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Tubers and roots have been used in human nutrition since ancient times once they are resistant to pests and easy to grow even in soils poor in nutrients. The most consumed include cassava, potatoes, taro, and yam. In many regions, they are the main source of energy, which has led to industrial-scale cultivation of some such as yacon, burdock, Jerusalem and artichoke, known as sources of fructooligosaccharides, due to the increased demand for prebiotic fibers and the need for lower energy foods. This chapter will present a general approach to tubers and roots and their important role in human nutrition. At the end of the chapter, those recognized as prebiotics and the processing methods for extracting fibers will be discussed. [ABSTRACT FROM AUTHOR]

Unit operations modify material properties aiming to produce uniform and high-quality food products with greater acceptance by the increasingly demanding consumers or with longer shelf life and better possibilities of storage and transport. Microorganisms, including bacteria, molds, viruses, and parasites, may have different susceptibilities to unit operations employed during food processing. On-farm (cleaning, selection and classification, cooling, storage, and transport) and on-factory unit operations (heating, refrigeration/freezing, dehydration, modification of atmosphere, irradiation, and physical, chemical, and microbial-based operations) are commonly employed throughout food production chain. The intensity and combination of unit operations along with food composition, packaging, and storage conditions will influence on the dominance of specific microorganisms, which can be pathogenic or responsible for spoilage. Thus, in the context of food safety objective (FSO), the knowledge and the quantification of the effects caused by each step of processing can enable to control and ensure the quality and safety of manufactured products. [ABSTRACT FROM AUTHOR]

Some Escherichia coli serotypes are important human pathogens causing diarrhea or in some cases, life threatening diseases. E. coli is also a typical indicator microorganism, routinely used for assessing the microbiological quality of water especially to indicate fecal contamination. The soil is a sink and route of transmission to water and food resources and it is thus important to understand the survival of enterotoxigenic E. coli strains in soil. This study monitored the survival of six E. coli strains in sandy and loam soil. Furthermore, since biochar is a commonly used soil conditioner, the study investigated the impact of biochar amendment (15%) on the survival of the E. coli strains in (biochar-amended) sandy and loam soils. Addition of biochar affected the physicochemical properties of both soils, altering potassium levels, calcium, magnesium, sodium as well as levels of other metal ions. It increased the organic matter of loam soil from 44 g/dm3 to 52 g/dm3, and increased the pH of both sandy and loam soils. Survival and persistence of the E. coli strains generally varied according to soil type, with strains generally surviving better (P ≤ 0.05) in loam soil compared to in sandy soil. In loam soil and biochar amended loam soils, E. coli strains remained culturable until the 150th day with counts ranging between 3.00 and 5.94 ± 0.04 log CFU/g. The effects of biochar on the physicochemical properties of soil and the response of the E. coli strains to biochar amendment was variable depending on soil type. • E. coli exhibits variable survival behavior in soil based on soil type and biochar amendment. • Soil type significantly influence the survival of E. coli in soil. • E. coli strains survived for up to 150 days in loam soil. • Biochar application does not exert uniform impact on the survival of the six test E. coli strains in soil. [ABSTRACT FROM AUTHOR]

Contaminated irrigation water is among many potential vehicles of human pathogens to food plants, constituting significant public health risks especially for the fresh produce category. This review discusses some available guidelines or regulations for microbiological safety of irrigation water, and provides a summary of some common methods used for characterizing microbial contamination. The goal of such exploration is to understand some of the considerations that influence formulation of water testing guidelines, describe priority microbial parameters particularly with respect to food safety risks, and attempt to determine what methods are most suitable for their screening. Furthermore, the review discusses factors that influence the potential for microbiologically polluted irrigation water to pose substantial risks of pathogenic contamination to produce items. Some of these factors include type of water source exploited, irrigation methods, other agro ecosystem features/practices, as well as pathogen traits such as die-off rates. Additionally, the review examines factors such as food safety knowledge, other farmer attitudes or inclinations, level of social exposure and financial circumstances that influence adherence to water testing guidelines and other safe water application practices. A thorough understanding of relevant risk metrics for the application and management of irrigation water is necessary for the development of water testing criteria. To determine sampling and analytical approach for water testing, factors such as agricultural practices (which differ among farms and regionally), as well as environmental factors that modulate how water quality may affect the microbiological safety of produce should be considered. Research and technological advancements that can improve testing approach and the determination of target levels for hazard characterization or description for the many different pollution contexts as well as farmer adherence to testing requirements, are desirable. [ABSTRACT FROM AUTHOR]

Abstract: The growth parameters (growth rate, μ and lag time, λ) of three different strains each of Salmonella enterica and Listeria monocytogenes in minimally processed lettuce (MPL) and their changes as a function of temperature were modeled. MPL were packed under modified atmosphere (5% O2, 15% CO2 and 80% N2), stored at 7–30 °C and samples collected at different time intervals were enumerated for S. enterica and L. monocytogenes. Growth curves and equations describing the relationship between μ and λ as a function of temperature were constructed using the DMFit Excel add-in and through linear regression, respectively. The predicted growth parameters for the pathogens observed in this study were compared to ComBase, Pathogen modeling program (PMP) and data from the literature. High R2 values (0.97 and 0.93) were observed for average growth curves of different strains of pathogens grown on MPL. Secondary models of μ and λ for both pathogens followed a linear trend with high R2 values (>0.90). Root mean square error (RMSE) showed that the models obtained are accurate and suitable for modeling the growth of S. enterica and L. monocytogenes in MP lettuce. The current study provides growth models for these foodborne pathogens that can be used in microbial risk assessment. [Copyright &y& Elsevier]

Abstract: Minimally processed vegetables (MPV) may be important vehicles of Salmonella spp. and cause disease. This study aimed at detecting and enumerating Salmonella spp. in MPV marketed in the city of São Paulo, Brazil. A total of 512 samples of MPV packages collected in retail stores were tested for Salmonella spp. and total coliforms and Escherichia coli as indication of the hygienic status. Salmonella spp. was detected in four samples, two using the detection method and two using the counting method, where the results were 8.8 × 102 CFU/g and 2.4 × 102 CFU/g. The serovars were Salmonella Typhimurium (three samples) and Salmonella enterica subsp. enterica O:47:z4,z23:- (one sample). Fourteen samples (2.7%) presented counts of E. coli above the maximum limit established by the Brazilian regulation for MPV (102 CFU/g). Therefore, tightened surveillance and effective intervention strategies are necessary in order to address consumers and governments concerns on safety of MPV. [Copyright &y& Elsevier]

Abstract Brazilian artisanal cheeses are characterized by the use of raw milk and in some cases, natural starter cultures, known as "pingo", as well as following simple and traditional manufacturing technology. In this study, a large-scale screening of the microbial ecology of 11 different types of artisanal cheeses produced in five geographical areas of Brazil was performed. Besides, the specific origin-related microbial signatures were identified. Clear geography- and technology-based differences in the microbiota were observed. Lactic acid bacteria dominated in all cheeses although Enterobacteriaceae and Staphylococcus also occurred in North, Northeast and Central cheeses. Differences in the lactic acid bacteria patterns were also highlighted: Streptococcus , Leuconostoc , Lactococcus and Lactobacillus were differently combined in terms of relative abundance according to product type and region of production. This study provides a comprehensive, unprecedented microbiological mapping of Brazilian cheeses, highlighting the impact of geographical origin and mode of production on microbial diversity. The results obtained will help to plan an evaluation of microbial contamination sources that will need to be studied for the improvement of cheese quality and safety. Highlights • First wide-range study of microbial diversity in Brazilian artisanal cheeses (BAC). • The cheese microbiota varied with the type of cheese and region of production. • The main genera found in the cheeses were Streptococcus , Leuconostoc and Lactococcus. • Core of bacterial genera was identified in cheeses from different production regions. • Oligotyping allowed identifying 15 Lactobacillus species in the different cheeses. [ABSTRACT FROM AUTHOR]

Foodborne illness resulting from the consumption of contaminated fresh produce is a common phenomenon and has severe effects on human health together with severe economic and social impacts. The implications of foodborne diseases associated with fresh produce have urged research into the numerous ways and mechanisms through which pathogens may gain access to produce, thereby compromising microbiological safety. This review provides a background on the various sources and pathways through which pathogenic bacteria contaminate fresh produce; the survival and proliferation of pathogens on fresh produce while growing and potential methods to reduce microbial contamination before harvest. Some of the established bacterial contamination sources include contaminated manure, irrigation water, soil, livestock/ wildlife, and numerous factors influence the incidence, fate, transport, survival and proliferation of pathogens in the wide variety of sources where they are found. Once pathogenic bacteria have been introduced into the growing environment, they can colonize and persist on fresh produce using a variety of mechanisms. Overall, microbiological hazards are significant; therefore, ways to reduce sources of contamination and a deeper understanding of pathogen survival and growth on fresh produce in the field are required to reduce risk to human health and the associated economic consequences. [ABSTRACT FROM AUTHOR]

This study gathered information on the practices employed in Brazilian processing plants during production of ready-to-eat (RTE) vegetables and evaluated the effect of washing practices on the quality of RTE vegetables produced in these plants. Physicochemical analysis of water included temperature, pH, organic load and chlorine concentration and microbiological analysis included mesophilic bacteria, yeasts and molds, Enterobacteriaceae , total coliforms, Escherichia coli and Salmonella . The ten selected processing plants were clustered in three groups: 1) plants A, B, D, H and I, where washing procedures included immersion in agitated tanks during pre-washing and washing-disinfection and use of disinfectant in the pre-washing step; 2) plant E, where vegetables were washed under running water in the pre-washing step, sodium hypochlorite was used as a disinfectant agent and processing of vegetables was only manual; and 3) plants C, F, G and J, where pre-washing and washing-disinfection were performed by immersion in water, followed by a rinsing step. Chlorine was the most used chemical agent for disinfection of vegetables. A 0.2–1.2 log reduction was achieved by the practices adopted in the plants, highlighting the importance of immediate refrigeration and control measures to avoid post-processing recontamination. [ABSTRACT FROM AUTHOR]

This study aimed to assess the bacterial microbiota involved in the spoilage of pacu (Piaractus mesopotamics), patinga (female Piaractus mesopotamics x male Piaractus brachypomus), and tambacu (female Colossoma macropomum × male Piaractus mesopotamics) during ice and frozen storage. Changes in the microbiota of three fish species (N = 22) during storage were studied through 16S rRNA amplicon-based sequencing and correlated with volatile organic compounds (VOCs) and metabolites assessed by nuclear magnetic resonance (NMR). Storage conditions (time and temperature) affected the microbiota diversity in all fish samples. Fish microbiota comprised mainly of Pseudomonas sp. , Brochothrix sp. , Acinetobacter sp. , Bacillus sp. , Lactiplantibacillus sp. , Kocuria sp., and Enterococcus sp. The relative abundance of Kocuria , P. fragi , L. plantarum, Enterococcus , and Acinetobacter was positively correlated with the metabolic pathways of ether lipid metabolism while B. thermosphacta and P. fragi were correlated with metabolic pathways involved in amino acid metabolism. P. fragi was the most prevalent spoilage bacteria in both storage conditions (ice and frozen), followed by B. thermosphacta. Moreover, the relative abundance of identified Bacillus strains in fish samples stored in ice was positively correlated with the production of VOCs (1-hexanol, nonanal, octenol, and 2-ethyl-1-hexanol) associated with off-flavors. 1H NMR analysis confirmed that amino acids, acetic acid, and ATP degradation products increase over (ice) storage, and therefore considered chemical spoilage index of fish fillets. • Microbiota in pacu, patinga and tambacu were influenced by ice and frozen storage. • Fish microbiota was dominated by Pseudomonas and Brochothrix. • VOCs studied were positive correlated with Bacillu s spp. • Metabolites (1H NMR) increased during storage can be used as spoilage biomarkers. [ABSTRACT FROM AUTHOR]

This study aimed to assess the impact of adaptation of ten strains of O157:H7 and non-O157 Escherichia coli to low pH (acid shock or slow acidification) and the effects of this exposure or not on the resistance of E. coli strains to UV radiation in orange juice (pH 3.5). The acid-shocked cells were obtained through culture in tryptic soy broth (TSB) with a final pH of 4.8, which was adjusted by hydrochloric, lactic, or citric acid and subsequently inoculated in orange juice at 4 °C for 30 days. No significant differences (p > 0.05) in survival in orange juice were observed between the serotypes O157:H7 and non-O157:H7 for acid-shocked experiments. After slow acidification, where the cells were cultured in TSB supplemented with glucose 1% (TSB + G), a significant increase (p < 0.05) in survival was observed for all strains evaluated. The D-values (radiation dose (J/cm2) necessary to decrease the microbial population by 90%) were determined as the inverse of the slopes of the regressions (k) obtained by plotting log (N/N 0). The results show that among the strains tested, E. coli O157:H7 (303/00) and O26:H11 were the most resistant and sensitive strains, respectively. According to our results, the method of acid adaptation contributes to increasing the UV resistance for most of the strains tested. • Slow acidity is more efficient than acid shock to acid adaptation of the cells. • Cell survival in orange juice differs according to the acid used after acid shock. • Resistance to UV radiation was increased by acid adaptation. [ABSTRACT FROM AUTHOR]

The loss of probiotics viability in yogurts and fermented milk is a significant challenge in producing yogurt and fermented milk. Thus, pre-exposure of probiotics to stress conditions can be a viable alternative to increase the probiotic viability. Moreover, the use of fruit pulp and agro-industrial residues in these products has demonstrated promising results in promoting growth and improving the viability of probiotics. Thus, this study aimed to evaluate the effects of pre-exposure to acid, oxidative and osmotic stress on the growth and viability of Lactobacillus acidophilus in yogurts and naturally fermented milk containing buriti (Mauritia flexuosa Mart.) pulp or orange byproduct. L. acidophilus was individually pre-exposed to acid, oxidative, and osmotic stress and used in the production of yogurts and fermented milk to determine both the acidification profile and growth of the cultures. Furthermore, during cold storage, the post-acidification profiles and viability of microbial cultures added to the yogurts and fermented milk were monitored. Results showed that pre-exposure to stress conditions influenced the growth parameters as the growth rate (μ) and lag phase (λ) of L. acidophilus and the starter cultures of S. thermophilus and L. delbrueckii subsp. bulgaricus. Moreover, an increase in the viability of L. acidophilus - pre-exposed to acid stress - was observed on the 21st day of storage of natural yogurts containing orange byproduct compared with non-stressful conditions. This study reports new data on the growth of probiotic cultures pre-exposed to stress conditions in products added of pulps and agro-industrial residues, which have not yet been shown in the literature. • Pre-exposure to acidic, oxidative, and osmotic stress impacts L. acidophilus (La) growth during milk fermentation. • The pre-exposure of L. acidophilus to stressful conditions influences starter culture growth during yogurt production. • Survival of L. acidophilus under acid stress before exposure in yogurts with orange by-product during 21 days of cold storage. • Orange byproduct and buriti pulp promote probiotic growth during fermented milk production. [ABSTRACT FROM AUTHOR]

The present study aimed to assess the occurrence and counts of Staphylococcus aureus in Brazilian artisanal cheeses (BAC) produced in five regions of Brazil: Coalho and Manteiga (Northeast region); Colonial and Serrano (South); Caipira (Central-West); Marajó (North); and Minas Artisanal cheeses, from Araxá, Campos das Vertentes, Cerrado, Serro and Canastra microregions (Southeast). The resistance to chlorine-based sanitizers, ability to attach to stainless steel surfaces, and antibiogram profile of a large set of S. aureus strains (n = 585) were assessed. Further, a total of 42 isolates were evaluated for the presence of enterotoxigenic genes (sea, seb, sec, sed, see, seg, sei, sej , and ser) and submitted to typing using pulsed-field gel electrophoresis (PFGE). BAC presented high counts of S. aureus (3.4–6.4 log CFU/g), varying from 25 to 62.5%. From the S. aureus strains (n = 585) assessed, 16% could resist 200 ppm of sodium hypochlorite, whereas 87.6% produced strong ability to attach to stainless steel surfaces, corroborating with S. aureus ability to persist and spread in the environment. Furthermore, the relatively high frequency (80.5%) of multidrug-resistant S. aureus and the presence of enterotoxin genes in 92.6% of the strains is of utmost attention. It reveals the lurking threat of SFP that can survive when conditions are favorable. The presence of enterotoxigenic and antimicrobial-resistant strains of S. aureus in cheese constitutes a potential risk to public health. This result calls for better control of cheese contamination sources, and taking hygienic measures is necessary for food safety. More attention should be paid to animal welfare and hygiene practices in some dairy farms during manufacturing to enhance the microbiological quality of traditional cheese products. • oSanitizer resistance, attachment ability, and antibiogram of 585 S. aureus strains. • oCharacterization of strains by nine enterotoxigenic genes and PFGE profile. • o S. aureus counts varied from 3.4 to 6.4 log CFU/g while incidence varied from 25 to 62.5%. • o16% of S. aureus resisted 200 ppm of chlorine and 87.6% attached to stainless steel. • oMost S. aureus were multidrug-resistance (80.5%) and had enterotoxin genes (92.6%). [ABSTRACT FROM AUTHOR]

Sporeforming bacteria are a concern in some food raw materials, such as cocoa powder. Samples (n = 618) were collected on two farms and at several stages during cocoa powder manufacture in three commercial processing lines to determine the impact of each stage on bacterial spore populations. Mesophilic aerobic, mesophilic anaerobic, thermophilic aerobic, and Bacillus cereus spore populations were enumerated in all the samples. Genetic diversity in B. cereus strains (n = 110) isolated from the samples was examined by M13 sequence-based PCR typing, partial sequencing of the panC gene, and the presence/absence of ces and cspA genes. The counts of different groups of sporeforming bacteria varied amongst farms and processing lines. For example, the counts of mesophilic aerobic spore-forming (MAS) populations of cocoa bean fermentation were lower than 1 log spore/g in Farm 1 but higher than 4 log spore/g in Farm 2. B. cereus isolated from cocoa powder was also recovered from cocoa beans, nibs, and samples after roasting, refining, and pressing, which indicated that B. cereus spores persist throughout cocoa processing. Phylogenetic group IV was the most frequent (73%), along with processing. Strains from phylogenetic group III (14 %) did not show the ces gene's presence. • The effects of process on levels of spore-forming bacteria (SPB) was investigated. • Cocoa samples (n = 618) were collected in two farms and three industrial lines. • Four groups of SPB studied were aerobic mesophilic and thermophilic, B. cereus and anaerobic mesophilic. • The occurrence and counts of SPB varied with the cocoa farm and processing line. • B. cereus found in farms and processing lines were also recovered from cocoa powder samples. [ABSTRACT FROM AUTHOR]

This study aimed to assess the effect of water activity (a w) (0.93–0.95), pH (5.1–5.8), and concentration of calcium propionate (0.25 and 0.41%) on the germination time of individual spores of Penicillium paneum. The germination of single spores was examined by capturing images at every hour using the Axio Observer.Z1 inverted microscope (× 100) connected to the camera at 25 °C for 96 h. The results indicated that P. paneum germination time was significantly affected by a w and pH (ρ < 0.05). As most of the growth curves exhibited asymmetric shapes, the asymmetric model was fitted to germination data and the maximum percentage of viable spores (P max ; %), shape parameter (d), and germination time (τ; hour) were obtained. τ -values ranged from 26.5 to 40.7 h. After the Monte Carlo simulation, a probability distribution of time for 10% of the P. paneum population (t 10%) to germinate was obtained. The mean value of t 10% was 25 h, ranging from 15 to 47 h (95% confidence interval). The variability in germination and growth of P. paneum single spores highlights the challenge of predicting and preventing this critical phenomenon. • Penicillium paneum single cell modeling as affected by a w , pH, calcium propionate. • % of viable spores (P max), shape parameter (d), germination time (τ) were found. • τ –values of P. paneum ranged from 26.5 to 40.7 h and were affected by a w and pH. • Probability distribution of germination time for 10% of P. paneum varied 15–47 h. • Single spore modeling can be useful to assess the heterogenous behavior of fungi. [ABSTRACT FROM AUTHOR]

This work aimed to estimate the inactivation kinetic parameters of four potential beer spoilage bacteria (Lactobacillus brevis DSM 6235 , Lactobacillus casei ATCC 334, Pediococcus damnosus DSM 20289 and Pediococcus damnosus ATCC 29358) inoculated in brewing yeast submitted to acid washing with purposes of yeast recycle. The experiments were conducted at 4 °C in solutions with pH 1.5, pH 2, and pH 3 adjusted employing 85% phosphoric acid. The acid washing treatment of brewing yeasts in the most common pH used (pH 2.0) demanded almost 50 min for the first decimal reduction (δ) of L. brevis DSM 6235. Sensible strains to acid washing such as P. damnosus DSM 20289 demanded almost 70 min for 4 log reductions to be achieved. On the other hand, pH reduction of the acid washing from 2.0 to 1.5 allowed 4 log reduction of L. brevis DSM 6235) to be obtained in less than 50 min , without ruining brewer's yeast viability. Acid washing in pH 1.5 is a viable method for the inactivation of bacterial contaminants of brewing yeasts. Recycling of brewing yeasts through this approach may contribute to a more sustainable and environmental-friendly industry. • Inactivation of beer spoilage bacteria in brewing yeast acid washing was assessed. • Washing with phosphoric acid were conducted at 4 °C with pH 1.5, pH 2, and pH 3. • δ of Lactobacillus were 4–7 times higher than Pediococcus in washing in pH 1.5 • Time for 4 log reduction was ~50 min for L. brevis DSM 6235 in washing in pH 1.5 • Washing with pH 1.5 inactivates contaminants and allows recycle of brewing yeasts. [ABSTRACT FROM AUTHOR]

This study determined the susceptibility to sanitizers and biofilm-forming ability on stainless steel of 43 Salmonella enterica and Listeria monocytogenes strains. Besides, the biofilm resistance to sanitizers of four bacterial pathogen strains was evaluated. Four sanitizers commonly used in the food industry were tested: peracetic acid (PAA), chlorine dioxide (ClO 2), sodium hypochlorite (SH), and quaternary ammonium compound (QAC). The susceptibility to sanitizers varied widely among the strains of both pathogens. On the other hand, the number of biofilm-associated cells on the stainless-steel surface was >5 log CFU/cm2 for all of them. Only one Salmonella strain and two L. monocytogenes strains stood out as the least biofilm-forming. The resistance of biofilms to sanitizers also varied among strains of each pathogen. Biofilms of L. monocytogenes were more susceptible to the disinfection process with ClO 2 and QAC than those of Salmonella. However, no correlation was observed between the ability to form denser biofilm and increased sanitizer resistance. In general, chlorine compounds were more effective than other sanitizers in inactivating planktonic cells and biofilms. • Biofilm formation and tolerance to sanitizers of 43 strains were assessed • L. monocytogenes strains were more susceptible to sanitizers than Salmonella • ClO 2 was more effective than QAC against Salmonella and L. monocytogenes strains • Biofilms of both pathogens showed high variability for resistance to sanitizers • The ability to form denser biofilm did not correlate with resistance to sanitizers [ABSTRACT FROM AUTHOR]

This study assessed the adhesion and formation of biofilm by five Salmonella enterica strains (S. Enteritidis 132, S. Infantis 176, S. Typhimurium 177, S. Heidelberg 281 and S. Corvallis 297) on polypropylene (PP) and glass (G) surfaces as affected by pH (4–7), NaCl concentration (0–10% w/v) and temperature (8–35 °C). Sessile counts <3 log CFU/cm2 were considered lack of adhesion (category 1), while counts ≥ 3 and < 5 log CFU/cm2 corresponded to adhesion (category 2) and counts ≥ 5 log CFU/cm2 corresponded biofilm formation (category 3). The obtained results categorized in these three responses were used to develop ordinal regression models to predict the probability of biofilm stages on PP- and G-surfaces. The experimental outcomes for lack of adhesion were >90% on PP- and G-surfaces. Generally, adhesion outcomes corresponded to approximately 36% of the total, whereas biofilm outcomes were close to 65% in both PP- and G-surfaces. The biofilm stages varied among the strains studied and with the material surface under the same experimental conditions. According to the generated ordinal models, the probability of adhesion and biofilm formation on PP-surface by the five S. enterica strains tested decreased at pH 4 or 5 in NaCl concentrations >4% and at a temperature <20 °C. On G-surface, the probability of adhesion increased pH 6 or 7, in the absence of NaCl and temperatures <20 °C, while, the probability of biofilm formation increased in the same pH, NaCl concentration up to 4% and temperatures ≥20 °C. This is the first study assessing the biofilm formation through categorical, ordinal responses and it shows that ordinal regression models can be useful to predict biofilm stages of S. enterica as a function of pH, NaCl, and temperature or their interactions. • Biofilm formation on glass (G) or polypropylene (PP) varied among Salmonella serovars. • Salmonella serovars were able to adhere and form biofilm at pH 4 or 5 up to 6% NaCl. • Changes in pH, NaCl concentration or temperature (T) affect the biofilm stages. • Probability of adhesion on G increased at pH ≥ 6, absence of NaCl and T < 20 °C. • Probability of biofilm on PP decreased at pH 4 or 5, NaCl > 4% and T < 20 °C. [ABSTRACT FROM AUTHOR]

Salmonella enterica serotypes have been reported as the agent of various outbreaks occurred after the consumption of low water activity (a w) foods. When the pathogen encounters harsh conditions, several regulatory networks are activated through dynamic differential gene expression that lead to cell survival for prolonged periods. In this work, the transcriptome of S. enterica serovar Typhimurium using RNA-Seq, after cells' inoculation in four distinct types of low a w foods (milk chocolate, powdered milk, black pepper, and dried pet food), following storage at 25 °C per 24 and 72 h was studied. The findings of this study suggest that gene regulation is influenced by the food composition mainly in the first 24 h post-inoculum, proceeded by the induction of similar genes shared among all samples. It was possible to evaluate the differences on each type of food matrix regarding the bacteria adaptation, as well as the similarities provoked by low a w. The results reveal genes that may play key roles in response to desiccation in Salmonella , as well as the pathways in which they are involved. • RNA-Seq was performed in S. enterica after inoculum in four different types of food. • Macronutrients content affects mainly the first 24 h of S. enterica adaptation. • After 72 h inoculum, dehydration responses presented higher similar patterns. • Plasmidial genes of S. enterica SL1344 were highly induced after 72 h of inoculum. [ABSTRACT FROM AUTHOR]

Alkalization is a step of cocoa processing and consists of the use of alkali and high temperature to improve the sensorial and technological qualities of cocoa. Intense food processing can select spores, which can compromise safety and quality of the final product. Thus, the aim of this study was to evaluate the fate of B. cereus and G. stearothermophilus spores during the alkalization of pre-roasted (Pr) nibs (held at 120 °C) and unroasted (Ur) nibs (held at 90 °C) using potassium carbonate (0, 2, 4 and 6% w/w). In all conditions, log-linear inactivation kinetics with a tail was observed. The inactivation rate (k max) for B. cereus varied from 0.065 to 1.67 min−1, whereas the k max for G. stearothermophilus varied from 0.012 to 0.063 min−1. For both microorganisms, the lowest k max values were observed during Ur nibs alkalization. The carbonate concentration increase promoted k max values reduction. The highest tail values were observed for G. stearothermophilus in Ur nibs alkalization, reaching 3.04 log spores/g. Tail formation and low k max values indicated that cocoa alkalization does not cause significant reductions on bacterial spore population. Therefore, the microbiological control should be primarily ensured by the raw material quality and by avoiding recontamination in the cocoa chain. • Inactivation of SB in Pr (120 °C)/Ur (90 °C) with K 2 CO 3 (0–6%) were non log-linear. • Larger variations of k max for B. cereus than for G. stearothermophilus. • Pr nibs alkalization led to greater reduction of SB than Ur nibs alkalization. • For both SB, the lowest k max values were observed during Ur nibs alkalization. • Increase of K 2 CO 3 concentration led to reduction of k max values. [ABSTRACT FROM AUTHOR]

Bacillus cereus and Geobacillus stearothermophilus are spore-forming bacteria of concern for the quality and safety of cocoa-based foods, because of their frequent occurrence in raw materials and the capability of spores to withstand heat processing. Cocktails of spores of B. cereus and G. stearothermophilus strains were separately inoculated on cocoa beans and nibs and roasted using a laboratory equipment at 110 °C, 125 °C and 140 °C for up to 600 min to simulate an industrial roasting process. The period of time needed for the first log-reduction δ for the spores of the cocktail of B. cereus in cocoa nibs at 110 °C, 125 °C and 140 °C were 92.2 min, 30.5 min, and 17.2 min, respectively. In cocoa beans at 110 °C, 125 °C and 140 °C δ -values were 148.5 min, 55.9 min, and 23.3 min. The δ -values for the spores of the cocktail of G. stearothermophilus in cocoa nibs at 110 °C, 125 °C, and 140 °C were 105.0 min, 39.6 min and 30.4 min, respectively, and 183.6 min, 76.2 min and 49.1 min in cocoa beans at the same temperatures, respectively. The a w of cocoa nibs and cocoa beans ranged between 0.687 and 0.753 before roasting, and between 0.355 and 0.528 after roasting, respectively. The roasting process on beans or nibs applied in the cocoa industry may have a limited effect on the inactivation of naturally present spore-forming bacteria. • The fate of B. cereus and G. stearothermophilus during cocoa roasting was studied. • Roasting at 110, 125 and 140 °C was applied in inoculated cocoa beans and nibs. • Heat-resistance of both bacteria was poorly affected by temperature increase. • Heat-resistance in cocoa beans/nibs exceed values reported in aqueous environment. • Differences in resistance between both bacteria during roasting were marginal. [ABSTRACT FROM AUTHOR]

Abstract This study compares dynamic tertiary and competition models for L. monocytogenes growth as a function of intrinsic properties of a traditional Brazilian soft cheese and the inhibitory effect of lactic acid bacteria (LAB) during refrigerated storage. Cheeses were prepared from raw or pasteurized milk with or without the addition of selected LAB with known anti-listerial activity. Cheeses were analyzed for LAB and L. monocytogenes counts, pH and water activity (a w) throughout cold storage. Two approaches were used to describe the effect of LAB on L. monocytogenes : a Huang-Cardinal model that considers the effect of pH and a w variation in a dynamic kinetic analysis framework; and microbial competition models, including Lotka-Volterra and Jameson-effect variants, describing the simultaneous growth of L. monocytogenes and LAB. The Jameson-effect with γ and the Lotka-Volterra models produced models with statistically significant coefficients that characterized the inhibitory effect of selected LAB on L. monocytogenes in Minas fresh cheese. The Huang-Cardinal model [pH] outperformed both competition models. Taking a w change into account did not improve the fit quality of the Huang-Cardinal [pH] model. These models for Minas soft cheese should be valuable for future microbial risk assessments for this culturally important traditional cheese. Highlights • LAB with anti-listerial activity reduced the μ opt and Y max of L. monocytogenes. • Dynamic tertiary and competition models presented good fit quality. • Jameson-effect model with γ showed that LAB inhibited L. monocytogenes growth. • Lotka-Volterra model was significant for inhibition of L. monocytogenes. [ABSTRACT FROM AUTHOR]

The risk of fungal spoilage of sports drinks produced in the beverage industry was assessed using quantitative microbial spoilage risk assessment (QMSRA). The most relevant pathway was the contamination of the bottles during packaging by mould spores in the air. Mould spores' concentration was estimated by longitudinal sampling for 6 years (936 samples) in different production areas and seasons. This data was analysed using a multilevel model that separates the natural variability in spore concentration (as a function of sampling year, season, and area) and the uncertainty of the sampling method. Then, the expected fungal contamination per bottle was estimated by Monte Carlo simulation, considering their settling velocity and the time and exposure area. The product's shelf life was estimated through the inoculation of bottles with mould spores, following the determination of the probability of visual spoilage as a function of storage time at 20 and 30 °C using logistic regression. The Monte Carlo model estimated low expected spore contamination in the product (1.7 × 10−6 CFU/bottle). Nonetheless, the risk of spoilage is still relevant due to the large production volume and because, as observed experimentally, even a single spore has a high spoilage potential. The applicability of the QMSRA during daily production was made possible through the simplification of the model under the hypothesis that no bottle will be contaminated by more than one spore. This simplification allows the calculation of a two-dimensional performance objective that combines the spore concentration in the air and the exposure time, defining "acceptable combinations" according to an acceptable level of spoilage (ALOS; the proportion of spoiled bottles). The implementation of the model at the operational level was done through the representation of the simplified model as a two-dimensional diagram that defines acceptable and unacceptable areas. The innovative methodology employed here for defining and simplifying QMSRA models can be a blueprint for future studies aiming to quantify the risk of spoilage of other beverages with a similar scope. • A quantitative microbial spoilage risk assessment in a beverage factory was developed. • A Gamma-Poisson model for mould concentration in the air separated measurement error from variability. • Contamination with even a single mould spore should be avoided in the beverage. • The model predicts that less than one bottle per million would be contaminated. • A diagram defining acceptable zones is created to facilitate quality management. [ABSTRACT FROM AUTHOR]

In this study, the probability of occurrence of fumonisins in corn in the states of greatest production in Brazil was determined. The data were analyzed through quantitative risk analysis using the Monte Carlo simulation. The results indicated that there is a strong correlation between fumonisins contamination levels and the geographical region due to the influence of climatic characteristics, with temperature having the main influence. The Southern states presented higher risks of occurrence and concentration levels of fumonisins in corn due to the temperate climate with lower average temperature and higher relative humidity and precipitation indices. Cultivation in the best season indicates a significant reduction in the production of fumonisins when this period was evaluated, with average concentration levels up to 42% lower. The generated data are important for regulatory agencies and the agricultural sector, which needs to be aware that the chance of success in grain production depends on efficient planning of the growing season, mainly concerning the climatic conditions to which it is subject to minimize the risks. • Risk of fumonisins in corn was assessed using quantitative risk assessment; • Temperature plays a critical role in fumonisin incidence and level in corn; • Reduction in fumonisin of up to 42% when cultivation at the best time was assessed; • Strong correlation between fumonisins levels and the geographical region was found; • Low temperatures and high humidity increased the probability of fumonisin in corn. [ABSTRACT FROM AUTHOR]

Abstract This study aimed to develop predictive models to assess the growth response of Pencillium paneum LMQA-002 and Paecilomyces variotii LMQA-001 in wholemeal multigrain bread regarding moisture, pH, calcium propionate, temperature and time of storage. A complete factorial design was performed using slices of bread with different formulation: moisture (36; 38; 40; 42%), pH (5.1; 5.3; 5.5) and calcium propionate (0.6; 0.8 and 1%). The slices were inoculated with 102-103 spores following storage at 20 °C, 25 °C and 30 °C for up to 21 days. The degree of agreement between predictions and observations was >90% for both species. According to the results, the growth of P. paneum LMQA-002 and P. variotii LMQA-001 was inhibited for up to 21 days in bread formulations presenting pH (5.1), 36% moisture and 0.6% calcium propionate. The lower temperatures (20 °C and 25 °C) contributed to the growth of P. paneum LMQA-002 and storage at 30 °C favored the growth of P. variotii LMQA-001. Validation results showed correct predictions in 80% of the cases. A significant achievement of this study comprises the extension of wholemeal multigrain bread shelf-life from 12 to 21 days (>70% increase). Graphical abstract Image 1 Highlights • The responses of P. paneum and P. variotii in wholemeal breads have been assessed. • The effect of pH, calcium propionate, moisture and storage temperature were studied. • Both fungi were inhibited by reducing the moisture, pH and calcium propionate. • The predicted models were validated and predicted correctly in 80% of the cases. [ABSTRACT FROM AUTHOR]

Artisanal raw milk cheeses are highly appreciated dairy products in Brazil and ensuring their microbiological safety has been a great need. This study reports the isolation and characterization of lactic acid bacteria (LAB) strains with anti-listerial activity, and their effects on Listeria monocytogenes during refrigerated shelf-life of soft Minas cheese and ripening of semi-hard Minas cheese. LAB strains (n = 891) isolated from Minas artisanal cheeses (n = 244) were assessed for anti-listerial activity by deferred antagonism assay at 37 °C and 7 °C. The treatments comprised the production of soft or semi-hard Minas cheeses using raw or pasteurized milk, and including the addition of selected LAB only [ Lactobacillus brevis 2-392, Lactobacillus plantarum 1-399 and 4 Enterococcus faecalis (1-37, 2-49, 2-388 and 1-400)], L. monocytogenes only, selected LAB co-inoculated with L. monocytogenes , or without any added cultures. At 37 °C, 48.1% of LAB isolates showed anti-listerial capacity and 77.5% maintained activity at 7 °C. Selected LAB strains presented a bacteriostatic effect on L. monocytogenes in soft cheese. L. monocytogenes was inactivated during the ripening of semi-hard cheeses by the mix of LAB added. Times to attain a 4 log-reduction of L. monocytogenes were 15 and 21 days for semi-hard cheeses produced with raw and pasteurized milk, respectively. LAB with anti-listerial activity isolated from artisanal Minas cheeses can comprise an additional barrier to L. monocytogenes growth during the refrigerated storage of soft cheese and help shorten the ripening period of semi-hard cheeses aged at ambient temperature. [ABSTRACT FROM AUTHOR]

In this study, the use of soybean extract on production and physicochemical characteristics of kefir was assessed. Also, the growth parameters of yeasts and lactic acid bacteria (LAB) during fermentation were evaluated. Experiments were carried out combining water-soluble soybean extract (S) and milk (M), leading to the evaluation of total or partial replacement of milk (formulations 100%S, 50%S50%M) a control formulation (100%M). During kefir fermentation, physicochemical analysis carried out as well as enumeration of yeasts and LAB. In all formulations, lactic acid concentration increased due to carbohydrates consumption by kefir microorganisms resulting in decrease of soluble solids content and increase of acidity. The final acidity of beverages varied from 0.600 to 0.738 g of lactic acid/100 mL and soluble solids ranged from 6.40 to 5.67 °Brix. Formulations 100%S and 100%M presented LAB counts of 8 log 10  CFU/mL. LAB lag time increased in formulation 50%S50%M compared to formulations 100%S and 100%M (2.20 h, 1.03 h and 1.06 h, respectively). LAB and yeasts growth parameters were not affected in beverages prepared with milk and soybean kefir. This is the first study that examined the yeast and LAB growth parameters using water-soluble soybean extract fermented with kefir. [ABSTRACT FROM AUTHOR]

The effect of supercritical dioxide carbon technology (SCCD, 14, 16, and 18 MPa, 35 ± 2 °C/10 min) on the physical properties (color, particle size, rheology tests and physical stability) and sensory acceptance (consumer test) of whey grape juice drink was investigated. Lower particle diameter and consistency index as well as a pseudoplastic behavior was obtained suggesting the SCCD technology acted as homogenization step. Regards the sensory test, it was not noted differences for all sensory attributes evaluated, although increased sensory scores were noted for all SCCD beverages. Overall, SCCD technology seems an interesting option to be used at the processing of dairy foods, in particular whey grape juices. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the occurrence, counts, and diversity of spore-forming bacteria in three types (full fat, low fat, and flavored full fat) of “requeijão cremoso”. In addition, the growth potential ( δ ) of three prevalent species of spore-forming bacteria was determined in samples stored at three different temperatures. The occurrence of mesophilic aerobic spore-forming bacteria, mesophilic anaerobic spore-forming bacteria and blowing clostridia was around 30%, while only 1.38% of samples was contaminated with psychrotrophic aerobic spore-forming bacteria. The mean counts of psychrotrophic aerobic spore-forming bacteria, mesophilic anaerobic spore-forming bacteria, blowing clostridia and mesophilic aerobic spore-forming bacteria were 0.11 log CFU/g, 0.33 log MPN/g, 0.45 log MPN/g, and 0.46 log CFU/g, respectively. Paenibacillus sanguinis, P. brassicae, Bacillus thuringiensis, B. circulans, B. licheniformis, and B. pumilus were the most prevalent aerobic spore-forming bacteria species. On the other hand, C. sporogenes was the anaerobic mesophilic spore-forming bacteria species identified. P. sanguinis 2301083, B. thuringiensis bt407 and C. sporogenes JCM1416 may grow in full-fat, low-fat, and flavored full-fat “requeijão cremoso”, reaching δ values > 4 throughout the shelf life (>60 days), even when stored at low temperatures such as 4 °C. [ABSTRACT FROM AUTHOR]

This study aimed to model the inactivation of B. nivea and N. fischeri ascospores in pineapple and papaya juices as influenced by temperature (78, 80, 85, 90 and 92 °C) and soluble solids concentration (10, 13, 20, 27 and 30 °Brix). First, a primary model was used to fit the Weibull model to inactivation data obtained from a combination of temperature and soluble solids concentration and to calculate δ (time for the first decimal reduction) and p (shape parameter). Then, a secondary model was used to describe how the inactivation kinetic parameters of these fungi in pineapple and papaya juices varied with the changes in temperature and soluble solids concentration. The shape parameter ( p ) was fixed for each strain and at temperature and soluble solids concentration studied. The results indicated that both linear and quadratic effects of temperature as well as the interaction between temperature and total soluble solids were deemed significant on δ value for both B. nivea and N. fischeri (except for B. nivea in papaya juice). This study contributes to the field by bringing new predictive models describing the influence and interactions of mild temperature conditions and soluble solids contents of fruit juices on the inactivation kinetics of heat-resistant fungi. [ABSTRACT FROM AUTHOR]

In this study, the relative frequency and concentration of patulin (PAT) and ochratoxin A (OTA) in fruit juices and wines collected in Argentina between 2005 and 2013 were determined by high performance liquid chromatography. PAT was detected in 1997 of 5958 samples (ranging from 3.0 to 19,622 μg/L), and 510 samples presented PAT levels above 50 μg/L. The highest incidence of PAT was observed in 2005 (243 of 419 samples) while the lowest was quantified in 2009 (104 of 482 samples). OTA was detected in only 22 of 1401 samples at concentrations ranging from 0.15 to 3.6 μg/L, and the highest incidence was observed in 2007 (8 of 153 samples). The concentration of PAT and OTA in the beverages analyzed was found to be affected by the type of fruit product, fruit commodity and production year. A great amount of data on the incidence of these mycotoxins in these matrixes can be further used in the development and reinforcement of measures to reduce the burden of their presence in juices and wines. This is important since PAT levels above the limit set by regulations were high and fruit juices are quite consumed by children. Although OTA contamination was low, effective ways to safeguard consumer exposure to PAT and OTA and consequently to protect public health are essential and indispensable. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop a predictive model for the growth of L . monocytogenes and Salmonella in the pulp and the outer rind of Canary melons ( Cucumis melo L.) as a function of temperature. The experiments of L . monocytogenes and Salmonella enterica showed that the former can grow in all temperatures tested, from 5 °C to 35 °C, both on the outer rind and in the pulp of melons while the latter did not grow when the outer rind and the pulp of Canary melons were stored at 5 °C. There was no significant difference (p > 0.05) regarding the growth kinetic parameters [growth rate (μ) and lag time (λ)] when the pathogens were inoculated on the outer rind and pulp following storage between 15 and 35 °C. Secondary models (Ratkowsky model) were able to describe the influence of temperature on μ and λ for both microorganisms on the outer rind and pulp of Canary melons. This study adds quantitative data to the literature on the fate of L . monocytogenes and S . enterica in Canary melons and reveal that pulp and the outer rind of this fruit comprise substrates that support the growth of both pathogens in a wide range of storage temperature. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the growth potential (δ) of Salmonella enterica in various parts (peel, stalk, pulp, and tip) of avocado and sugar apple at different maturation stages (green, mature, and ripe) over time. In addition, physicochemical parameters of the fruits were monitored using standard methods. There were statistically significant differences in the growth potential of S. enterica in the peel, stalk, pulp, and tip of avocado and sugar apple at different maturation stages (green, mature, and ripe) over time. Amongst the four parts of the fruits, the highest growth potential (δ up to 4.4 ± 0.01 in ripe custard apple) was obtained in the pulps. Nonetheless, the growth potential varied with the maturation stage and fruit type. For instance, while the pulp of mature sugar apple supported growth on the 4th day (δ = 0.5 ± 0.01) only, the pulp of ripe sugar apple supported the growth of S. enterica throughout post-inoculation storage with δ = 2.4 ± 0.05, 2.7 ± 0.06, 4.2 ± 0.05 and 4.4 ± 0.01 on the 2nd, 4th, 6th and 8th day post inoculation storage, respectively. • Salmonella enterica exhibits potential to grow in two climacteric fruits. • Growth potential of S. enterica differs between the two fruits. • Ripening impacts the GP of S. enterica in both fruits. • Physicochemical changes seem to not relate with the GP of S. enterica. [ABSTRACT FROM AUTHOR]

Flour samples spiked with ochratoxin A (OTA) (3,10 and 20 μg kg–1), zearalenone (ZEA) (75, 100, and 200 μg kg–1), and deoxynivalenol (DON) (500, 750, and 1000 μg kg–1), and combined mycotoxins (OTA, ZEA and DON at 20, 200 and 1000 μg kg–1) were split into two parts, one used immediately for cracker production, and the other kept at −80 °C for 18 h before the manufacture of crackers. The changes in mycotoxin concentrations in the control flour (without any mycotoxins), spiked flour, dough, and cracker samples produced from the normal and frozen flours were assessed using ultra-performance liquid chromatography. The reduction during fermentation ranked as OTA (21.16–25.92%) > DON (18.08–9.29%) > ZEA (0.02–7.01%), while during baking an increase in OTA (22.56–24.96%) and DON (11.80–21.9%) in contrast with a reduction in ZEA (1.07–3.28%) was noted. The thermal process used in the cracker production and the fermentation procedure used in dough preparation caused a significant decrease in the DON and ZEA concentrations in the final cracker products. The freezing of flour can be introduced as a new method to reduce the contamination by mycotoxins of cereal-based products. • Fate of OTA, ZEN, and DON during the production of crackers was studied. • Freezing condition on the concentrations of mycotoxins was investigated. • ZEN was highly stable, while OTA was unstable throughout fermentation stage. • DON decreased significantly during the cracker production. [ABSTRACT FROM AUTHOR]

This study aimed at determining whether Penicillium spp. strains could survive through the heat treatment applied during the processing of frozen chicken nuggets. Firstly, it was found that the conidia of Penicillium were not able to survive the heat shock in phosphate buffer at pH 7.2 in thermal death tubes (TDT) at 80 °C/30 min. Subsequently, each Penicillium strain was inoculated in frozen chicken nuggets, which were subjected to the following treatments: i) only deep frying (frying oil at 195–200 °C), ii) only baking (120–130 °C until the internal temperature reached 70 °C) and iii) deep frying followed by baking (frying oil temperature of 195–200 °C and baking temperature of 120–130 °C, until the internal temperature reached 70 °C). The results indicated that Penicillium polonicum NGT 23/12, Penicillium commune NGT 16/12, Penicillium solitum NGT 30/12 and Penicillium crustosum NGT 51/12 were able to survive after the combined treatment (deep frying followed by baking) when inoculated in chicken nuggets. P. polonicum NGT 23/12 was the most resistant strain to the combined treatment (deep frying and baking), as its population was reduced by 3 log cycles CFU/g, when the internal temperature reached 78 °C after 10 min and 30 s of baking. The present data show that if Penicillium spp. is present in high numbers in raw materials, such as breading flours, it will survive the thermal processing applied during chicken nuggets production. [ABSTRACT FROM AUTHOR]

In this work, all publicly-accessible published findings on Alicyclobacillus acidoterrestris heat resistance in fruit beverages as affected by temperature and pH were compiled. Then, study characteristics (protocols, fruit and variety, °Brix, pH, temperature, heating medium, culture medium, inactivation method, strains, etc.) were extracted from the primary studies, and some of them incorporated to a meta-analysis mixed-effects linear model based on the basic Bigelow equation describing the heat resistance parameters of this bacterium. The model estimated mean D * values (time needed for one log reduction at a temperature of 95 °C and a pH of 3.5) of Alicyclobacillus in beverages of different fruits, two different concentration types, with and without bacteriocins, and with and without clarification. The z T (temperature change needed to cause one log reduction in D -values) estimated by the meta-analysis model were compared to those (‘observed’ z T values) reported in the primary studies, and in all cases they were within the confidence intervals of the model. The model was capable of predicting the heat resistance parameters of Alicyclobacillus in fruit beverages beyond the types available in the meta-analytical data. It is expected that the compilation of the thermal resistance of Alicyclobacillus in fruit beverages, carried out in this study, will be of utility to food quality managers in the determination or validation of the lethality of their current heat treatment processes. [ABSTRACT FROM AUTHOR]

This work aims to determine the mineral composition of Brazilian artisanal cheese (BAC) and classify the cheese types using chemometric techniques. Samples of BAC were analyzed and divided according to their region: Northeast cheeses (Coalho and Manteiga); Midwest cheeses (Caipira); Southeast cheeses (Araxá, Campo das Vertentes , Cerrado , Serra da Canastra and Serro) and South cheeses (Colonial and Serrano). Major (Ca, K, Mg, Na) and trace elements (Cu, Mn, Zn) content were determined by inductively coupled plasma optical emission spectrometer (ICP-OES). Artificial neural network (ANN), K-nearest neighbor (KNN), Random Forest (RF), Support vector machines with the radial kernel (SVM), and Learning Vector Quantization (LVQ) were used as supervised statistical methods to differentiate and classify the cheeses according to the type, and producing region. Coalho cheese showed the highest Ca, Cu, Mn, and Zn content with 91.09 mg g−1, 63.51 μg g−1, 3.29 mg g−1, and 137.51 μg g−1, respectively. Canastra cheese showed the highest K and Na content with 11.68 mg g−1 and 96.98 mg g−1, respectively. Cerrado cheese showed the highest Mg content (7.56 mg g−1). These differences in mineral content are explained by the type of cheese (fresh, ripened), producing region (climate, animal feeding, raw milk), and the technological process of cheese making (salts, metallic instruments). BAC is an essential source of minerals beneficial to health, and its authenticity is paramount for the consumer. RF and SVM classifiers were able to classify the cheese type dataset using the accuracy and Kappa coefficient as the figures of merit (Accuracy= 0.8347 and Kappa= 0.8105, Accuracy=0.8323 and Kappa=0.8078, respectively). For the classification of the production region, all algorithms presented excellent figures of merit. The classification performance can be characterized as outstanding for both cases. Such techniques guarantee the authenticity of Brazilian artisanal cheeses and the Protected Designation of Origin of the cheeses from each region, enhancing the added value of the cheese. • The mineral composition of Brazilian artisanal cheese was determined. • Statistical and chemometrics tools were applied to classify cheese. • Random forest and Support vector machine models with satisfactory results. • Techniques that guarantee the authenticity of artisanal cheeses were developed. [ABSTRACT FROM AUTHOR]

Abstract: The behaviour of Listeria monocytogenes in the fresh coconut water stored at 4 °C, 10 °C and 35 °C was studied. The coconut water was aseptically extracted from green coconuts (Cocos nucifera L.) and samples were inoculated in triplicate with a mixture of 5 strains of L. monocytogenes with a mean population of approximately 3 log10 CFU/mL. The kinetic parameters of the bacteria were estimated from the Baranyi model, and compared with predictions of the Pathogen Modelling Program so as to predict its behaviour in the beverage. The results demonstrated that fresh green coconut water was a beverage propitious for the survival and growth of L. monocytogenes and that refrigeration at 10 °C or 4 °C retarded, but did not inhibit, growth of this bacterium. Temperature abuse at 35 °C considerably reduced the lagtimes. The study shows that L. monocytogenes growth in fresh green coconut water is controlled for several days by storage at low temperature, mainly at 4 °C. Thus, for risk population this product should only be drunk directly from the coconut or despite the sensorial alterations should be consumed pasteurized. [Copyright &y& Elsevier]

This study aimed to determine the growth potential (δ) of L. monocytogenes (CLIST 3974, CLIST 3969, and CLIST 4162) and S. enterica [ S. Typhimurium (ATCC SM 14028), S. Enteritidis (SM 64), and S. Montevideo (SM 129)] in the presence of a pool of lactic acid bacteria (LAB) with antimicrobial activity in Frescal and semi-hard Minas microcheeses. The δ was determined after storing Frescal cheese at 4 and 7 °C for 15 days and the and semi-hard Minas cheese during ripening (22 °C for 22 days). The δ of L. monocytogenes was significantly higher in Frescal Minas cheese with no added LAB (p > 0.05). On the other hand, in semi-hard cheese inoculated with LAB, inactivation of L. monocytogenes was observed. No significant differences were found in the δ of S. enterica in Frescal Minas cheese inoculated with LAB at 4 and 7 °C. S. enterica SM 14028 and SM 129 could grow in semi-hard cheeses non-inoculated with LAB, while when LAB was inoculated, S. enterica was inactivated. The findings of this study indicated that the δ of L. monocytogenes strains was more affected in cheeses inoculated with LAB than the δ of S. enterica. • Selected lactic acid bacteria (LAB) impact the Listeria growth in Minas Cheese. • LAB caused inactivation of L. monocytogenes in semi-hard cheese. • Effects of LAB on S. enterica growth varied with cheese type and strain tested. • LAB influenced the ending pH for all treatments, regardless the cheese type. [ABSTRACT FROM AUTHOR]

This study determined the desiccation resistance of 37 Salmonella strains belonging to 16 serotypes isolated from the soybean meal production chain. Besides, the survival of strains from three Salmonella enterica serovars (S. Typhimurium , S. Schwarzengrund, and S. Havana) on dry- and wet-inoculated soybean meal through storage at 25 °C and 37 °C was evaluated. Desiccation resistance varied within strains of the same serotype and amongst strains of different serotypes. On the other hand, the isolation source did not affect desiccation resistance. The inoculation method did not influence the survival of the three Salmonella enterica strains in soybean meal, but the effects of serovars and temperature were statistically significant (p < 0.05). The Weibull model was fitted to Salmonella survival in this matrix data, with the time for the first decimal reduction (δ) ranging from 21.1 to 50.8 days at 25 °C and from 2.7 to 7.9 days at 37 °C, respectively. The increase in storage temperature led to a decrease in survival regardless of the variability among the three isolates. The ability of Salmonella enterica to resist desiccation and to survive long-term on soybean meal reinforces the need for strategies to control this pathogen in the soybean production chain. • Desiccation resistance of 37 Salmonella isolated from soybean bran was evaluated. • Large differences in desiccation resistance inter- and intra-serotypes were found. • Wet or dry inoculation did not influence the survival of Salmonella in soybean bran. • The time for the first decimal reduction varied from 21.1 to 50.8 days at 25 °C. • The time for the first decimal reduction varied from 2.7 to 7.9 days at 37 °C. [ABSTRACT FROM AUTHOR]

This study assessed the acid-adaptation of pathogenic and non-pathogenic strains of Escherichia coli in orange juice and the microbial resistance to the subsequent UV-C radiation treatment. Nine Shiga toxin-producing E. coli (STEC) and one strain of a non-pathogenic surrogate E. coli were used in this study. Each E. coli strain was inoculated in orange juice, following pre-exposure during 0, 1, 2, and 3 h at 10 °C. Then, the inoculated juices with the ten different strains separately were exposed to 0 and 2 J/cm2 of UV-C radiation. The D value (i.e., the UV-C dose in J/cm2 required to cause a one-log reduction in the target microorganism) was calculated. Further, the resistance coefficient [RC; i.e., the ratio between the D -values for the control condition (D 0h) and each pre-exposure tested time (D 1h, D 2h , D 3h)] were determined. The results indicated that the resistance of E. coli was influenced by the pre-exposure period in the orange juice, with increased resistance to UV-C observed for periods >2 h. Furthermore, the sensitivity of cells to subsequent UV-C treatment was found to be strain-dependent. The results may allow the development of more reliable UV-C radiation processes for orange juice processing aiming the inactivation of pathogenic E. coli. • Adaptation of 10 E. coli strains in orange juice and increased resistance to UV-C • Resistance of E. coli was influenced by pre-incubation period in orange juice (OJ). • Cells exposed >2 h in OJ showed increased resistance to UV-C treatment. • Sensitivity of cells in OJ and to subsequent UV-C treatment was strain-dependent. [ABSTRACT FROM AUTHOR]

In this study, P. fluorescens -infecting phages were isolated, characterized, and evaluated to their potential to control the bacterial counts and, consequently, the proteolytic spoilage of raw milk during cold storage. The UFJF_PfDIW6 and UFJF_PfSW6 phages showed titers of 9.7 and 7.6 log PFU/ml; latent period of 115 and 25 min, and burst size of 145 and 25 PFU/infected cell, respectively. They also were highly specific to the host bacterium, morphologically classified as the Podoviridae family, stable at pH 5 to 11 and were not inactivated at 63 °C or 72 °C for 30 min. These phages found to be effective against P. fluorescens , reducing bacterial count throughout the entire exponential growth phase in broth formulated with milk at both 4 °C and 10 °C. This effect on bacteria growth led to inhibition by at least 2 days in proteases production, delaying the degradation of milk proteins. When applied together in raw milk stored at 4 °C, they reduced the total bacteria, psychrotrophic, and Pseudomonas by 3 log CFU/ml. This study's findings indicate that these phages have a great potential to prevent the growth of Pseudomonas and, consequently, to retard proteolytic spoilage of raw milk during chilled storage. • P.fluorescens phages showed high host specificity and thermal and pH resistance. • UFJF_PfDIW6 and UFJF_PfSW6 phages reduced P. fluorescens in Milk-PBE medium. • The effect of these phages on P. fluorescens led to reduction in casein hydrolysis. • UFJF_PfDIW6 and UFJF_PfSW6 have great potential to prevent spoilage of raw milk. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate technological (acidification, proteolysis, lipolysis, resistance to low pH, NaCl, and bile salts) and biopreservation (antimicrobial activity against foodborne pathogens) features of 1002 LAB by high throughput screening (HTS) methods. The LAB was isolated from 11 types of Brazilian artisanal cheeses (BAC) marketed in the main 5 producing regions. Remarkable intra-species variability in acidification rates have been found, which was most pronounced between isolates from Mina's artisanal cheeses, Caipira and Coalho cheeses. Lacticaseibacillus paracasei and Levilactobacillus brevis showed the fastest acidification rate; however, all isolates showed slower acidification rates than a lactococcal control strain (4.3 × lower). When testing inhibitory effects, > 75% of LAB isolates could inhibit the growth of Staphylococcus aureus ATCC 19095 and Listeria monocytogenes ATCC 7644. Two of these isolates, identified as Lactiplantibacillus plantarum and Lentilactobacillus buchneri , the sterile and neutral supernatants alone, were sufficient to inhibit L. monocytogenes growth. Principal component analysis (PCA) allowed the identification of functional groups based on proteolytic and lipolytic activity, osmotic stress resistance, and inhibition of L. monocytogenes. The type of cheese the isolates were recovered from influenced properties such as anti-listerial compounds and lipolytic enzyme production. The use of HTS and multivariate statistics allowed insights into a diverse set of LAB technological and biopreservation properties. These findings allow a profound knowledge of the heterogeneity of a large set of isolates, which can be further used to design starter cultures with varied and combined properties, such as biopreservation and technological features. Besides that, HTS makes it possible to analyze a vast panel of LAB strains, reducing costs and time within laboratory analysis, while avoiding the loss of information once all LAB are tested at the same time (differently from the traditional labor-intensive approach, in which a few numbers of strains is tested per time). • Lactic acid bacteria (LAB) isolated from 11 types of Brazilian artisanal cheeses. • Biopreservation and technological features of LAB assessed by high-throughput tools. • Multivariate approach grouped LAB based on technological and preservation features. • Inhibitory activity and enzyme production of LAB seemed to be cheese-dependent. • Heterogeneity of large LAB set is key to design starter culture with chosen traits. [ABSTRACT FROM AUTHOR]

The effect of ohmic heating (OH) (50, 55, and 60 °C, 6 V/cm) on the inactivation kinetics (Weibull model) and morphological changes (scanning electron microscopy and flow cytometry) of Salmonella spp. in infant formula (IF) was evaluated. In addition, thermal load indicators (hydroxymethylfurfural and whey protein nitrogen index, HMF, and WPNI) and bioactive compounds (DPPH, total phenolics, ACE, α-amylase, and α-glucosidase inhibitory activities) were also studied. OH presented a more intense inactivation rate than conventional heating, resulting in a reduction of about 5 log CFU per mL at 60 °C in only 2.91 min, being also noted a greater cell membrane deformation, higher formation of bioactive compounds, and lower values for the thermal load parameters. Overall, OH contributed to retaining the nutritional value and improve food safety in IF processing. • Inactivation kinetics and morphological changes of Salmonella spp. in infant formula submitted to ohmic heating. • Intense decay of microorganism counts and greater cell membrane deformation. • Increased formation of bioactive compounds. [ABSTRACT FROM AUTHOR]

• First large centesimal characterization of Brazilian artisanal cheeses (BAC). • BAC production region can be differentiated based on free fatty acid content. • BAC presented healthy atherogenic and thrombogenic indexes. • BAC are good source of proteins. • BAC provide low amount of daily fat intake. A broad survey on fatty acid profile and gross composition of different types of Brazilian artisanal cheeses (BAC; n = 402) produced in North, South, Northeast, Central-West, and Southeast regions of the country was performed. Results suggested that cheeses from North and Northeast regions have a different gross composition and fatty acid profile than the cheeses produced in the other regions. Butter cheese presented a higher fat content and a lower polyunsaturated fatty acid (PUFA) level, with a higher atherogenic index (AI). Marajó cheese presented lower ash and protein content and higher fat content and monounsaturated fatty acid (MUFA) level, with consequent lower AI and thrombogenic index (TI) and higher desired fatty acid (DFA). Linear Discriminant Analysis (LDA) proportionated the cheeses' good discrimination based on geographical origin and free fatty acid composition. [ABSTRACT FROM AUTHOR]

Antimicrobial photodynamic treatment (aPDT) is a promising alternative to conventional thermal inactivation methods. This study aimed to evaluate Bacillus cereus vegetative cells' inactivation and spores by aPDT with new methylene blue (NMB) as photosensitizer (PS) using red light. The efficacy of aPDT was determined initially by minimal inhibitory concentration (MIC) of NMB at different concentrations and fluences. Cluster analysis from the results of MIC grouped B. cereus strains according to their aPDT susceptibility. Then, four strains (B63, B3, 436, and ATCC 14579) were selected for a survival study of aPDT with NMB in three concentrations (5, 50, and 100 μM). The viability of B. cereus vegetative cells and spores was reduced in all tested fluences. The strain ATCC 14579 (vegetative cells and spores) was the most susceptible to aPDT at relatively low fluence (25 J/cm2). The Weibull model presented a good fit for the inactivation data estimating the kinetic parameters δ (first decimal reduction) and p (shape parameter). This study contributes to the knowledge of the behavior of different strains of B. cereus regarding an emerging method of microbial inactivation. The variability of inactivation among strains will allow the development of more reliable processes. • Antimicrobial photodynamic treatment (aPDT) for inactivation of B. cereus is effective. • Cluster analysis grouped strains according to aPDT susceptibility. • Variability among the strains of the same origin was observed. • The Weibull model was able to estimate the inactivation kinetic parameters of aPDT. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the prevalence of spore forming rope-producing microorganisms in different types of flour and to evaluate the potential for spoilage of the isolates through the simulation of the bread manufacturing process. Mesophilic and thermophilic aerobic spore forming bacteria were enumerated in 100 flour samples. Strains isolates were evaluated for their ability to produce amylase and cause rope spoilage in different bread formulations. Amylase-producing strains were identified through 16S rRNA sequencing. The wholemeal flour from industry presented the highest aerobic mesophilic spore forming bacteria counts (3.1 log spores/g). A total of 327 strains were isolated from flours, among which 45 produced amylase. These isolates were identified as Bacillus licheniformis (62%), B. sonorensis (20%) B. cereus (11%), B. pumilus (2%), and Paenibacillus polymyxa (2%). All 45 strains were able to cause spoilage in bread with and without preservatives. The addition of calcium propionate and reduction of water activity and pH were able to prevent the development of rope for 7 days. The development of new formulations can help to assure the microbiological quality and safety of baked products. • Bacillus were isolated from different types of flour. • 45 isolates produced amylase and exhibited potential for rope degradation. • Different bread formulations can inhibit Bacillus growth. • B. licheniformis was the main species isolated from flours. [ABSTRACT FROM AUTHOR]

Fresh cheeses are considered good vehicles for probiotics, and maintenance under refrigeration is essential for preserving their quality and safety. This study's objective was to assess the temperature variability during the commercialization of probiotic cheeses and other fresh cheeses sold in retail stores of different sizes from two regions of Brazil. A statistical analysis comprising retail store size (small, medium, large, extra-large), refrigerated display type (no doors or glass doors), cheese sample position in the refrigerated display (front, middle and back shelves) and cheese type (probiotic, fresh, other cheeses) was performed. The results identified that only 38% of probiotic cheese samples were kept at ≤ 8.0 °C with temperatures ranging from 2.2 to 17.5 °C; considering all cheese samples, the total range extended from −1.4 °C to 17.5 °C. The temperatures exhibited by the exposed cheeses depended on the interaction among the various factors analyzed, and, preferably, glass doors refrigerated displays should be used for storage. The findings of this study provide insights into temperature conditions currently employed in retail stores and can be useful for industries and authorities to reinforce surveillance programs and educational activities for the distribution sector. • There is a wide temperature variation during commercialization of cheeses. • Cheese temperature depends on the cheese location within and on refrigerator type. • Cheese temperature is independent of retail store size and periods of the day. • Temperature variation scenarios should be used for shelf life assessment of cheeses. [ABSTRACT FROM AUTHOR]