Phenotypic, genotypic, and resistome of mesophilic spore-forming bacteria isolated from pasteurized liquid whole egg.

The production of whole-liquid eggs is of significant economic and nutritional importance. This study aimed to assess the phenotypic and genotypic diversity of mesophilic aerobic spore-forming bacteria (n = 200) isolated from pasteurized whole liquid egg and liquid egg yolk. The majority of the isolates were identified as belonging to the genera Bacillus (86 %), followed by Brevibacillus (10 %) and Lysinibacillus (4 %). For the phenotypic characterization, isolates were subjected to various heat shocks, with the most significant reductions observed at 80 °C/30 min and 90 °C/10 min for isolates recovered from raw materials. On the other hand, the decrease was similar for isolates recovered from raw material and final product at 100 °C/5 min and 110 °C/5 min. Genotypic genes related to heat resistance (cdnL, spoVAD, dacB, clpC, dnaK, and yitF/Tn1546) were examined for genotypic characterization. The dnaK gene showed a positive correlation with the highest thermal condition tested (110 °C/5 min), while 100 °C/5 min had the highest number of positively correlated genes (clpC, cdnL, yitF/Tn1546, and spoVAD). Whole Genome Sequencing of four strains revealed genes related to sporulation, structure formation, initiation and regulation, stress response, and DNA repair in vegetative cells. The findings of this study indicate that these mesophilic aerobic spore-forming bacteria may adopt several strategies to persist through the process and reach the final product. As the inactivation of these microorganisms during egg processing is challenging, preventing raw materials contamination and their establishment in processing premises must be reinforced.

Effects of human donor milk on gut barrier function and inflammation: in vitro study of the beneficial properties to the newborn.

Introduction: The gastrointestinal and immune systems of premature infants are not fully developed, rendering them more vulnerable to severe complications like necrotizing enterocolitis. Human milk offers a rich array of bioactive factors that collectively contribute to reducing the incidence of gut infections and inflammatory conditions. When a mother's milk is unavailable, preterm infants are often provided with donor human milk processed in Human Milk Banks. However, it remains uncertain whether pasteurized milk confers the same level of risk reduction as unprocessed milk. This uncertainty may stem from the well-documented adverse effects of heat treatment on milk composition. Yet, our understanding of the comprehensive impact on protective mechanisms is limited. Methods: In this study, we conducted a comparative analysis of the effects of raw versus pasteurized milk and colostrum versus mature milk on cellular functions associated with the gut epithelial barrier and responses to inflammatory stimuli. We utilized THP-1 and HT-29 cell lines, representing monocyte/macrophages and gut epithelial cells, respectively. Results: Our observations revealed that all milk types stimulated epithelial cell proliferation. However, only raw colostrum increased cell migration and interfered with the interaction between E. coli and epithelial cells. Furthermore, the response of epithelial and macrophage cells to lipopolysaccharide (LPS) was enhanced solely by raw colostrum, with a milder effect observed with mature milk. In contrast, both raw and pasteurized milk diminished the LPS induced response in monocytes. Lastly, we examined how milk affected the differentiation of monocytes into macrophages, finding that milk reduced the subsequent inflammatory response of macrophages to LPS. Discussion: Our study sheds light on the impact of human milk on certain mechanisms that potentially account for its protective effects against necrotizing enterocolitis, highlighting the detrimental influence of pasteurization on some of these mechanisms. Our findings emphasize the urgency of developing alternative pasteurization methods to better preserve milk properties. Moreover, identifying the key components critically affected by these protective mechanisms could enable their inclusion in donor milk or formula, thereby enhancing immunological benefits for vulnerable newborns.

[Effect of pasteurization and freezing on the content of IgA1 and IgA2 subtypes in breast milk]. / Reducción del contenido de IgA1 e IgA2 en la leche materna por efecto de la pasteurización y congelación.

OBJECTIVE: To determine the effect of pasteurization and freezing on the content of IgA1 and IgA2 in breast milk. METHODS: Observational, retrospective study, carried out in women who had been breastfeeding their newborn for more than 30 days, and could donate 50 mL of milk. The concentration of IgA1 and IgA2 was determined by turbidimetry, before and after being subjected to pasteurization and freezing, every 15 days for 2 months. Freezing was at -20°C. A total IgA content of 1598.5 mg/dL was found. RESULTS: 10 breast milk donors were selected. The initial concentration of IgA1 and IA2 was 651 and 945.7 mg/dL, respectively; At the end of the freezing times, the content of both immunoglobulins decreased: IgA1 of 74% and IgA2 of 86%. After the treatments, the immunoglobulin content decreased dramatically, with a significant difference of p < 0.05. CONCLUSIONS: Pasteurization and freezing significantly affect the content of IgA1 and IgA in breast milk; therefore, breast-feeding remains the best way to offer full immunological protection to the infant.

OBJECTIVO: Determinar el efecto de la pasteurización y congelación en el contenido de IgA1 e IgA2 en la leche materna. MÉTODOS: Estudio observacional y retrospectivo, llevado a cabo en mujeres que tuvieran más de 30 días de ofrecer lactancia a su neonato, y pudieran donar 50 mL de leche. Se determinó la concentración de IgA1 e IgA2 mediante turbidimetría, antes y después de someterse a pasteurización y congelación, cada 15 días durante 2 meses. La congelación fue a ­20°C. Se encontró un contenido total de IgA de 1598,5 mg/dL. RESULTADOS: Se seleccionaron 10 donantes de leche materna. La concentración inicial de IgA1 e IA2 fue de 651 y 945.7 mg/dL, respectivamente; al finalizar los tiempos de congelación disminuyó el contenido de ambas inmunoglobulinas: IgA1 del 74% e IgA2 del 86%. Después de los tratamientos, el contenido de inmunoglobulinas disminuyó de forma contundente, con diferencia significativa de p < 0.05. CONCLUSIONES: La pasteurización y la congelación afectan de manera importante el contenido de IgA1 e IgA en la leche materna; por tanto, la alimentación al seno materno sigue siendo la mejor forma de ofrecer toda protección inmunológica al lactante.

Ultrasonication and thermosonication applied in the processing of jalapeno pepper (Capsicum annuum var. annuum) sauce.

Ultrasonication is one of the non-thermal physical methods that can be used on foods and when used in synergy with temperature (thermosonication), this technique proves to be more effective, thus reducing the duration and intensity of heat treatment and the consequent damage to the foods. This work aimed to use the technique of ultrasonication and thermosonication in the processing of jalapeno pepper sauces in comparison with pasteurization. Two types of sauces were produced, one with pre-cooking (a) and the other without cooking (b), and the influence of time and temperature was analyzed by applying ultrasonication and thermosonication. Times of 15 and 30 min and temperatures of 25 and 65 °C were used. Both treatments stood out for their effectiveness when compared to the traditional method (pasteurization 65 °C and 30 min). The results demonstrate that, in general, the sauces are good sources of phenolic compounds (141.83 ± 0.10 mg gallic acid equivalent/100 g), flavonoids (50.40 ± 0.30 mg quercetin equivalent/100 g) and carotenoids (2.39 ± 0.07 mg ß-carotene/100 g). The sauces had an increase in carotenoids by about 25% (thermosonicated at 15 and 30 min and pre-cooked) and in antioxidant activity (ferric reducing antioxidant power) with about 12% and 13% (thermosonicated at 30 min with and without cooking, respectively) in relation to control (pasteurization). On comparing thermosonication with ultrasound process total phenolics had improved by around 14% and flavonoids by 55%. At the first time, capsantin, capsaicin, dihydrocapsaicin, and nordihydrocapsaicin were identified by ultra-high performance liquid chromatography-MS/MS (UHPLC-MS/MS). Finally, as both treatments demonstrate efficiency (thermosonication at 15 and 30 min), the use of 15 min is indicated as feasible by the reduced process time and in preventing the loss of bioactive compounds in the sauces when compared to the pasteurization treatment.

High-pressure pulses for Aspergillus niger spore inactivation in a model pharmaceutical lipid emulsion.

High hydrostatic pressure (HHP) is a non-thermal process widely used in the food industry to reduce microbial populations. However, rarely its effect has been assessed in products with high oil content. This study evaluated the efficacy of HHP (200, 250, and 300 MPa) at different temperatures (25, 35, and 45 °C) by cycles (1, 2, or 3) of 10 min in the inactivation of Aspergillus niger spores in a lipid emulsion. After treatments at 300 MPa for 1 cycle at 35 or 45 °C, no surviving spores were recovered. All treatments were modeled by the linear and Weibull models. The presence of shoulders and tails in the treatments at 300 MPa at 35 or 45 °C resulted in sigmoidal curves which cannot be described by the linear model, hence the Weibull + Tail, Shoulder + Log-lin + Tail, and double Weibull models were evaluated to elucidate the inactivation kinetics. The tailing formation could be related to the presence of resistance subpopulations. The double Weibull model showed better goodness of fit (RMSE <0.2) to describe the inactivation kinetics of the treatments with the higher spore reductions. HHP at 200-300 MPa and 25 °C did not reduce the Aspergillus niger spores. The combined HHP and mild temperatures (35-45 °C) favored fungal spore inactivation. Spore inactivation in lipid emulsions by HHP did not follow a linear inactivation. HHP at mild temperatures is an alternative to the thermal process in lipid emulsions.

Identification and evaluation of thermotolerance of yeasts from milk in natura exposed to high temperature and slow and fast pasteurization.

Milk is considered one of the basic raw materials of animal origin; it must present hygienic quality and physical-chemical properties suitable for processing and human consumption. Thus, the ingestion of milk in natura when not properly treated can be characterized as an opportunistic route of transmission of possible microbial pathogens, which can offer risks to public health. The present study aimed the yeast identification, to analyze the thermo-resistance of yeasts isolated from fresh milk, and to trace the susceptibility profile of the isolates to antifungal agents. For this, 23 samples of fresh milk type B, collected by manual or mechanical milking, were stored in collective refrigeration tanks of farms located in the Metropolitan Region of Natal and nearby, State of Rio Grande do Norte (RN), Brazil. Twenty samples of fresh milk commercially traded in the city of Ceará-Mirim RN were also analyzed. The yeasts were quantified by count of colony-forming units (CFU). All isolated species were treated by slow pasteurization (62-64 °C for 30 min) and fast (72-75 °C for 20 s), as well as by boiling (100 °C). Fifty yeast strains were obtained, and the species were identified as Candida tropicalis (28%), Candida parapsilosis (14%), Candida albicans (12%), Candida glabrata (10%), Candida krusei (10%), Kluyveromyces marxianus (10%), Candida guilliermondii (8%), Candida rugosa (2%), Candida orthopsilosis (2%), Pichia manshurica (2%), and Kodamaea ohmeri (2%). Five isolates showed resistance to the antifungal agents tested. Among all the isolates submitted to heat treatment, 80% were resistant to fast pasteurization and 60% to boiling, but none of them resisted the slow pasteurization. The milk collected through mechanical milking and stored in collective cooling tanks, presented higher rates of yeast contamination, compared to milk samples collected by manual milking and kept under the same storage conditions.

Pasteurized milk quality in Brazil: a cross-sectional study over five years.

This research communication delineates the quality of pasteurized cow milk sold in Brazil from 2015 to 2020. A cross-sectional study was performed gathering 1749 samples, which were evaluated for microbiological and physicochemical parameters, including Salmonella spp., total and thermotolerant coliforms, freezing point, alkaline phosphatase and lactoperoxidase. The proportion of compliant and non-compliant samples was compared through the years and jurisdiction of the inspection services. Interactions between the design and response variables were assessed by log-linear analysis. Overall, a considerable non-conformity rate (12%) was found for at least one microbiological or physicochemical parameter. Post-pasteurization contamination by coliforms was the major challenge for dairy industries. Notably, the non-compliance rate for freezing point increased during the SARS-CoV-2 pandemic. In addition, the ability to comply was linked to the type of inspection service. Thus, it is suggested that the SARS-CoV-2 pandemic is affecting the dairy industries in Brazil, and we strengthen the need for more studies monitoring the quality of milk over the years, which could assist industries and regulatory agencies to ensure the compliance of pasteurized milk.

Gamma radiation and pasteurization on anthocyanin stability and antioxidant capacity of jussara pulp (Euterpe edulis) during storage / Efeito da radiação gama e pasteurização na estabilidade de antocianinas e na capacidade antioxidante da polpa jussara (Euterpe edulis) durante o armazenamento

ABSTRACT: The effects of gamma irradiation and pasteurization on the stability of anthocyanins and antioxidant capacity during storage of jussara pulp were investigated. Jussara pulp was divided into 6 portions: control (no treatment), irradiated pulp (2, 4, 6, 8 kGy) and pasteurized pulp (92 ºC/ 1 minute). Portions were stored at 4ºC for 60 days. The phenolic extract was prepared with a solution of methanol/water/formic acid. The following analyses were performed every 15 days: contents of total phenolic compounds by Folin-Ciocauteau, cyanidin-3-glycoside and cyanidin-3-rutiniside by HPLC and antioxidant capacity (ABTS and DPPH). Total phenolics and anthocyanins decreased with the increasing irradiation dose and storage time. Pasteurization did not affect the phenolic concentration immediately after processing. However, the contents of TPC and cyanidin-3-rutiniside were reduced during storage of the pasteurized pulp. No processed samples presented characteristics similar to the control at the end of storage.

RESUMO: Os efeitos da radiação gama e pasteurização na estabilidade das antocianinas e na capacidade antioxidante durante o armazenamento da polpa de jussara foram avaliados. A polpa de jussara foi dividida em diferentes tratamentos: controle (sem tratamento), polpa irradiada (2, 4, 6, 8 kGy) e pasteurizada polpa (92 ºC / 1 minuto). Os tratamentos foram armazenados a 4ºC por 60 dias. O extrato fenólico foi preparado com uma solução de metanol / água / ácido fórmico. As seguintes análises foram realizadas a cada 15 dias: teores de compostos fenólicos totais por Folin-Ciocauteau, cianidina 51 3-glicosídeo e cianidina-3-rutinisida por HPLC e capacidade antioxidante (ABTS e DPPH). Os fenólicos totais e as antocianinas diminuíram com o aumento da dose de irradiação e do tempo de armazenamento. A pasteurização não afetou a concentração fenólica imediatamente após o processamento. No entanto, os teores de TPC e cianidina-3-rutinisida foram reduzidos durante o armazenamento da polpa pasteurizada. Nenhuma amostra processada apresentou características semelhantes ao controle ao final do armazenamento.

Gamma radiation and pasteurization on anthocyanin stability and antioxidant capacity of jussara pulp (Euterpe edulis) during storage / Efeito da radiação gama e pasteurização na estabilidade de antocianinas e na capacidade antioxidante da polpa jussara (Euterpe edulis) durante o armazenamento

The effects of gamma irradiation and pasteurization on the stability of anthocyanins and antioxidant capacity during storage of jussara pulp were investigated. Jussara pulp was divided into 6 portions: control (no treatment), irradiated pulp (2, 4, 6, 8 kGy) and pasteurized pulp (92 ºC/ 1 minute). Portions were stored at 4ºC for 60 days. The phenolic extract was prepared with a solution of methanol/water/formic acid. The following analyses were performed every 15 days: contents of total phenolic compounds by Folin-Ciocauteau, cyanidin-3-glycoside and cyanidin-3-rutiniside by HPLC and antioxidant capacity (ABTS and DPPH). Total phenolics and anthocyanins decreased with the increasing irradiation dose and storage time. Pasteurization did not affect the phenolic concentration immediately after processing. However, the contents of TPC and cyanidin-3-rutiniside were reduced during storage of the pasteurized pulp. No processed samples presented characteristics similar to the control at the end of storage.

Os efeitos da radiação gama e pasteurização na estabilidade das antocianinas e na capacidade antioxidante durante o armazenamento da polpa de jussara foram avaliados. A polpa de jussara foi dividida em diferentes tratamentos: controle (sem tratamento), polpa irradiada (2, 4, 6, 8 kGy) e pasteurizada polpa (92 ºC / 1 minuto). Os tratamentos foram armazenados a 4ºC por 60 dias. O extrato fenólico foi preparado com uma solução de metanol / água / ácido fórmico. As seguintes análises foram realizadas a cada 15 dias: teores de compostos fenólicos totais por Folin-Ciocauteau, cianidina 51 3-glicosídeo e cianidina-3-rutinisida por HPLC e capacidade antioxidante (ABTS e DPPH). Os fenólicos totais e as antocianinas diminuíram com o aumento da dose de irradiação e do tempo de armazenamento. A pasteurização não afetou a concentração fenólica imediatamente após o processamento. No entanto, os teores de TPC e cianidina-3-rutinisida foram reduzidos durante o armazenamento da polpa pasteurizada. Nenhuma amostra processada apresentou características semelhantes ao controle ao final do armazenamento.

Spray-Dried Infant Formula Emulsion Stability as Affected by Pre-Heat Treatment and Total Solids Content of the Feed.

Pre-spray-drying processing may affect stability after reconstitution of emulsion-based powders, such as infant formulas. This study aimed to evaluate the effects of pasteurization temperature and total solids (TS) of the feed on the stability of the emulsions obtained from the reconstituted powders. Four infant formula powders (50%-75 °C, 50%-100 °C, 60%-75 °C, and 60%-100 °C) were produced at pilot scale, from emulsions with 50 or 60% TS pasteurized at 75 or 100 °C for 18 s. Both the emulsion feeds and the emulsions from the reconstituted powders (12.5% TS) were analyzed. The results showed that feeds with 60% TS were flocculated, as indicated by the large particle size and viscosity and the pseudoplastic behavior. Light microscopy revealed that, during spray drying, the flocs were disrupted in 60%-100 °C, while the 60%-75 °C emulsion remained flocculated, reducing its stability post-reconstitution. Although all four emulsions were mainly stabilized by caseins, the presence of ß-lactoglobulin was also detected at the oil-water interface, in native state in the formulas preheated at 75 °C and aggregated in the formulas preheated at 100 °C. In conclusion, both the degree of whey protein denaturation (resulting from pasteurization) and the TS of the concentrates during infant formula production affected the emulsion stability of the reconstituted powders.

What are the challenges for ohmic heating in the food industry? Insights of a bibliometric analysis.

The trends related to ohmic heating technology in food processing were evaluated using bibliometric analysis based on the scientific literature published in the last decade. Publications from Turkey, Brazil, and Iran represent 32% of all publications. Most studies have targeted the definition of the best combinations of operational parameters for application in different food matrices and their possible effects on the food properties. In addition, a tendency to use ohmic heating as an alternative technology for pasteurization was observed. Future studies should develop mathematical models that evaluate process parameters and food characteristics in the inactivation of microorganisms and enzymes and maintenance of bioactive compounds, the study of the non-thermal effect of electromagnetic waves on the food quality, the evaluation of the processing conditions and food physicochemical properties in the electrode corrosion and migration of metal ions to the treated food, and improvements of homogeneity during processing. This study was the first to perform a bibliometric analysis based on scientific literature concerning ohmic heating in food processing and presented the challenges, future trends, and evolution of scientific research.

The Importance of Heating Unit Operations in the Food Industry to Obtain Safe and High-Quality Products.

Civilization has begun around 3,500 BCE in Mesopotamia and the realization by people that they could manipulate food to preserve it, through sun drying, fermentation, freezing in the snow, or cooking by fire, was an important factor for the nomadic humans to start settling. Food by nature is subject to spoilage and the application of any kind of preservation method enables storage and weighted consumption. Throughout human history, many techniques have been developed and improved such as heat treatment, drying, freezing, extraction, mixing and the use of preservatives, among others. In the food industry of the modern world, each technique is implemented through sequential steps, known as unit operations. This opinion paper presents an overview of the main heating unit operations used in the food industry, highlighting their benefits to converting raw materials into palatable products with high quality and safe for consumption. Examples are presented to illustrate how several food products available in the market were submitted only to physical transformations based on scientific knowledge. However, there is a range of intensity in physical processing and the applied energy level depends on the nature of the food, target microorganism, storage conditions, type of packaging, and desired shelf-life. The importance of food safety is stressed since processed foods have been criticized for confusion between nutritious values and processing steps. There are still many challenges to the food industry to design the process in optimal conditions for food quality and with less environmental impacts and novel thermal and non-thermal technologies have been studied and implemented.

Effects of Bulk Tank Milk, Waste Milk, and Pasteurized Waste Milk on the Intake, Ruminal Parameters, Blood Parameters, Health, and Performance of Dairy Calves.

The aim of this study was to evaluate the effects of bulk tank milk (BTM), WM, and PWM on the intake, ruminal parameters, blood parameters, health, and performance of dairy calves. Forty-five male crossbred dairy calves (Gyr × Holstein) were used. On their fourth day of age, animals were grouped according to body weight, serum protein levels, and genetic composition. Three treatments were assessed: BTM (n = 15), WM from cows in antibiotic treatment (n = 15), and PWM via high-temperature, short-time pasteurization (72-74 °C for 16 s) (n = 15). During the experimental period (from 4 to 60 d of age), animals were fed 6 L of milk/d, divided into two equal meals. Water and concentrate were provided ad libitum. Daily measurements were made for milk, concentrate, and water intakes, as well as for fecal and respiratory scores. Rumen fluid and blood were sampled weekly. The following parameters were evaluated: volatile fatty acids (VFAs), pH and ammonia-N in rumen fluid, and ß-hydroxybutyrate (BHB) and glucose in blood. Animals were weighed at birth, 4 d of age, and weekly up to 60 d of age. At the end of the experimental period (60 ± 1 d), all animals were euthanized for pulmonary evaluation. The randomized complete design with an interaction between treatment and week was the experimental method of choice for testing the hypothesis of the treatment's effect on all evaluated outcomes. Animals in the BTM treatment had higher milk dry matter intake (DMI), followed by WM and PWM calves. Concentrate DMI was lower for BTM in comparison to WM and PWM calves. However, total DMI showed no significant differences between treatments. The rumen fluid from calves receiving PWM had higher concentrations of acetate and propionate than that of BTM and WM animals. No differences were observed between treatments for blood glucose and BHB concentrations. Health parameters (fecal and respiratory scores) and pneumonia occurrence showed no significant difference between treatments. No differences were observed for average daily gain (ADG) or body growth. Feeding WM and PWM did not show significant negative effects on the intake, ruminal parameters, blood parameters, health, or performance of dairy calves.

[Mycobacterium bovis infection in an adolescent with prolonged febrile syndrome]. / Infección por Mycobacterium bovis en una adolescente con síndrome febril prolongado.

Bovine tuberculosis is an infectious, zoonotic disease, caused by Mycobacterium bovis. The bovine is the primary host. Other species can be infected (pigs, goats, horses, etc). Man can be infected by air (lung disease), clinically indistinguishable from that produced by Mycobacterium tuberculosis or by oral or cutaneous route (extrapulmonary forms: digestive, lymph node, skin). Contagion has been mainly related to contact with livestock and the consumption of unpasteurized dairy products. It was also reported the possible contagion between people. It is described the case of an adolescent patient, from the province of Buenos Aires, with prolonged febrile syndrome and abdominal lymph node conglomerate, with a history of ingestion of unpasteurized milk. We consider the importance of warning about the correct processing of food, especially at this time when new food trends (homemade dairy intake or bought at informal fairs) could put the health of the population at risk.

La tuberculosis bovina es una zoonosis causada por Mycobacterium bovis. El bovino es el huésped primario. Otras especies pueden ser infectadas (cerdos, cabras y caballos, entre otras). En el ser humano, el contagio puede ser por vía aérea (enfermedad pulmonar), clínicamente indistinguible de la producida por Mycobacterium tuberculosis, o por vía oral o cutánea, (formas extrapulmonares: digestiva, ganglionar, cutánea). Su contagio se ha relacionado principalmente al contacto con el ganado y al consumo de lácteos sin pasteurizar. También se notificó el posible contagio interpersonal. Se describe el caso de una paciente adolescente, proveniente de la provincia de Buenos Aires, con síndrome febril prolongado y conglomerado ganglionar abdominal, con antecedente de ingestión de leche no pasteurizada. Es fundamental alertar acerca de la importancia del procesamiento correcto de los alimentos, sobre todo en esta época en la que las nuevas tendencias alimentarias (ingestión de lácteos caseros o comprados en ferias informales) pueden poner en riesgo la salud.

Infección por Mycobacterium bovis en una adolescente con síndrome febril prolongado / Mycobacterium bovis infection in an adolescent with prolonged febrile syndrome

La tuberculosis bovina es una zoonosis causada por Mycobacterium bovis. El bovino es el huésped primario. Otras especies pueden ser infectadas (cerdos, cabras y caballos, entre otras). En el ser humano, el contagio puede ser por vía aérea (enfermedad pulmonar), clínicamente indistinguible de la producida por Mycobacterium tuberculosis, o por vía oral o cutánea, (formas extrapulmonares: digestiva, ganglionar, cutánea). Su contagio se ha relacionado principalmente al contacto con el ganado y al consumo de lácteos sin pasteurizar. También se notificó el posible contagio interpersonal.Se describe el caso de una paciente adolescente, proveniente de la provincia de Buenos Aires, con síndrome febril prolongado y conglomerado ganglionar abdominal, con antecedente de ingestión de leche no pasteurizada. Es fundamental alertar acerca de la importancia del procesamiento correcto de los alimentos, sobre todo en esta época en la que las nuevas tendencias alimentarias (ingestión de lácteos caseros o comprados en ferias informales) pueden poner en riesgo la salud.

Bovine tuberculosis is an infectious, zoonotic disease, caused by Mycobacterium bovis. The bovine is the primary host. Other species can be infected (pigs, goats, horses, etc). Man can be infected by air (lung disease), clinically indistinguishable from that produced by Mycobacterium tuberculosis or by oral or cutaneous route (extrapulmonary forms: digestive, lymph node, skin). Contagion has been mainly related to contact with livestock and the consumption of unpasteurized dairy products. It was also reported the possible contagion between people. It is described the case of an adolescent patient, from the province of Buenos Aires, with prolonged febrile syndrome and abdominal lymph node conglomerate, with a history of ingestion of unpasteurized milk. We consider the importance of warning about the correct processing of food, especially at this time when new food trends (homemade dairy intake or bought at informal fairs) could put the health of the population at risk.

Effect of microwave-assisted processing on polyphenol oxidase and peroxidase inactivation kinetics of açai-berry (Euterpe oleracea) pulp.

Microwave heating has been considered a promising technology for continuous flow thermal processing of fluid foods due to better retention of quality. Considering the importance of açai-berry pulp and its perishability, the inactivation kinetics of peroxidase (POD) and polyphenol oxidase (PPO) were investigated under conventional and microwave heating. First-order two-component model was well fitted to the data, indicating the presence of at least two fractions with different resistances. POD was more thermally resistant (90% inactivation for 40 s at 89 °C) and could be considered as a processing target. Inactivation curves dependency on heating technology suggests specific effects of microwaves on the protein structure. Additionally, the dielectric properties of açai-berry pulp were evaluated at 915 and 2,450 MHz for temperatures up to 120 °C. Power penetration depth dropped with temperature at 915 MHz (from 29 to 11 mm), but was less affected at 2,450 MHz (between 8 and 11 mm).

Inactivation of polyphenol oxidase by microwave and conventional heating: Investigation of thermal and non-thermal effects of focused microwaves.

Emerging technologies, such as focused microwave heating of liquid foods, have been studied to reduce quality losses due to the high temperatures of conventional processing. Besides faster heating, microwaves can also have non-thermal effects on inactivation; however, this is a controversial issue. The objective of this study was to compare conventional and focused microwave heating under similar conditions for the inactivation of two polyphenol oxidases (PPOs): mushroom tyrosinase in buffer and the PPO present in coconut water. Small samples under stirring were treated at temperatures between 50 and 90 °C and three kinetic models were adjusted considering the whole time-temperature history. The Weibull model could best describe inactivation in both heating processes, which was more effective with microwave heating for temperatures over 70 °C. Validation runs show that the model can satisfactorily describe the PPO inactivation. This study contributes for the design of liquid food pasteurization by focused microwave technology.

Dielectric properties of Mexican sauces for microwave-assisted pasteurization process.

The dielectric properties and specifically the complex relative permittivity of foods are key elements for the design of pasteurization processes with high frequency electromagnetic waves. Mexican sauces are recognized worldwide for their flavor and nutritional properties. In this work, the complex permittivity of four of the most representative sauces of Mexican cuisine (chipotle chili, habanero chili, red and green sauce) is presented. The permittivity was measured with the open coaxial probe method at temperatures of 25, 40, 55, 70, 85 °C and in the frequency range of 500 MHz to 6 GHz. Additionally, moisture content, specific heat, viscosity, water activity, density and electrical conductivity are reported, these last three at 25 °C. Dielectric properties were affected by the sauce formulation. The loss factor of each sauce sample at any temperature presents significant changes in relation to the frequency. At 915 and 2,450 MHz, d ε ' ' d T > 0 , which would cause a thermal runaway effect or the uncontrolled rise in temperature in the sauces during the microwave pasteurization. At 5,800 MHz, d ε ' ' d T < 0 , which would give better control for microwave heating than at 915 and 2,450 MHz. At 915 MHz, the loss factor of all sauces is higher than at 2,450 and 5,800 MHz, therefore, more rapid heating can be produced. Moreover, at 915 MHz, microwaves exhibit higher penetration depth than at 2,450 and 5,800 MHz; therefore, at 915 MHz, the greatest uniform microwave dielectric heating would be achieved. Thus, 915 MHz is the frequency recommended for the studied sauces pasteurization. PRACTICAL APPLICATION: This work provides the dielectric properties of Mexican sauces at different temperatures and their penetration depths in the microwave range, which are key information for further microwave-assisted pasteurization process and for getting safer sauces for consumers. Moreover, this research supplies suggestions about what frequency for ISM (Industrial, Scientific and Medical) applications is the best for microwave-assisted pasteurization according to the penetration depth of the electromagnetic wave in the sauces and microwave dielectric heating speed of the sauces.

Using extended Bigelow meta-regressions for modelling the effects of temperature, pH, °Brix on the inactivation of heat resistant moulds.

The management of Heat Resistant Moulds (HRMs) is considered a great challenge for the juice fruit industry. Neosartorya, Byssochlamys and Talaromyces are three out of the main genera isolated from fruit juices that show great resistance to heat treatments. Several inactivation parameters can be found in the literature, however all of them were carried out in specific food matrices and using diverse inactivation methods. Thus, this meta-analysis study synthesizes the thermal resistance parameters of the three HRMs by adjusting extended Bigelow-based meta-regression models to data on inactivation experiments conducted in different liquid media. The meta-analytical data, extracted from publications between 1969 and 2017, was composed of decimal reduction time (D), inactivation method, temperature of inactivation, pH, °Brix, age of spores, and type of medium (model, juice, concentrates). Pooled D* values (D at 90 °C, pH 3.5 and 12° Brix) were estimated for B. fulva (1.95 min; 95% CI: 1.21-3.11 min), Talaromyces (4.03 min; 95% CI: 3.43-4.74 min), Neosartorya (0.5.35 min; 95% CI: 4.10-7.08 min), and B. nivea (10.32 min; 95% CI: 5.81-18.4 min). It was found that increasing the soluble solids in concentrates tends to cause a lower decrease in the heat resistance of Neosartorya and Talaromyces than increasing the soluble solids in model liquid or juices (p = 0.001; 0.012). In general, the screw-capped tubes and three neck round inactivation methods render higher D* values (p < 0.05) than the thermal death tubes, the polyethylene bag and the capillary methods. Spores of Talaromyces (overall zpH = 7.56; 95% CI: 5.13-13.5) and Neosartorya (overall zpH = 7.07; 95% CI: 5.04-10.8) appear to be more thermal sensitive to a decrease in medium pH than spores of Byssochlamys (overall zpH = 4.34; 95% CI: 3.20-6.73). The meta-regression models presented in this study can be valuable for estimating pooled inactivation kinetic parameters to be used by the fruit juice industry in the management of thermal processes and in the determination of shelf-life.

Effect of pasteurization on the antioxidant and oxidant properties of human milk / Efeito da pasteurização nas propriedades antioxidantes e oxidantes do leite humano

ABSTRACT Objective: To evaluate the effect of pasteurization on antioxidant and oxidant properties of human milk. Methods: 42 samples of milk before and after pasteurisation were used to evaluate the antioxidant activity by the ferric reducing capacity and by scavenging the 2,2'-azino-bis 3-ethylbenzthiazoline-6-sulfonic acid radical. Lipid peroxidation was estimated by the concentration of malondialdehyde product using the thiobarbituric acid reactive substances assay and by the evaluation of advanced oxidation protein products. Results: No significant difference was observed in fresh human milk and after pasteurization in relation to antioxidant properties determined by the ferric reducing capacity (50.0±3.4% and 48.8±3.0%, respectively) and by scavenging the 2,2'-azino-bis 3-ethylbenzthiazoline-6-sulfonic acid radical (28.9±1.5% and 31.2±1.3%, respectively). The results of malondialdehyde (62.6±4.1 and 64.3±3.6 µM/mg) and protein oxidation products (59.4±3.4 and 54.2±3.8 µM/L) of fresh and pasteurized milk, respectively, did not exhibited any significant difference. Conclusions: This data showed that human milk has an important antioxidant activity and that the pasteurizing process does not influence the antioxidant capacity, avoiding the peroxidation of breast milk lipids and the formation of advanced protein oxidation products.

RESUMO Objetivo: Avaliar o efeito da pasteurização nas propriedades antioxidantes e oxidantes do leite humano. Métodos: Foram utilizadas 42 amostras de leite cru e após a pasteurização, para avaliação da atividade antioxidante pelos métodos da capacidade redutora do ferro e sequestro dos radicais derivados do ácido 2,2'-azino-bis (3-etilbenzotiazolina-6-sulfônico). A peroxidação lipídica (PL) foi estimada pela determinação das substâncias reativas ao ácido tiobarbitúrico e pela avaliação dos produtos proteicos de oxidação avançada. Resultados: Não se observou diferença significante no leite humano cru nem após a pasteurização em relação às propriedades antioxidantes determinadas pelo método da redução do ferro (50,0±3,4% e 48,8±3,0%, respectivamente) e pelo sequestro dos radicais derivados do ácido 2,2'-azino-bis (3-etilbenzotiazolina-6-sulfônico) (28,9±1,5% e 31,2±1,3%, respectivamente). Os resultados médios de malondialdeído [MDA] (62,6±4,1 e 64,3±3,6 µM/mg) e produtos de oxidação proteica (59,4±3,4 e 54,2±3,8 µM/L) entre os grupos leite fresco e leite pasteurizado, respectivamente, não evidenciaram diferença significante. Conclusões: Os dados demonstraram que o leite humano possui importante atividade antioxidante e que o processo de pasteurização não interfere nessa propriedade, evitando assim a peroxidação dos lipídios e a formação de produtos avançados de oxidação proteica.