obtained parameters are used to solve the direct problems of the dynamics of micro-organism inactivation. The calculation results represent the dependence on the time of the change number of inactivated micro-organisms, and the thermal exposure time for 99% of their deaths at different temperatures. A comparison of the results with other authors' calculations and experimental data confirms the adequacy of the model, the high accuracy of the new solution method and the algorithm for its implementation. The developed model of thermal sterilization can be used for the selective deactivation of pathogens in the food products. [ABSTRACT FROM AUTHOR]

This study aimed at designing, prototyping and testing the effectiveness of a solar disinfection system for improved rural household water treatment. The system was constructed using local materials. The effectiveness and efficiency of the system to kill microorganisms were determined by using contaminated raw water samples collected from rural areas. The prototype raised the bottle water temperature from 24.3 to 66 °C. After 3 hours of exposure to intense sunlight, the water samples registered no total and faecal coliform counts in line with allowable drinking water limits by Malawi Standards and the World Health Organization. When loaded with 12 L of the contaminated water, the system scored a 10.2 % efficiency. The prototype reached disinfecting temperature faster (80 minutes) under intense sunlight conditions and worked effectively well with water of low turbidity levels. The prototype was cost-effective and easy to use, hence to be promoted for improved rural household water treatment.

Background: Inulinase is widely found in microorganisms and higher plants. It catalyzes the reaction of the hydrolysis of inulin, which is present in the tubers and roots of many plants, to fructose and a small amount of glucose. Inulin is one of several plant-based polysaccharides that contain glucose or fructose. It is used as a substrate in industrial fermentation processes and in the food industry due to its relatively cheap and abundant source for the microbiological production of high fructose juices, ethanol, acetone and butanol. Inulin-derived oligosaccharides are also used in the medical and food sectors. Inulinase which produced from the yeast K. marxianus at levels close to commercial use. This indicates that inulinase can be used in the production of fructose and fructose syrups. So our main object is to study the effect of different temperatures on the conformation of the Kluyveromyces marxianus inulinase macromolecule, to provide optimal conditions for aniline hydrolysis by inulinase. Materials and method: Method of isolation and purification of the inulinase enzyme from Kluyveromyces marxianus, as well as the determination of the protein content and enzyme activity as mentioned in the context of the research. Experiments were carried out to study the thermal stability of enzyme. For this, an enzyme solution at a concentration of 5•10-5 mol / l was incubated in a time interval of 10-60 min at different temperatures, followed by determination of the catalytic activity. It is known that different types of bonds and interactions participate in the formation of the molecular structure of enzymes, which are covalent bonds, hydrogen bonds, salt bridges, hydrophobic interactions, so our main goal is to study the effect of different temperatures on the formation of the enzyme molecule in order to provide optimal conditions for aniline hydrolysis. by enzyme. Results: of this study revealed that the residual activity of the enzyme after 60 minutes of incubation at 50 °C was 10% of the initial activity at 60 °C 7%. As for the Rate Constants of thermal inactivation of Inulinase at 70 °C were 3.45. Conclusions: Results of this study were important and useful in determining parameters of inulinase enzyme. Based on the shape of the curves of the dependence of the catalytic activity of Kluyveromyces marxianus inulinase on the time of thermal inactivation in the temperature range of 20-80 ° C.

Inactivation is a crucial step in the production of postbiotics, with thermal inactivation being the prevailing method employed. Nevertheless, the impact of thermal treatment on bioactivity and chemical composition remains unexplored. The objective of this study was to assess the influence of heating temperature on the antioxidant, anti-inflammatory properties and the chemical composition of ET-22 and BL-99 postbiotics. The findings revealed that subjecting ET-22 and BL-99 to thermal treatment ranging from 70 °C to 121 °C for a duration of 10 min effectively deactivated them, leading to the disruption of cellular structure and release of intracellular contents. The antioxidant and anti-inflammatory activity of ET-22 and BL-99 postbiotics remained unaffected by mild heating temperatures (below 100 °C). However, excessive heating at 121 °C diminished the antioxidant activity of the postbiotic. To further investigate the impact of thermal treatments on chemical composition, non-targeted metabolomics was conducted to analyze the cell-free supernatants derived from ET-22 and BL-99. The results revealed that compared to mild inactivation at temperatures below 100 °C, the excessive temperature of 121 °C significantly altered the chemical profile of the postbiotic. Several bioactive components with antioxidant and anti-inflammatory properties, including zomepirac, flumethasone, 6-hydroxyhexanoic acid, and phenyllactic acid, exhibited a significant reduction in their levels following exposure to a temperature of 121 °C. This decline in their abundance may be associated with a corresponding decrease in their antioxidant and anti-inflammatory activities. The cumulative evidence gathered strongly indicates that heating temperatures exert a discernible influence on the properties of postbiotics, whereby excessive heating leads to the degradation of heat-sensitive active constituents and subsequent diminishment of their biological efficacy.

A study was conducted to validate a simulated traditional crust pepperoni pizza baking process to control Shiga toxin-producing Escherichia coli (STEC) and to determine the heat resistance characteristics of STEC in pizza dough. Pizza dough and pepperoni slices were inoculated with 7 strains STEC cocktail and baked at 500°F (260°C) for 12 min using a conventional kitchen oven followed by 15 min of ambient air cooling. The mean internal temperature of the pizza reached 209.32 ± 1.94°F by the end of 12 min of baking and dropped to 137.90 ± 2.88°F after the 15 min ambient air cooling. The aw and pH of the traditional crust pizza did not alter significantly during the baking process. The STEC population decreased by >5 log CFU/g in traditional crust pizza after 12 min of baking. Where pepperoni slices were used as a source of STEC introduction, a reduction of >6.5 log CFU/g was observed. The D-values of STEC cocktail in pizza dough at 55, 58, 61°C were 49.5 ± 4.10, 15.3 ± 0.68, and 2.8 ± 0.31 min, respectively. The z-value of STEC was 4.8 ± 0.16°C. This study validated that a typical traditional crust pizza baking process with ~209°F internal temperature for at least 12 min will result in 5 log reductions in STEC population. [ABSTRACT FROM AUTHOR]

Summary: This study aimed to evaluate the thermal inactivation kinetics of polyphenol oxidase (PPO) and peroxidase (POD) in starfruit juice. It followed the Malaysia Food Regulations 1985 and CODEX STAN 247‐2005. Glucose, fructose and sucrose were the main sugars in starfruit juice. The total soluble solids, pH, titratable acidity, and total phenolics content of the starfruit juice produced were 8.13 ± 0.25 °Brix, 3.80 ± 0.05, 0.43% ± 0.02% malic acid, and 93.67 ± 4.96 mg GAEL−1, respectively. Thermal inactivation kinetics of PPO and POD followed the first‐order kinetic model. The decimal reduction time at 83.6 °C (D83.6) of PPO and POD was 198.48 and 98.4 s, respectively, while the thermal resistance constant (z value) of PPO and POD was 12.8 and 5.4 °C, respectively. In conclusion, PPO might be a suitable signal for thermal processing on starfruit juice since it has higher heat resistance than POD. [ABSTRACT FROM AUTHOR]

The evaluation of temperature effects on the structure and function of enzymes is necessary to understand the mechanisms underlying their adaptation to a constantly changing environment. In the current study, we investigated the influence of temperature variation on the activity, structural dynamics, thermal inactivation and denaturation of Photobacterium leiognathi and Vibrio harveyi luciferases belonging to different subfamilies, as well as the role of sucrose in maintaining the enzymes functioning and stability. We used the stopped-flow technique, differential scanning calorimetry and molecular dynamics to study the activity, inactivation rate, denaturation and structural features of the enzymes under various temperatures. It was found that P. leiognathi luciferase resembles the properties of cold-adapted enzymes with high activity in a narrow temperature range and slightly lower thermal stability than V. harveyi luciferase, which is less active, but more thermostable. Differences in activity at the studied temperatures can be associated with the peculiarities of the mobile loop conformational changes. The presence of sucrose does not provide an advantage in activity but increases the stability of the enzymes. Differential scanning calorimetry experiments showed that luciferases probably follow different denaturation schemes. [ABSTRACT FROM AUTHOR]

Chicken wings are among the most popular poultry products for home and foodservice consumption. Poultry products must be handled and cooked safely to decrease the risk of foodborne salmonellosis for consumers. This study aims to validate the use of domestic appliances (convection and air fryer ovens) for the thermal inactivation of Salmonella on chicken wings. Wings (n = 3, 46.5 ± 4.3 g) were inoculated with a five‐strain cocktail of Salmonella (ca. 8 log10 CFU/wing) and cooked in a convection oven (179.4°C) or an air fryer (176, 190, or 204°C) for 2, 5, 10, 15, 20, 22, or 25 min. Thermocouples recorded temperature profiles of wings and appliances. Salmonella counts were determined on XLD agar for rinsates (100 ml/sample), and rinsates were enriched to recover bacteria below the limit of quantification. The recommended internal cooking temperature (73.8°C) was achieved after a range of 7.5 to 8.5 min in both appliances. Salmonella counts were reduced by 6.5 log10 CFU/wing when this temperature was achieved. Cumulative lethality (F‐value) calculations predicted a 9‐log reduction after 7.0 to 8.1 min of cooking. However, sample enrichments tested positive for Salmonella for all cooking times below 22 min. Ultimately, cooking at the temperature–time combinations recommended by manufacturers and online recipes helped achieve complete microbial elimination in both appliances. This study contributes to the validation of home cooking methods to ensure consumer safety. [ABSTRACT FROM AUTHOR]

To support innovation in the dynamic plant-based foods sector, a study was conducted to set fit for purpose and risk-based alternative thermal processing conditions to the usually used safe harbour heat treatment of 90 °C - 10 min that ensures food safety of extended shelf life refrigerated products. To do so, inactivation data were collected to determine the thermal resistance properties (D- and z-values) of non-proteolytic Clostridium botulinum Type E spores (reference strain NCTC 8266) then build and validate specific inactivation models for two plant-based products: Konjac-based Seafood Analogue (Product 1) and Canola-based Eggs Analogue (Product 2) with desired sensorial properties not compatible with the application of the classical heat treatment of 90 °C - 10 min. D-values were determined at five temperatures ranging from 78 °C to 86 °C for each matrix to build the model and additional data were collected at 75 °C and 80 °C to validate the model. D ref80°C -values were estimated at 1.90 and 0.80 min and z-values at 6.12 °C and 6.84 °C respectively for products 1 and 2. Simulations were performed to estimate the time required to reach the required Performance Objective (PO) of 6 log reductions to ensure food safety at different temperatures for each product. The targeted PO could be reached in both products with lower temperatures and shorter times compared to the safe harbor. Results showed that the inactivation of non-proteolytic C. botulinum Type E spores was faster in product 2 compared to product 1. The developed and validated models, together with the proposed methodology can be used to support food industries in collecting specific data to justify setting fit for purpose heat treatments ensuring food safety with regards to the control of non-proteolytic C. botulinum type E spores without compromising on the desired sensorial properties such as those required for some plant-based products. • Current practice to control non proteolytic Clostridium botulinum in chilled products involves a 90 °C 10 min treatment. • The proposed risk based methodology ensures food safety of chilled foods while safeguarding their sensorial properties. • Linear regression was applied to the log D values obtained at 78 °C to 86 °C to determine the D ref and z parameters for both studied products. • The validated models at 75 °C and 80 °C were used to predict the required times to achieve 6 log reductions. • The developed model and methodology will support the food industry to propose new products and perform fit for purpose risk assessments. [ABSTRACT FROM AUTHOR]

A study was conducted to validate a simulated traditional crust pepperoni pizza baking process to control Shiga toxin-producing Escherichia coli (STEC) and to determine the heat resistance characteristics of STEC in pizza dough. Pizza dough and pepperoni slices were inoculated with 7 strains STEC cocktail and baked at 500°F (260°C) for 12 min using a conventional kitchen oven followed by 15 min of ambient air cooling. The mean internal temperature of the pizza reached 209.32 ± 1.94°F by the end of 12 min of baking and dropped to 137.90 ± 2.88°F after the 15 min ambient air cooling. The aw and pH of the traditional crust pizza did not alter significantly during the baking process. The STEC population decreased by >5 log CFU/g in traditional crust pizza after 12 min of baking. Where pepperoni slices were used as a source of STEC introduction, a reduction of >6.5 log CFU/g was observed. The D-values of STEC cocktail in pizza dough at 55, 58, 61°C were 49.5 ± 4.10, 15.3 ± 0.68, and 2.8 ± 0.31 min, respectively. The z-value of STEC was 4.8 ± 0.16°C. This study validated that a typical traditional crust pizza baking process with ~209°F internal temperature for at least 12 min will result in 5 log reductions in STEC population.