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Conventional farming has significant contribution to India's food production, but its limited effects have become apparent, leading to the need for an alternative agriculture method/technology, which can sustainably operate in a healthy ecosystem while maintaining and increasing quality and productivity. The present study was conducted to elucidate the economic viability of organic vis-a-vis conventional crop production and shows the picture to optimize the resource use efficiency for sustainable crop production in the North Western Himalayas region. The findings showed that organic products had higher output-input ratios for tomato (2.65) and potato (2.56). However, ineffective resource management in terms of over-utilization of organic potato seed and under-utilization of fertilizer, labour and plant protection for organic tomato caused lower productivity. Thus, the optimal level of resource allocation and their effective management are the two basic requirements to minimize costs, and consequently, maximize net income in organic crops. [ABSTRACT FROM AUTHOR]

Postconsumer household food residues can act as useful substrates for other industries, but transporting high‐moisture material corresponds to high fuel use and associated greenhouse gas production. Drying food residues at the household level reduces transportation weight, increases stability, and preserves the nutritional quality of recovered material. Mitigating foodborne microbiological safety risks is crucial to encourage the development of novel methods to rapidly dry and stabilize food residues. The objective of this study was to improve the prediction of bacterial pathogen inactivation under various thermal and drying processes in a synthetic mixture of residual food material (RFM). The log reduction rate was measured for Escherichia coli, Enterococcus faecium, and Listeria innocua (surrogates of common foodborne pathogens) in RFM under different moisture contents (12% and 25% by fresh weight) and temperatures (50, 55, and 60°C). Inactivation data were used to determine D‐ and z‐values and to fit a multiple regression model to predict log(D‐values) in response to temperature and moisture content. Across conditions, D‐values were measured to be 5.1–120, 4.6–123, and 32–545 min for E. coli, L. innocua, and E. faecium, respectively. Temperature sensitivities were significantly higher in lower moisture RFM for E. coli and L. innocua. Applying E. coli inactivation models during RFM at 55°C yielded inactivation rates that aligned with experimental values after 5 min (0.1 vs. 0–0.1 logs), 30 min (2.1 vs. 1.3–2.3 logs), and 90 min (7.2 vs. 7.1–8.9 logs). These results can inform the design of RFM drying and stabilization processes to promote pathogen inactivation and safety in downstream applications of dried material. [ABSTRACT FROM AUTHOR]

Inactivation kinetics of Escherichia coli K12 inoculated in blueberry, grapefruit, cantaloupe, and watermelon juices were evaluated at isothermal temperatures of 52 to 62 °C using thermal death time disks. Juices had variations in titratable acidity, pH, viscosity, and total soluble solids. Survival curves were described by Weibull and linear models, where D‐ and z‐values were determined using the first‐order model. D‐values in watermelon, cantaloupe, blueberry and grapefruit juices, were 6.57–0.64 min, 4.55–0.44 min, 3.94–0.27 min, and 3.03–0.24 min, respectively. The z‐values of E. coli K12 in tested fruit juices ranged from 5.33 to 5.89 °C. While there were no significant differences in the z‐values, the D‐values varied significantly. According to the results obtained, pH and heating temperature dramatically affect the thermal resistance of E. coli K12 under tested conditions. These findings offer a basis for developing predictive models for E. coli inactivation in fruit juices. Practical applications: Thermal death time (TDT) kinetics is extremely useful in ensuring microbial safety of fruit juices. The D‐ and z‐values calculated in this study can contribute to developing predictive models for inactivating E. coli in fruit juices with varied physicochemical attributes. Furthermore, the data and models can be used for optimization of pasteurization processes and regulatory compliance. TDT studies provide the scientific basis for process calculations and help juice manufacturers comply with regulatory requirements. Also, TDT studies help determine the minimal thermal treatments needed to inhibit spoilage organisms, ensuring the juice remains safe and palatable for longer periods. This research will help scientists understand the thermal resistance of E. coli in various fruit juice matrices. [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.

Heat resistance of bacteria is a factor potentially limiting the production of safety foods. We focused on five Enterobacteriaceae strains related to cheese stretching and sub-pasteurisation experimental temperatures of 50-59 °C. Heat resistance was screened and obtained data were fitted to a classical log-linear model with D-values indicating highly heat-resistant strains used. For example in Klebsiella oxytoca S525, D(50)-value was 96.1 min and D(59)-value 5.1 min. In subsequent detailed measurements, the shape of inactivation curves was sigmoid with defined lag, log-linear and stationary phase. We suggest calculating refined D-values (Dr-values) using only data obtained in log-linear phases, namely Dr(temperature; lag phase). In K. oxytoca S525, the obtained results were: Dr(50; 80.9) = 61.7 min, Dr(53; 12.4) = 36.8 min, Dr(56;

Lytic bacteriophages are promising biocontrol agents against pathogenic bacteria for food and therapeutic applications. Investigating the feasibility of combining phage and physical lethal agents, such as heat, as an effective hurdle combination could lead to beneficial applications. The current research was initiated to compare the thermal inactivation kinetics of a lytic phage (Escherichia phage OSYSP) and its host (Shiga toxin-producing Escherichia coli O157:H7 EDL933), considering they have different critical thermal targets in their structures. To provide a basis for comparison, thermal inactivation kinetics were determined on suspensions of these agents in buffered peptone water using a thermally controlled circulating water bath. Results showed that the bacteriophage virions have a remarkable heat resistance (p 0.05) in estimating virus D- and z-values were observed. Based on these findings, it may be feasible to combine phage OSYSP with mild heat during processing of food to selectively inactivate E. coli O157:H7 EDL933 and subsequently maintain product safety during storage by the surviving phage population; however, the feasibility of this application needs to be investigated. Additionally, the relatively heat-resistant phage OSYSP could qualify as a biological indicator to validate thermal treatments of minimally processed foods in which E. coli O157:H7 EDL933 is the pathogen-of-concern.

A yeast, isolated from grape juice concentrate by a grape juice processing company in central Washington, was subjected to thermal processing in 52° Brix grape juice concentrate, commercial grape juice, and Yeast-Mold (YM) medium to determine D-values and z-values in the search for an effective means of control. At 50 ℃ in grape juice concentrate the D-value was 33.44 minutes, dropping rapidly as the temperature increased to 52.5 ℃, 55 ℃, 57.5 ℃, and 60 ℃. From this data, a z-value was determined to be 4.38 ℃. Grape juice and YM broth were similarly tested. Commercial grape juice at 45 ℃, 47 ℃, and 50 ℃ showed D-values of 9.80, 7.68, and 1.42, respectively, resulting in a z-value of 5.69 ℃. The isolate heat treated in YM broth at 40 ℃, 45 ℃, 46 ℃, 47.5 ℃, and 50 ℃ showed no effect at 40 ℃ but at higher temperatures, with a D-value of 2.28 at 45 ℃, 1.61 at 46 ℃, 1.05 at 47.5 ℃, and with a z-value of 7.46 ℃. This data suggests that an increase in the concentration of sugars in the environment has a protective effect on the yeast against elevated temperatures. Even so, pasteurization at 90 ℃ for thirty seconds appears to be an effective means of control for the yeast investigated. A yeast with the identical colony and cell morphology was isolated from 52° Brix grape juice concentrate from the same grape juice processing company. Both isolates were subjected to 28S DNA sequencing and FAME analysis for identification and determined to be Zygosaccharomyces rouxii, a known problem yeast in the grape juice and wine-making industry, to this point unknown in the central Washington region.

Heat resistance of bacteria is a factor potentially limiting the production of safety foods. We focused on five Enterobacteriaceae strains related to cheese stretching and sub-pasteurisation experimental temperatures of 50-59 °C. Heat resistance was screened and obtained data were fitted to a classical log-linear model with D-values indicating highly heat-resistant strains used. For example in Klebsiella oxytoca S525, D(50)-value was 96.1 min and D(59)-value 5.1 min. In subsequent detailed measurements, the shape of inactivation curves was sigmoid with defined lag, log-linear and stationary phase. We suggest calculating refined D-values (Dr-values) using only data obtained in log-linear phases, namely Dr(temperature; lag phase). In K. oxytoca S525, the obtained results were: Dr(50; 80.9) = 61.7 min, Dr(53; 12.4) = 36.8 min, Dr(56; < 10) = 10.6 min, and Dr(59; < 3) = 4.3 min. The research of particular inactivation phases can provide interesting findings both in science and industrial practice, especially concerning the passage or persistence of hazardous strains in food processing plants. [ABSTRACT FROM AUTHOR]

Personalized medicine asks if a new treatment will help a particular patient, rather than if it improves the average response in a population. Without a causal model to distinguish these questions, interpretational mistakes arise. These mistakes are seen in an article by Demidenko [2016] that recommends the "D-value," which is the probability that a randomly chosen person from the new-treatment group has a higher value for the outcome than a randomly chosen person from the control-treatment group. The abstract states "The D-value has a clear interpretation as the proportion of patients who get worse after the treatment" with similar assertions appearing later. We show these statements are incorrect because they require assumptions about the potential outcomes which are neither testable in randomized experiments nor plausible in general. The D-value will not equal the proportion of patients who get worse after treatment if (as expected) those outcomes are correlated. Independence of potential outcomes is unrealistic and eliminates any personalized treatment effects; with dependence, the D-value can even imply treatment is better than control even though most patients are harmed by the treatment. Thus, D-values are misleading for personalized medicine. To prevent misunderstandings, we advise incorporating causal models into basic statistics education.

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

Background: Cronobacter sspecies are the most significant foodborne pathogen in infant milk formula (IMF). These pathogens have been incriminated in severe forms of neonatal meningitis, sepsis, and necrotizing enterocolitis with a high mortality rate. Aim: This study was performed to elucidate the effect of heat stress on Cronobacter spp. (C. sakazakii and C. pulveris) in reconstituted IMF (RIMF). Methods: The reconstituted formula was inoculated with five C. sakazakii isolates and four C. pulveris isolates separately. The nine isolates of Cronobacter spp. were heated in RIMF at 48°C, 52°C, 56°C, 60°C, 64°C, and 66°C. The D- and z-values were determined by using linear regression analysis. Results: The D-values of all isolates of C. sakazakii (CS1, CS3, CS4, CS5, and CS6) at 48°C, 52°C, 56°C, 60°C, 64°C, and 66°C were in the ranges 7.29-23.47, 2.77-15.50, 0.62-1.04, 0.62-1.02, 0.62-1.00, 0.62-1.00 minutes, respectively; while, the z-values extended from 2.50°C to 4.28°C. The D- values of C. pulveris isolates (CP1, CP2, CP3, CP4) were in the ranges 7.60-22.32, 1.42-8.45, 0.62-1.08, 0.62-0.78, 0.62-0.78, 0.62-0.79 minutes at 48°C, 52°C, 56°C, 60°C, 64°C, 66°C, respectively and the calculated z-values ranged from 3.33°C to 4.89°C. Conclusion: This study may contribute to improving the understanding of the behavior of C. sakazakii and C. pulveris isolates in RIMF at various heat stress temperatures and may participate in the effective control of these pathogens in infant food production. [ABSTRACT FROM AUTHOR]

The present investigation assesses the influence of cultural attributes and heat and cold treatments on the behaviour of native toxigenic L. monocytogenes CFR 1302 and non-toxigenic L. innocua CFR 1304 in selected medium. The growth responses of L. monocytogenes and L. innocua under the influencing factors of storage temperature (10-40°C), pH level (5.5-7.5), and storage period (6-48 h) in brain heart infusion and nutrient broths revealed closeness between observed and predicted populations. Response surface plots were generated for the growth behavior of the two test cultures as a function of pH level. The toxigenic L. monocytogenes CFR 1302 could reach a higher viable population. The effect of heat treatment on Listeria spp. in selected five heating menstra showed the lowest D-value of 3.7 min at 60°C for L. innocua CFR 1304 in Milli-Q water to the highest of 8.4 min at 56°C for L. monocytogenes CFR 1302 in skim milk. The average z-value across the heating menstra for L. monocytogenes was 27.3°C as against that of 22°C for L. innocua. In the case of cold treatment, storage of 4 and 8°C resulted in appreciable increase in counts of L. monocytogenes CFR 1302 from the initial inoculum introduced in selected media. At -20°C, there was a slight decrease in the viable population. The research data helps to predict the viable populations of L. monocytogenes as a part of risk assessment in the food chain. This is of significance in providing safe and healthy food to human population.

This study investigated the heat resistance of Bacillus cereus spores (as well as spores in intact biofilm) in two types of Korean fermented soybean foods and presumed the potential key parameters (physicochemical and nutritional properties) associated with their heat resistance. For example, the D 100°C -values of B. cereus ATCC 10987 and CH3 spores with strong heat resistance and prolific biofilm-forming capability were compared in various Jjigae -type (Cheonggukjang jjigae , Doenjang jjigae , and Gochujang jjigae) and Jang -type (Cheonggukjang , Doenjang , and Gochujang) foods commonly consumed in Korea. The D 100°C -values of planktonic spores were significantly different depending on the type of food, that is, Jang and Jjigae. Compared with Jjigae -type foods, a higher heat resistance of B. cereus spores was found in Jang -type foods (particularly Doenjang and Gochujang) with low water activity and high salinity. In Jjigae -type foods, spore heat resistance showed a positive correlation with the pH of Jjigaes , indicating that an acidic environment weakens the spores. A negative correlation between the total fat content and spore heat resistance was found in Jjigae -type foods but not in Jang -type foods. Meanwhile, regarding the heat resistance of B. cereus spores in intact biofilm, the D 100°C -values were significantly higher (up to 6.5-fold) than those of planktonic spores in all Jjigae -type foods. The slightly acidic pH and amount of carbohydrates are likely related to the large formation of extracellular polymeric substances and strong heat resistance of B. cereus spores in biofilm. This study may provide a comprehensive understanding of the relationship between the key parameters of foods and heat resistance of B. cereus spores with or without intact biofilm and methods to control their risks in different types of fermented soybean foods. • The D -value of B. cereus spores varied depending on the soybean food type/variety. • The D -value of spores was higher in Jang with lower water activity than in Jjigae. • In Jjigae , pH and total fat content had opposite effects on the D -value of spores. • Biofilm formation varied significantly depending on the Jjigae variety. • Biofilm formation significantly increased the heat resistance of spores in Jjigae. [ABSTRACT FROM AUTHOR]

The objective of this study was to identify a suitable surrogate for E. coli O157:H7 strain 19685/91 and O113:H21 strain TS18/08, by assessing their thermal resistance at temperatures of 60 °C, 65 °C, and 72 °C in strawberry nectar. The influence of the matrix and the research methodology on the decimal reduction time (D-value) was investigated. Thermal kinetics and safety assessment demonstrated that E. coli ATCC 8739 is a suitable surrogate. The study demonstrated that the presence of fruit particles in the nectar increased thermal resistance of the tested strains. Variations in D-values were observed depending on the research method employed, with D-values in glass capillaries were up to 6.6 times lower compared to larger sample volumes. Encapsulation of E. coli ATCC 8739 exhibited high efficiency of 90.25 ± 0.26% and maintained stable viable counts after 26 days of storage in strawberry nectar at 4 °C. There were no significant differences in thermal resistance between surrogates directly inoculated into strawberry nectar and those encapsulated in alginate beads. Additionally, the encapsulated strains did not migrate outside the beads. Therefore, encapsulated E. coli ATCC 8739 in alginate beads can be effectively utilized in industrial settings to validate thermal treatments as a reliable and safe method. • E. coli ATCC 8739 is a suitable surrogate for selected EHEC strains. • Bacteria encapsulation is an effective and safe method of validating heat treatment. • The thermal resistance testing method influences the obtained results. • Dry mass of nectar influences the thermal resistance of inoculated bacteria. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Hummus is a popular dip in the Middle East region prepared by mixing the boiled chickpeas with tahini and other ingredients, and because its consumption has increased world‐wide some notoriety has developed following an increase in the incidence of hummus‐related illness outbreaks and recalls. The objectives of the current research were (i) to study the efficiency of low dose gamma irradiation to inhibit Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes in hummus, and (ii) to assess the effect of environmental stresses namely cold, heat, and desiccation on the resistance of these pathogens to gamma irradiation. The samples of hummus were prepared and then individually inoculated with approximately 7.0 log CFU/g of unstressed or cold‐, heat‐, or desiccated‐stressed cocktail cultures of each of E. coli O157:H7, S. enterica, and L. monocytogenes. The inoculated samples were then exposed to gamma irradiation at doses of 0.1 to 0.6 kGy. The numbers of unstressed E. coli O157:H7, S. enterica, and L. monocytogenes were decreased by 0.6–3.9, 0.7–2.9, and 1.0–3.0 log CFU/g, respectively, by irradiation treatment. The resistance of E. coli O157:H7 to gamma irradiation was not affected by desiccation, heat, and cold stresses. However, the pre‐exposure of S. enterica and L. monocytogenes cells to these stresses reduced their resistance toward gamma irradiation. Practical Application: Gamma irradiation is a non‐thermal treatment that can be used in food processing to ensure food safety and quality. The current study proved that low levels (≤0.6 kGy) of gamma irradiation can effectively decrease the risk of unstressed and cold‐, heat‐, or desiccation‐stressed Salmonella enterica, Listeria monocytogenes, or Escherichia coli O157:H7 in hummus. [ABSTRACT FROM AUTHOR]

Response surface methodology (RSM) refers to experimental designs for optimizing or developing processes, initially in manufacturing. In this paper, a new method is presented and an algorithm is implemented that modifies the axial part in a central composite design to achieve a good D-value and efficiency. The new designs are suitable for sequential experimentation. In comparison with known designs in the same class, the new designs are tested and found to have better D-values on a range of factors. With this new approach, efficient orthogonal designs for response surface methodology were generated for a number of parameters that were previously impossible to construct. The new generated designs and their comparison with known designs from the literature are presented in tables for practitioners’ use.

The present investigation assesses the influence of cultural attributes and heat and cold treatments on the behavior of native toxigenic L. monocytogenes CFR 1302 and non-toxigenic L. innocua CFR 1304 in selected medium. The growth responses of L. monocytogenes and L. innocua under the influencing factors of storage temperature (10-40°C), pH level (5.5-7.5), and storage period (6-48 h) in brain heart infusion and nutrient broths revealed closeness between observed and predicted populations. Response surface plots were generated for the growth behavior of the two test cultures as a function of pH level. The toxigenic L. monocytogenes CFR 1302 could reach a higher viable population. The effect of heat treatment on Listeria spp. in selected five heating menstra showed the lowest D-value of 3.7 min at 60°C for L. innocua CFR 1304 in Milli-Q water to the highest of 8.4 min at 56°C for L. monocytogenes CFR 1302 in skim milk. The average z-value across the heating menstra for L. monocytogenes was 27.3°C as against that of 22°C for L. innocua. In the case of cold treatment, storage of 4 and 8°C resulted in appreciable increase in counts of L. monocytogenes CFR 1302 from the initial inoculum introduced in selected media. At -20°C, there was a slight decrease in the viable population. The research data helps to predict the viable populations of L. monocytogenes as a part of risk assessment in the food chain. This is of significance in providing safe and healthy food to human population. [ABSTRACT FROM AUTHOR]

Aichi virus (AiV) that results in gastroenteritis worldwide, is spread through contaminated shellfish and water. The resistance/tolerance of AiV to common inactivation processes along with the absence of commercially available vaccines makes it necessary to study its thermal inactivation kinetics. This research evaluated the heat inactivation of AiV in cell‐culture media using 2‐ml sterile glass vials by the linear and Weibull models. Heat treatments of AiV titers of 7 log plaque forming units (PFU)/ml were conducted thrice in a water‐bath at 50, 54, and 58 °C for up to 90 min. Plaque assays for each dilution in duplicate were used to determine infectious virus titers. Linear model D‐values for AiV at 50 ± 1 °C (± = standard error) (come‐up time = 68 s), 54 ± 0.7 °C (130 s), and 58 ± 0.6°C (251 s) were 43.3 ± 4.23 (R2 = 0.40, RMSE = 0.56), 5.69 ± 0.28 (R2 = 0.80, RMSE = 0.43), and 1.20 ± 0.63 min (R2 = 0.69, RMSE = 0.39), respectively, and the linear model z‐value was 5.14 ± 0.39°C (R2 = 0.99, RMSE = 0.08). For the same temperatures, the Weibull model td = 1 values were 20.98 ± 8.8 (R2 = 0.62, RMSE = 0.46, α (scale parameter) = 2.30, β (shape parameter) = 0.38), 3.84 ± 0.69 (R2 = 0.85, RMSE = 0.38, α = 1.08, β = 0.66), and 0.87 ± 0.10 min (R2 = 0.80, RMSE = 0.32, α = 0.22, β = 0.61), respectively and the z‐value (using Td = 1) was 5.79 ± 0.22 °C (R2 = 1.0, RMSE = 0.03). A better fit was obtained with the Weibull model for log reductions versus time with higher R2 and lower RMSE values. Application of AiV inactivation parameters can help reduce the risk of AiV outbreaks. [ABSTRACT FROM AUTHOR]

Intervention technologies for inactivating Salmonella on whole chia seeds are currently limited. Determination of the thermal inactivation kinetics of Salmonella on chia seeds and selection of an appropriate nonpathogenic surrogate will provide a foundation for selecting and optimizing thermal pasteurization processes for chia seeds. In this study, chia seed samples from three separate production lots were inoculated with a five-strain Salmonella cocktail or Enterococcus faecium NRRL-B2354 and equilibrated to a water activity of 0.53 at room temperature (25°C). After equilibration for at least 3 days, the inoculated seeds were subjected to isothermal treatments at 80, 85, or 90°C. Samples were removed at six time points, and surviving bacteria were enumerated. Whole chia seeds were diluted in a filter bag at 1:30 because bacterial recovery with this method was similar to that obtained from ground seeds. Survivor data were fitted to consolidated models: one primary model (log linear or Weibull) and one secondary model (Bigelow). E. faecium had higher thermal resistance than did Salmonella, suggesting that E. faecium may be a suitable conservative nonpathogenic surrogate for Salmonella. The Weibull model was a better fit for the survivor data than was the log-linear model for both bacteria based on the lower root mean square error and corrected Akaike's information criterion values. Lipid oxidation measurements and fatty acid concentrations were significantly different from those of the control samples, but the overall magnitude of the differences was relatively small. The thermal inactivation kinetics of Salmonella and E. faecium on chia seeds may be used as a basis for developing thermal pasteurization processes for chia seeds. [ABSTRACT FROM AUTHOR]

Heat resistance, D- and z-values of five Salmonella enterica strains, namely S. Senftenberg LTH 5703, S. Typhimurium ATCC 13311 and ATCC 14028, S. Saintpaul LTH 6494, and S. Enteritidis ATCC 13076, as well as of a Salmonella cocktail and three potential surrogate strains were investigated in phosphate buffered saline and strawberry nectar (12° Brix). Thermal inactivation was performed at 60 °C, 65 °C, and 72 °C. Moreover, the influence of pre-incubation under stressful environmental conditions on the heat resistance was tested. The results identified Escherichia coli ATCC 11229 as a suitable surrogate candidate for Salmonella strains, as its calculated D-values in both matrices were higher or statistically the same than those of the examined pathogens. The safety analysis showed no virulence factors that could classify E. coli ATCC 11229 as a pathogen. Furthermore, the results show significant differences in D-values of all strains in different matrices, which indicates a clear influence of the environment on heat resistance of bacteria. The pre-incubation under stress conditions had no significant effect on the heat resistance of E. coli ATCC 11229. However, further research is needed to explore the influence of stress conditions and duration on bacterial heat resistance. • E. coli ATCC 11229 is a suitable surrogate for selected Salmonella strains. • Thermal resistance of Salmonella cocktail corresponds to that of individual strains. • Bacterial heat resistance differs in strawberry nectar and neutral environment. • Pre-incubation of E. coli ATCC 11229 under stress does not induce cross-protection. [ABSTRACT FROM AUTHOR]

In this study, we investigated the effect of food matrices on the heat tolerance of Salmonella strains and evaluated the impact of sugar and fat on the heat resistance of these strains. We tested ten strains of Salmonella spp. isolated from eggs and ten from sesame seeds. The conducted research revealed that S. Poona 4193 and S. Oranienburg 4182, isolated from sesame seeds, exhibited the lowest average decimal reduction times (D-values) at 60 °C and 65 °C. Conversely, strains of S. Enteritidis 3927 (eggs), and S. Mbandaka 4297 (sesame seeds), demonstrated the highest D-values. In the next stage we examined the effect of different concentrations of sucrose (5%, 10%, 15%) and sesame oil (10%, 25%, 50%) on the tolerance of Salmonella to high temperatures. We then selected specific concentrations of sucrose and oil in the medium for each strain based on the highest D-value obtained. The 4297 strain exhibited the highest D-value with 5% sucrose and 10% oil, 4193 strains with 10% sucrose and 25% oil, 4182 with 10% sucrose and 10% oil, and 3927 strain with 10% sucrose, and 50% oil. Our studies indicated that the heat resistance of Salmon ella is highly dependent on the specific strain. • Salmonella strains isolated from eggs and sesame seeds showed varying thermal tolerance. • Thermal tolerance is a trait of the strain. • The impact of concentrations of sucrose and oil on the temperature resistance of Salmonella strains wasn't inconclusive. [ABSTRACT FROM AUTHOR]

A previous investigation from our research group has revealed that lemon balm and spearmint hydroethanolic extracts present high inhibitory capacity in vitro against S. aureus. Raw milk cheeses have exhibited moderate prevalence of S. aureus, thus imposing a safety issue for consumers. In this sense, our work aimed to evaluate the antibacterial effect of lemon balm and spearmint extracts against S. aureus in goat’s raw milk cheeses during maturation, and to characterise the survival kinetic parameters of this pathogen by extended Bigelow models.

The extraction, purification, and characterization of PME and PG were studied for lemon fruit. Enzymes were partially purified by anion-exchange chromatography using UNOsphere™ Q anion exchanger for lemon PME and DEAE Cellulose anion exchanger for lemon PG. A single band with a fold purity of 20.95 and 15.75 for PME and PG respectively was observed on SDS-PAGE. Molecular weights of partially purified fractions of PME and PG as exhibited by SDS-PAGE were 48 kDa and 95 kDa respectively. Optimum pH and temperature of partially purified lemon PME and PG were pH 9, pH 5 and 45 °C. The crude PME and PG extracts exhibited D-values of 120.57–63.79 and 185.72–29.18 min; Z-values of 15.11 and 16.50 °C; and activation energies (Ea) of 58.23 and 57.18 kJ/mol, respectively. The enzyme stability was not significantly influenced by the fruit matrix as reflected by Z and Ea values. D and Z-values of both the enzymes and microorganisms should be considered while designing thermal treatments to obtain a product with better shelf life. [ABSTRACT FROM AUTHOR]

The Himalayan belt is known for seismic activities; however, activities across this belt are not uniform due to various factors, including stress regime, heterogeneity of subsurface material, and the manner by which the major tectonic Indian plate is colliding with the Eurasian plate. In this study, three sample regions spanning northwest to northeast Himalayas (Kashmir, Nepal, and northeast Himalayan regions) were selected, and their b-values and fractal dimensions from the investigation period of 1973–2015 were calculated. Subsequently, the b-value was calculated via the Gutenberg–Richter relation and maximum likelihood method, whereas the fractal dimension or D-value was calculated using the correlation integral technique. Upon subdividing the time duration into six equal interval subsets, a variation in b-value can be observed over the years. The period 1973–2015 was selected to ensure the sufficiency of data in each subset and an adequate number of subsets for comparisons. From the low b-values, possible high-stress regions and asperities can be inferred, and the variation in stress and heterogeneity of material can be observed from the northwest to northeast Himalayas. An increase in b-value was observed on moving from the northwest to northeast Himalayas during the period of investigation. From the D-value, the extent of the epicentre cluster was observed, revealing that the epicentres were far more clustered to a point in Nepal Himalayas than in the two other regions. The spatial distribution of epicentres was more or less in 1D (fractal dimension) in the northeast and northwest Himalayas, indicating their distribution along particular geological linear features, such as major faults. Hence, a comparative study of the three regions was achieved. On the basis of the b-value, the types of fault and tectonics can be predicted, and the frequency of earthquakes in these Himalayan regions can be better understood. [ABSTRACT FROM AUTHOR]

Thermal stability (D -value and pasteurization) and gastric acid resistance of spore forming and nonspore forming probiotic strains were evaluated in this study. Bacillus coagulans MTCC 5856 spores showed highest thermal resistance (D -value 35.71 at 90 °C) when compared with other Bacillus strains and Lactobacillus species. B. coagulans strains exhibited significantly higher resistance to simulated gastric juice (pH 1.3, 1.5, and 2.0) compared to Lactobacillus strains. It also showed high resistance to cooking conditions of chapati (whole wheat flour-based flatbread) (88.94% viability) and wheat noodles (and 94.56% viability), suggesting remarkable thermal resistance during food processing. Furthermore, B. coagulans MTCC 5856 retained 73% viability after microwave cooking conditions (300 s, at 260 °C) and 98.52% in milk and juice at pasteurization temperature (420 min, at 72 °C). Thus, B. coagulans MTCC 5856 clearly demonstrated excellent resistance to gastric acid and high temperature (90 °C), thereby suggesting its extended application in functional foods (milk, fruit juices, chapati, and wheat noodles) wherein high temperature processing is involved. [ABSTRACT FROM AUTHOR]

The presence of Listeria monocytogenes in Mozzarella di Bufala Campana Protected Designation of Origin cheeses may depend on curd stretching conditions and post contaminations before packaging. To avoid cross-contamination, thermal treatment of water, brines and covering liquid may become necessary. The present study aimed to improve knowledge about L. monocytogenes thermal resistance focusing on the influence of some cheese making operations, namely curd stretching and heat treatment of fluids in contact with cheese after molding, in order to improve the safety of the cheese, optimize efficacy and sustainability of the processes. Moreover, the role that cheese curd stretching plays in L. monocytogenes inactivation was discussed. The 12 tested strains showed a very heterogeneous heat resistance that ranged from 7 to less than 1 Log10 Cfu/mL reduction after 8 min at 60°C. D-values (decimal reduction times) and z-values (thermal resistance constant) calculated for the most heat resistant strain among 60 and 70°C were highly affected by the matrix and, in particular, heat resistance noticeably increased in drained cheese curd. As cheese curd stretching is not an isothermal process, to simulate the overall lethal effect of an industrial process a secondary model was built. The lethal effect of the process was estimated around 4 Log10 reductions. The data provided may be useful for fresh pasta filata cheese producers in determining appropriate processing durations and temperatures for producing safe cheeses.

Egg powders are increasingly popular ingredients, due to their functionality and compactness, in industrial food production and preparation at homes. However, there is a lack of studies that evaluate the thermal resistance of Salmonella Enteritidis PT30 and its potential surrogate Enterococcus faecium NRRL B-2354 in egg powders. This study examined the log-linear relationship between the thermal resistance of Salmonella Enteritidis (D-value) and the water activity (aw) of egg powders. The changes of aw in the egg powders with temperature were measured using a Vapor Sorption Analyzer and a high-temperature cell. The D80 ℃-value of S. Enteritidis PT30 and E. faecium inoculated in the egg powders preconditioned to three aw levels (0.3, 0.45, and 0.6) at 20 ℃ were determined using aluminum thermal death test cells. The aw values increased (P < 0.05) in all three egg powders when the temperature of the samples was raised from room temperature to 80 ℃. The D80 ℃-values ranged from 5.3 ± 0.1 to 25.9 ± 0.2 min for S. Enteritidis while 10.4 ± 0.4 to 43.8 ± 0.4 for E. faecium in samples of the three different aw levels. S. Enteritidis PT30 showed a log-linear relationship between D80 ℃-values and aw80 ℃ for the egg powders. This study contributes to our understanding of the impact of aw on the development of thermal treatments for low-moisture foods. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus is a significant opportunistic pathogen in humans, dairy cattle, and camels. The presence of antibiotic-resistant and heat-resistant bacteria in camel milk has become a potential public health issue. The phenotypic and molecular characterization of methicillin-resistant staphylococcal strains recovered from pasteurized camel milk distributed in retail markets of Saudi Arabia was assessed. A total of 100 samples were collected between March and May 2017. Out of the 20 S. aureus isolates that were recovered from the pasteurized camel milk, 10 were found to be resistant to cefoxitin (30 µg) and, thus, were designated as methicillin-resistant strains. The resistance ratio of methicillin-resistant S. aureus isolates for a different class of antibiotics was determined by performing the antimicrobial susceptibility test and was estimated to be approximately 60%. Polymerase chain reaction assay was performed to amplify the methicillin-resistant gene mecA , and furthermore, nucleotide sequencing was performed to detect and verify the presence of methicillin-resistant strains. Upon sequencing the putative S. aureus methicillin-resistant strains, we obtained 96 to 100% similarity to the penicillin-binding protein 2a gene (mecA) of the S. aureus strain CS100. Moreover, the 10 methicillin-resistant S. aureus isolates were also identified to be heat resistant and were stable at temperatures up to 85°C for 60 s, with 3 isolates being heat resistant even at 90°C for 60 or 90 s. The mean decimal reduction time (D 85 value) was 111 s for all the 10 isolates. No difference was observed in the profile of total protein between the 10 methicillin- and heat-resistant S. aureus isolates and the S. aureus strain ATCC 29737, which was determined by sodium dodecyl sulfate-PAGE analyses. Therefore, we could conclude that a relatively high percentage of the tested pasteurized camel milk samples were contaminated with S. aureus (20%) and methicillin- and heat-resistant S. aureus (10%). [ABSTRACT FROM AUTHOR]

Decontamination practices which often involve thermal treatments are routinely performed in beef packing plants and have generally improved the safety of meat in North America. We investigated whether Escherichia coli in the beef production chain are becoming more heat resistant due to those treatments. Cattle isolates (n = 750) included seven serogroups (O157, O103, O111, O121, O145, O26 and O45) which were collected between 2002 and 2017. Beef plant isolates (n = 700) from carcasses, fabrication equipment, and beef products were included. Heat resistance was determined in Luria-Bertani broth at 60o C, and by PCR screening for the locus of heat resistance (LHR). The decimal reduction for E. coli at 60o C (D60°C-values) ranged from 0 to 7.54 min, with 97.2% of the values being < 2 min. Prevalence of E. coli with D60°C32 values > 2 min was not significantly different (P > 0.05) among cattle and meat plant isolates. E. coli from equipment before sanitation (median, 1.03 min) were more heat resistant than those after sanitation (median, 0.9 min). No significant difference in D60°C-values was observed between E. coli from different years, carcasses before and after antimicrobial interventions, or before and during carcass chilling. Of all isolates, 1.97% harbored LHR, and the LHR positive isolates had greater median D60°C-value than the LHR negative ones (3.25 vs 0.96 min). No increase in heat resistance in E. coli was observed along the beef production chain or with time. Importance. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the decimal reduction times (D) and the thermal resistance parameter (z) values of relevant foodborne pathogens linked with fruit juice consumption - namely Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes. Cocktails of different strains of the same bacterial species were prepared and thereafter subjected to thermal inactivation studies at 50, 53, 55, 57, and 60 °C heating temperatures in orange juice. Survivor populations were determined by surface-plating onto a non-selective medium, after which the inactivation behavior and kinetic parameters were determined. Results showed that for all tested organisms, the D-values significantly (P < 0.05) decreased with increasing heating temperature. In all heating temperatures, E. coli O157:H7 exhibited the significantly greatest heat resistance, with D-values ranging from 324.60 s to 95.12 s. At 50 °C, L. monocytogenes (D-values 152.32 s to 11.84 s) was significantly more resistant than S. enterica (D-values 106.55 s to 19.29 s). At higher heating temperatures, the D-values of S. enterica and L. monocytogenes were not significantly different (P > 0.05). The calculated z-values significantly varied across the test organisms, which ranged from 9.40 °C (L. monocytogenes) to 18.78 °C (E. coli O157:H7). These results may be used in the establishment of new, and validation of existing, thermal process schedules to ensure safety against the test pathogens. [ABSTRACT FROM AUTHOR]

The objective of the present study was to evaluate the effect of boiling duration on physicochemical, bioactive compounds, antioxidant activity, color, and texture properties of pumpkin (Cucurbita maxima). The pumpkin was subjected to boiling for 1, 5, 10, and 20 min at 100 ℃. The physicochemical analyses showed that pH, moisture, and water solubility index were increased, whereas ash content was decreased with increasing the boiling time. Prolong boiling exhibited a detrimental effect on bioactive compounds of pumpkin, and it was found that 20 min of boiling caused about 25.91% ± 2.21% loss of total phenolic content, 14.79% ± 1.03% loss of total carotenoids content, and 18.46% ± 1.34% loss of antioxidant activity. A kinetic study was conducted to quantify the losses occurring in bioactive compounds, antioxidant activity, changes in color, and firmness of pumpkin. The study revealed that the logistic model can predict the variation in bioactive compounds and antioxidant activity with higher R2. However, first-order kinetic models were found suitable to predict the changes occurring in bioactive compounds, antioxidant activity, color properties (L*, a*, b*, Chroma), and firmness. The total color changes (ΔE) showed a good fit with zero-order kinetic models (R2 = 0.98). The t1/2 and D-value were calculated for all measured parameters of pumpkin. These findings would be useful in designing thermal processes and related calculations of pumpkin. [ABSTRACT FROM AUTHOR]

Ohmic heating (OH) is a novel method of heating various food materials efficiently, instantly and volumetrically. The quick and volumetric heating during OH results in efficient enzyme and microbial inactivation. Thus, OH can be used as an efficient alternative to the conventional thermal processing method. OH has been applied to various food materials, which include fruits and vegetable products, milk, meat, seafood etc. Inactivation of quality degrading enzymes and spoilage causing microbes to a desired safe level is the prime objective of thermal processing of food, which can be easily achieved by OH process. In addition to the thermal effects, OH also has some non-thermal effects on microbial and enzyme activities due to the presence of electric current during heating. However, these non-thermal effects of OH are possible only in enzymes containing prosthetic metallic groups such as, Cu in PPO, Fe in lipoxygenase, Zn and Mg in alkaline phosphatase. Various models such as First order, Bi-phasic and Lumry–Eyring mechanism have been reported in literature for the enzyme inactivation by OH. Enzyme inactivation has been found to increase with increasing electric field strength (V/cm) during the OH process. The spoilage causing microorganisms can also be inactivated efficiently by OH as compared to conventional heating. Higher voltage gradients enhance the non-thermal effects of OH on microbial reduction by resulting in the higher electroporation. The frequency of the electric current also plays an important role in microbial reduction. Various components present in food such as fat, sugar and acid content affect the electrochemical properties of food material, thus affect the performance of OH in reducing the microbial load. • Enzyme and microbial inactivation during conventional and OH have been compared. • Non thermal effects of OH on the enzymes and microbial activity have been explained. • Effects of composition and ingredients on enzyme and microbial inactivation during OH. • Electroporation due to OH causes higher microbial cell damage than thermal treatment. [ABSTRACT FROM AUTHOR]

Tahini (sesame paste) is a traditional food. Numerous foodborne outbreaks have been associated with it. This study aimed to (i) explore the efficiency of 2450 MHz microwave heating at 220, 330, 440, 550, and 660 W on the inactivation of Salmonella spp, Escherichia coli O157:H7, and Listeria monocytogenes in tahini; (ii) determine the impact of desiccation and starvation stresses on pathogen survival; (iii) assess the impact of microwave heating on the physicochemical characteristics of tahini. The inoculated microorganisms in tahini were reduced with higher microwave power levels (p < 0.05) and longer exposure times. The D-values of unstressed Salmonella spp., Escherichia coli O157:H7, and L. monocytogenes ranged from 6.18 to 0.50 min, 6.08 to 0.50 min, and 4.69 to 0.48 min, respectively, at power levels of 220 to 660 W, with z-values of 410, 440, and 460 W, respectively. Generally, desiccation and starvation stress levels prior to heating increased microbial resistance to heat treatment. Microwave heating did not affect acid, peroxide, p-anisidine, or color values of tahini up to 90 °C. These findings reveal microwave heating as a potential method for lowering the risk of Salmonella spp., E. coli O157:H7 and L. monocytogenes in tahini with no compromise on quality.

Lytic bacteriophages are promising biocontrol agents against pathogenic bacteria for food and therapeutic applications. Investigating the feasibility of combining phage and physical lethal agents, such as heat, as an effective hurdle combination could lead to beneficial applications. The current research was initiated to compare the thermal inactivation kinetics of a lytic phage (Escherichia phage OSYSP) and its host (Shiga toxin-producing Escherichia coli O157:H7 EDL933), considering they have different critical thermal targets in their structures. To provide a basis for comparison, thermal inactivation kinetics were determined on suspensions of these agents in buffered peptone water using a thermally controlled circulating water bath. Results showed that the bacteriophage virions have a remarkable heat resistance (p < 0.05) compared to their host cells. The D-values of the populations of phage (PFU/mL) and EDL933 strain (CFU/mL) were 166.7 and 7.3 min at 55°C, compared to 44.4 and 0.3 min at 60°C, respectively. Additionally, D-values were significantly (p < 0.05) more influenced by temperature changes in the case of E. coli O157:H7 EDL933 (z-value 3.7°C) compared to that for phage OSYSP (z-value 7.7°C). When the phage suspension was heat-treated in a thermal cycler instead of a water bath, no significant differences between the two treatment procedures (p > 0.05) in estimating virus D- and z-values were observed. Based on these findings, it may be feasible to combine phage OSYSP with mild heat during processing of food to selectively inactivate E. coli O157:H7 EDL933 and subsequently maintain product safety during storage by the surviving phage population; however, the feasibility of this application needs to be investigated. Additionally, the relatively heat-resistant phage OSYSP could qualify as a biological indicator to validate thermal treatments of minimally processed foods in which E. coli O157:H7 EDL933 is the pathogen-of-concern., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

The purpose of this work was to determine the effect of previously designed test cell thickness and environmental heating temperature on the accuracy of estimated D- and z- values in low-moisture foods. The D- and z-values of Clostridium sporogenes were determined isothermally by 1-step and 2-step regression methods. The more accurate D- and z-values were obtained by 1-step regression compared with 2-step regression. The non-isothermal and 1-step estimation method was applied to determine the microbial inactivation parameters of Clostridium sporogenes. The D- and z-values estimated by that method had the same level of accuracy as those from the isothermal and 1-step method. The novel non-isothermal and 1-step estimation method of D- and z-values had the advantage of reduced experimental effort. Using literature values of D, z and thermophysical properties, and the exact solution for transient heat conductions, the optimum design of test cell for determination of D and z-vales of Clostridium sporogenes and Salmonella in low-moisture food was presented. • Design criteria were presented for a test cell used to estimate microbial inactivation parameters in low-moisture foods. • 1 step regression for determination of D- and z-values was compared with 2-step. • D- and z-values were more accurately estimated by 1-step regression. • The Non-isothermal method has the advantage of reduced experimental effort. • Design factors of the test cell for inactivation kinetic studies were given. [ABSTRACT FROM AUTHOR]

Accurate prediction of the thermal destruction rate of foodborne pathogens is important for food processors to ensure proper food safety. When bacteria are subjected to thermal stress during storage, sublethal stresses and/or thermal acclimation may lead to differences in their subsequent tolerance to thermal treatment. The aim of the current study was to evaluate the thermal tolerance of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica, and Staphylococcus aureus that are incubated during overnight growth in tryptic soy broth at four temperatures (15, 25, 35, and 45°C). Following incubation, the bacteria were subjected to thermal treatments at 55, 60, and 65°C. At the end of each treatment time, bacterial survival was quantified and further calculated for the thermal death decimal reduction time (D‐value) and thermal destruction temperature (z‐value) using a linear model for thermal treatment time (min) vs. microbial population (Log CFU/ml) and thermal treatment temperature (°C) vs. D‐value, respectively, for each bacterium. Among the four bacterial species, E. coli generally had longer D‐values and lower z‐values than did other bacteria. Increasing patterns of D‐ and z‐values in Listeria were obtained with the increment of incubation temperatures from 15 to 45°C. The z‐values of Staphylococcus (6.19°C), Salmonella (6.73°C), Listeria (7.10°C), and Listeria (7.26°C) were the highest at 15, 25, 35, and 45°C, respectively. Although further research is needed to validate the findings on food matrix, findings in this study clearly affirm that adaptation of bacteria to certain stresses may reduce the effectiveness of preservation hurdles applied during later stages of food processing and storage. [ABSTRACT FROM AUTHOR]

Determination of the in vitro properties of 6 herbal extracts and 4 probiotic bacteria was performed to examine their potential for being used as a co- functional product. The antioxidant and anti- inflammatory activities of the re- soluble extracts of Cordycep sinensis, Garnoderma lucidum, Tagetes erecta, Terminalia chebula Retz., T. bellirica Roxb., and Phyllanthus emblica were investigated. P. emblica and T. chebula possessed the top 2 highest DPPH radical scavenging activities of 94.07% and 88.75%, respectively. For antiinflammation, the highest percentage was found in T. bellirica (12.11%). There was no antibacterial effect of those herbal solutions on 4 probiotic bacteria, i. e. Bifidobacterium longum BCC 51139, Pediococcus acidilactici TISTR 2309, Lactobacillus acidophilus TISTR 2365, and Lactobacillus casei TISTR 1463. For in vitro cholesterol reduction, B. longum and L. casei were the strains with the most potential (87.68% and 85.71% decline, respectively). Model capsules of a mixture of herbal powder (Triphala herbs including T. chebula, T. bellirica, and P. emblica) and each freeze-dried probiotic were prepared. The acid tolerance test showed that the cell numbers of all 4 bacteria in the model capsules decreased only 0.5 log CFU/g at pH 2.0 when compared to those at pH 6. 4, whilst L. acidophilus was sensitive to bile salt (> 5 log reduction). The decimal reduction time was exploited to evaluate the storage life of the capsules at room temperature. The D-values of L. acidophilus and P. acidilactici were 46 and 25 days, respectively, whereas L. casei and B. longum had 15 days of D-value. [ABSTRACT FROM AUTHOR]

Salmonella enterica is a major cause of foodborne pathogen contamination in the United States. The heat resistance of Salmonella increases as a w decreases, leading to a significant challenge in the design of thermal processes. The aluminum thermal death time (TDT) cell is a common experimental tool to study the isothermal resistance of Salmonella and other pathogenic bacteria in foods. However, the TDT cell has the problem of a relatively long come-up time, and it is difficult to seal. This research improved the previous design of aluminum TDT cells and evaluated the performance of the improved design by using the thermal inactivation data of Salmonella enterica cocktail and Enterococcus faecium in brown rice flour. The come-up time of brown rice flour was reduced significantly, from 2.33 min in the previous design to 0.67 min (40 s) in the improved design of test cells when immersed in an 85 °C glycol bath. With the increase of the cavity diameter of the cell, it was easy to load and unload food samples. Additional new features of the improved design included the wrench flats on the outer surface of cell wall. The D -values for Salmonella in the a w 0.45 (measured at 25 °C) brown rice flour were 42.70, 17.51, 8.11, and 2.27 min at 70, 75, 80, and 85 °C, respectively. The D -values for Enterococcus faecium were 65.82, 22.28, 6.05, and 1.86 min at 70, 75, 80, and 85 °C, respectively. This research shows that the improved design of test cells is a reliable experimental tool to study the thermal resistance of microorganisms in low-a w foods. Accurate detection of microbial survival under isothermal conditions will provide reliable data for modeling and pathogen control during thermal processing to help ensure food safety and quality. • This research improved the previous design of aluminum test cell. • The new design has short come-up time, it is easy to load and unload food samples. • Custom tightening fixtures are applied for better opening and closing the cell. • The improved design is reliable to study the thermal resistance of bacteria. [ABSTRACT FROM AUTHOR]

This study was conducted to validate a simulated commercial whole wheat multigrain bread baking process at 375 °F (190.6 °C) oven temperature for 35 min to inactivate Salmonella , and to determine the thermal inactivation parameters of a 7-serovar Salmonella cocktail in whole wheat multigrain bread dough. A ≥5-log CFU/g reduction in Salmonella population was achieved by 15 min, and no viable Salmonella was detected after enrichment plating by 16 min. The a w of the bread crumb (0.96) after baking and 60 min of cooling was similar to that of pre-baked bread dough, whereas the a w of bread crust decreased to 0.81 at the end of baking and cooling. The D-values of the Salmonella cocktail in bread dough were 59.6, 20.0 and 9.7 min at 50, 52 and 55 °C, respectively; and the z -value was 6.5 °C. • This study validated that baking whole wheat multigrain bread at >190 °C oven temperature for at least 16 min will control the risk of Salmonella. • Bread water activity profiles on the surface and inside varied during the baking process. • D and z values of Salmonella could provide the basic information on the thermal resistance at the start of the baking process. [ABSTRACT FROM AUTHOR]

Improper food processing is one of the major causes of foodborne illness. Accurate prediction of the thermal destruction rate of foodborne pathogens is therefore vital to ensure proper processing and food safety. When bacteria are subjected to pH and thermal stresses during growth, sublethal stresses can occur that may lead to differences in their subsequent tolerance to thermal treatment. As a preliminary study to test this concept, the current study evaluated the effect of prior pH and thermal stresses on thermal tolerance of Salmonella and Staphylococcus using a tryptic soy broth supplemented with yeast extract. Bacteria incubated at three pH values (6.0, 7.4, and 9.0) and four temperatures (15, 25, 35, and 45°C) for 24 hr were subjected to thermal treatments at 55, 60, and 65°C. At the end of each treatment time, bacterial suspensions were surface‐plated on standard method agar for quantification of bacterial survival and further calculation of the thermal death decimal reduction time (D‐value) and thermal destruction temperature (z‐value). The effect of pH stress alone during the incubation on the thermal tolerance of both bacteria was generally insignificant. An increasing pattern of D‐value was observed with the increment of thermal stress (incubation temperature). The bacteria incubated at 35°C required the highest z‐value to reduce the 90% in D‐values. Staphylococcus mostly displayed higher tolerance to thermal treatment than Salmonella. Although further research is needed to validate the current findings on food matrices, findings in this study clearly affirm that adaptation of bacteria to certain stresses may reduce the effectiveness of preservation procedures applied during later stage of food processing and storage. [ABSTRACT FROM AUTHOR]

Highlights • Convolution of exponential distributions described the time required for a specific decrease in the number of cells. • Variability in the number of survivors has followed a Poisson distribution. • Although there are some differences between the probabilistic approach and the kinetic method, the difference is less than 5% when the probability of a population containing survivors is below 0.1. Abstract The traditional log-linear inactivation kinetics model considers microbial inactivation as a process that follows first-order kinetics. A basic concept of log reduction is decimal reduction time (D -value), which means time/dose required to kill 90% of the relevant microorganisms. D -value based on the first-order survival kinetics model is insufficient for reliable estimations of bacterial survivors following inactivation treatment. This is because the model does not consider the inactivation curvature and variability in bacterial inactivation. However, although the D -value has some limitations, it is widely used for risk assessment and sterilization time estimation. In this study, stochastic inactivation models are used in place of the conventional D -value to describe the probability of a population containing survivors. As representative bacterial inactivation normally follows a log-linear or log-Weibull model, we calculate the time required for a specific decrease in the number of cells and the number of survival cells as a probability distribution using the stochastic inactivation of individual cells in a population. We compare the probability of a population containing survivors calculated via the D -value, an inactivation kinetics model, and the stochastic formula. The stochastic calculation can be approximately estimated via a kinetic curvature model with less than 5% difference below the probability of a population containing survivors 0.1. This stochastic formula indicates that the D -value model would over- or under-estimate the probability of a population containing survivors when applied to inactivation kinetics with curvature. The results presented in this study show that stochastic analysis using mathematical models that account for variability in the individual cell inactivation time and initial cell number would lead to a realistic and probabilistic estimation of bacterial inactivation. [ABSTRACT FROM AUTHOR]

Abstract This study was conducted to validate a commercial nut muffin baking process and to compare the survival of a 7-serovar Salmonella cocktail when contaminated via inoculated flour or walnuts. Enriched wheat flour or walnut pieces were mist inoculated with the Salmonella cocktail and dried back to the pre-inoculation weight, resulting in a Salmonella population level of 6.9 and 8.4 log CFU/g, respectively. Nut muffin batters were prepared separately using inoculated flour or walnuts, followed by baking at 375 °F (190.6 °C) oven temperature for 21 min and post-bake ambient air-cooling (B + C). During baking, >5-log CFU/g reductions in the Salmonella population in nut muffins was achieved in 17 min, and Salmonella was not detected by direct plating (<0.2 log CFU/g detection limit) but was recovered by enrichment at the end of 21 min of baking and B + C. In a separate baking study using an extended baking time (24 min) at 375 °F, Salmonella was detected after 24 and 22 min using enrichment plating of nut muffins prepared from inoculated flour and walnuts, respectively. The D-values of the Salmonella cocktail in nut muffin batters prepared from inoculated flour were 24.0, 4.0 and 0.6 min at 60, 65 and 70 °C; whereas, corresponding D-values in batters prepared from inoculated walnuts were 22.0, 3.6 and 1.7 min. The z -values of the Salmonella cocktail in nut muffin batters were 6.1 and 9.0 °C for inoculated flour and walnuts, respectively. This simulated commercial nut muffin baking study utilizing an oven temperature of 190.6 °C for at least 17 min validates that the process will eliminate Salmonella populations by ≥5 log CFU/g if pre-baking contamination occurs via flour or walnut ingredients. Highlights • This study validated that baking nut muffins >190° • The D- and z -values of Salmonella determined could be useful for validating similar muffin baking processes. [ABSTRACT FROM AUTHOR]

Human noroviruses (HNoVs) cause significant gastrointestinal disease outbreaks worldwide. Tulane virus (TV) is a cultivable HNoV surrogate widely used to determine control measures against HNoVs. The objective of this study was to determine the heat inactivation kinetics (D‐ and z‐values) of TV in cell‐culture media and on spiked homogenized spinach using the first‐order and Weibull models. TV in cell‐culture media at approximately 7 log PFU/mL (PFU—plaque forming unit) in 2‐mL glass vials was heated at 52, 54, and 56 °C for up to 10 min in a circulating water bath. Survivors were enumerated using confluent host LLC‐MK2 cells in six‐well plates by plaque assay. Data from three replicate treatments assayed in duplicate were analyzed statistically. D‐values by the first‐order model for TV in cell‐culture media at 52, 54, and 56 °C were 4.59 ± 0.05, 2.91 ± 0.05, and 1.74 ± 0.07 min, respectively, with a z‐value of 9.09 ± 0.01 °C (R2 = 0.997). The Weibull model showed td = 1 values of 2.53 ± 0.08, 1.99 ± 0.10, and 0.57 ± 0.64 min, respectively, at the same temperatures. The D‐values for TV in spinach were 7.94 ± 0.21, 4.09 ± 0.04, and 1.43 ± 0.02 min and the z‐value was 10.74 ± 0.01 °C (R2 = 0.98) by the first‐order model and 4.89 ± 0.02, 3.21 ± 0.45, and 0.25 ± 0.38 min for the Weibull model at 50, 54, and 58 °C, respectively. In comparison to previously reported results for the cultivable HNoV surrogate, murine norovirus ‐1, TV in cell‐culture media and spiked on spinach homogenates showed lower D‐ and z‐values. TV may not be an ideal HNoV surrogate for heat inactivation studies in cell‐culture media or homogenized spinach in vacuum bags. [ABSTRACT FROM AUTHOR]

Brazilian legislation allows the manufacture of raw milk cheese with a maturation exceeding 60 days at room temperature above 5°C, but there is a lack of solid scientific evidence on the efficacy of this maturation process in inactivating important pathogens that may be present in milk, such as Mycobacterium bovis and Brucella abortus. Thus, the objectives of this study were to produce parmesan-type cheese experimentally contaminated with M. bovis and B. abortus and evaluate the survival of these pathogens along 2-month maturation. Parmesan-type cheese was manufactured in the laboratory using whole pasteurized milk with or without inoculation with M. bovis (SB1033) or B. abortus (1119-3) and matured at 18°C for up to 63 days. M. bovis was inoculated in Stonebrink-Leslie medium supplemented with antibiotics and incubated at 37°C for 45 days, and B. abortus was incubated in Farrel medium at 36°C for 3 days. The average D18°C value, weighted by variance, was 37.5 ± 5.3 days for M. bovis and 5.9 ± 0.7 days for B. abortus. The average physicochemical parameters in the cheese at the end of the study were as follows: pH = 4.89, water activity = 0.976, and moisture percentage = 43.1%. The pH might have contributed to the reduction in the population of B. abortus but seems not to have influenced the population of M. bovis. We conclude that the duration of the maturation process influences the size of the surviving populations of M. bovis and B. abortus, and that the shortening of the maturation duration might not ensure a decline in pathogen levels to safe levels. Thus, complementary studies considering the effect of several other technological aspects on the survival of these pathogens are required, including the effect of the lactic acid bacterial population, salt content, and temperature of maturation.

While filtration, chlorination, and UV drinking water treatments are commonplace, globally an estimated 1.2 billion people continue to boil their drinking water over inefficient biomass fires instead because it allows them to use available resources paired with a time-tested and trusted method. Although boiling water is culturally well-established, there is vast potential to improve human health, environmental impact, and efficiency by leveraging the fact that a significant reduction in pathogenic microorganisms occurs at temperatures well below boiling through a process known as pasteurization. This paper presents the evaluation of a community-scale, biomass-powered, flow-through water pasteurization system that was designed to heat water to the temperature required for pasteurization to occur before recuperating heat while cooling treated water down to a safe-to-handle temperature. The system is then compared to other common thermal treatment methods including batch-boiling over open fires and improved cookstoves. Results from computational modeling and empirical analysis show that the water pasteurizer significantly increases the overall water treatment capacity (from 7.9 to 411 L/h, adjusted for one hour of treatment via household boiling and operation of the water pasteurizer at steady-state, respectively) and uses far less biomass fuel (from 22 to 5.5 g/L, adjusted for treatment of 1 L of water via household boiling and operation of the water pasteurizer at steady-state, respectively). Notable comparisons to the batch-boiling of water over institutional-sized traditional and improved cookstoves are also demonstrated. Further, the results of fecal indicator reduction through the system (8 log and 6 log reduction of E. coli and bacteriophage MS2, respectively) suggest compliance with US-EPA (6 log and 4 log reduction of E. coli and bacteriophage MS2, respectively) and WHO requirements (effluent concentrations below the detection limit, specified as E. coli CFU/100 mL and E. coli and bacteriophage for water treatment processes. It is recommended that engineers continue to explore the use of heat transfer and microorganism reduction theory to design technologies that increase the capacity and efficiency for thermal water purification that uses locally-available biomass resources.