Este estudo visou analisar a qualidade microbiológica do leite humano cru recebido em um banco de leite humano (BLH), quantificando os microrganismos aeróbios mesófilos, Staphylococcus coagulase positivos (ECP), coliformes totais e Escherichia coli. Foram realizadas análises microbiológicas em 60 amostras de leite humano cru recebidas no BLH e os resultados foram os seguintes: o microrganismo E. coli foi positivo em 50% das amostras analisadas, os coliformes totais em 75% delas, o ECP em 46,66% e em 96,66% do total das amostras foram detectados microrganismos aeróbios mesófilos. Das amostras analisadas, a população de E. coli foi positiva em 93,33% (28 amostras) com uma variação entre 1 e 99 NMP/mL; 3,33% (1 amostra) entre 104 e 9,9 x 104 NMP/mL; 3,33% (1 amostra) entre 105 e 9,9 x105 NMP/mL. A população de coliformes totais que foi positiva em 57,77% (26 amostras) das amostras analisadas ficou entre 1 e 99 NMP/mL; 24,4% (11 amostras) ficaram entre 102 e 9,9x102 NMP/mL; 2,22% (1 amostra) entre 103 e 9,9x103 NMP/mL; 8,88% (4 amostras) entre 104 e 9,9x104 NMP/mL; 4,44% (2 amostras) entre 105 e 9,9x105 NMP/mL; 2,22% (1 amostra) entre 106 e 9,9x106 NMP/mL. Os microrganismos aeróbios mesófilos apresentaram-se na quase totalidade das amostras, sendo que 17,24% (10 amostras) variaram de 1 a 99 UFC/mL; 17,24% (10 amostras) entre 102 e 9,9x102 UFC/mL; 10,34% (6 amostras) ficaram entre 103 e 9,9 x 103 UFC/mL; 25,86% (15 amostras) entre 104 e 9,9 x104 UFC/mL; 17,24% (10 amostras) entre 105 e 9,9 x 105 UFC/mL; 10,34% (6 amostras) entre 106 e 9,9x106 UFC/mL e 1,72% (1 amostra) entre 107 e 9,9x107 UFC/mL. Porém, 3,33% (2 amostras) apresentaram-se negativas. Do total de amostras analisadas, o grupo dos microrganismos ECP apresentouse em 78,57% (22 amostras) com variação entre 1 e 99 UFC/mL; em 3,57% (1 amostra) entre 102 e 9,9x102 UFC/mL; 10,71% (3 amostras) entre 103 e 9,9x103 UFC/mL e 7,14% (2 amostras) entre 104 e 9,9 x 104 UFC/mL. / This paper aimed to analyze the microbiological quality of the raw human milk which is received in a human milk bank (HMB) by quantifying the aerobic mesophiles, Staphylococcus aureus (SCP), total coliforms and Escherichia coli. Sixty (60) samples of raw human milk received in HMB were microbiologic analyzed and the results were as follows: the E. coli microorganism was positive in 50% of the analyzed samples, the total coliforms were in 75% of them, the ECP in 46,6% and in 96,6% of the total amount of samples aerobic mesophiles microorganisms were detected. From the total analyzed samples, the population of E. coli was positive in 93,33% (28 samples) with a variation between 1 and 99 NMP/mL; 3,33% (1 sample) was between 104 and 9,9x104 NMP/mL; 3,33% (1 sample) was from 105 to 9,9x105 NMP/mL. The population of the total coliforms which was positive in 57,77% (26 samples) of the total analyzed samples were between 1 and 99 NMP/mL; 24,4% (11 samples) were between 102 and 9,9x102 NMP/mL; 2,22% (1 sample) were between 103 and 9,9x103 NMP/mL; 8,88% (4 samples) were between 104 and 9,9x104 NMP/mL; 4,44% (2 samples) between 105 and 9,9x105 NMP/mL and in 2,22% (1 sample) from 106 to 9,9x106 NMP/mL. The aerobic mesophiles microorganisms were presented in almost all the samples, being: 17,24% (10 samples) with a variation of 1 to 99 UFC/mL; 17,24% (10 samples) between 102 and 9,9x102 UFC/mL; 10,34% (6 samples) were between 103 and 9,9x103 UFC/mL; 25,86% (15 samples) between 104 and 9,9x104 UFC/mL; 17,24% (10 samples) between 105 and 9,9x105 UFC/mL; 10,34% (6 samples) between 106 and 9,9x106 UFC/mL and in 1,72% (1 sample) between 107 and 9,9x107 UFC/mL. However 3,33% (2 samples) showed to be negative. From the total analyzed samples, the SCP group presented in 78,57% (22 samples) with a variation between 1 and 99 UFC/mL; 3,57% (1 sample) between 102 and 9,9 x 102 UFC/mL; 10,71% (3 samples) between 103 e 9,9x103 UFC/mL and 7,14% (2 samples) were between 104 and 9,9x104 UFC/mL.

O objetivo deste trabalho foi avaliar o potencial antifúngico contra o fungo Aspergillus flavus, dos extratos de folhas de Eucalyptus staigeriana F. Muell., preparados a partir de folhas frescas, liofilizadas e secas ao ambiente, sob diferentes tempos de extração e por diferentes solventes extratores, tais como metanol, etanol e água a temperatura ambiente e água a 60ºC. Para mensurar o potencial antifúngico foi utilizada a técnica de poisoned food em meio BDA e o crescimento radial fúngico foi avaliado por seis dias. O percentual de inibição foi avaliado comparando-se as medidas do diâmetro radial de crescimento fúngico dos extratos com as placas controle contendo apenas os solventes. Como controle positivo foi utilizado o óleo essencial de E. staigeriana. Os extratos metanólicos apresentaram o melhor potencial antifúngico, seguido pelos extratos etanólicos e aquosos. A utilização das folhas frescas mostrou-se a melhor forma de preparação e não houve diferença significativa entre os tempos de extração 1h e 24h, indicando como processamento mais viável a extração em 1h. A Concentração Inibitória Mínima (MIC) foi mensurada para o extrato de melhor desempenho pela técnica de micropoços, aonde o crescimento fúngico foi monitorado por fluorescência derivada da reação da esterase fúngica com o diacetado de fluorescina. E o extrato que obteve o melhor resultado foi o extrato metanólico, com 1h de extração, a partir de folhas liofilizadas de E. staigeriana, e sua MIC foi de 26,75 L/mL, enquanto a do seu óleo essencial foi de 12,5 L/mL, demonstrando a eficiência relativa da extração com solventes extratores e sua praticidade e operacionalidade, quando se comparam com a extração de óleos essenciais. / This study aimed to evaluate the antifungal potential of Eucalyptus staigeriana F. Muell. leaf extracts against Aspergillus flavus. The extracts were prepared using fresh, lyophilized, and air-dried leaves, different extraction times, and different solvents, such as methanol, ethanol, water at room temperature, and water at 60ºC. To measure the antifungal potential, the poisoned food technique was used in PDA medium, and the radial growth of the fungus was evaluated for six days. The percentage of inhibition was assessed by comparing the measurements of the radial growth diameter of the fungus in the extracts with the control plates containing only the solvents. The essential oil of E. staigeriana was used as a positive control. The methanolic extracts presented the best antifungal potential, followed by the ethanolic and aqueous extracts. The use of fresh leaves was the best type of preparation and no statistically significant difference between 1-h and 24-h solvent extraction was found, indicating the 1-h extraction process as the most feasible. The extract presenting the best performance using the microwell technique had the minimum inhibitory concentration (MIC) measured, and the fungal growth was monitored by fluorescence derived from the fungal esterase reaction with fluorescein diacetate. The extract that achieved the best result the methanolic extract, with 1-h extraction from lyophilized leaves of E. staigeriana, and the MIC was 26.75 L/mL, while the essential oil was 12.5 L/mL, demonstrating the relative efficiency of the solvent extraction and its practicality and easy implementation when compared with the extraction of essential oils.

A produção industrial de carnes requer o conhecimento de seu comportamento durante o aquecimento. Visando o controle do processo, são necessários dados relativos às características microbiológicas da carne crua, a composição centesimal da carne cozida, o tratamento térmico aplicado e suas conseqüências na flora microbiana do produto. Avaliar a efetividade de diferentes tratamentos térmicos, os índices de qualidade e o rendimento dos cortes de carne são os objetivos deste trabalho. Foram utilizadas amostras de músculos Semitendinosus de carne bovina cozidas em dois meios de aquecimento, água e vapor, em duas temperaturas (70°C e 80°C). A efetividade do tratamento térmico aplicado às amostras foi avaliada através da elaboração da curva de penetração de calor em cada uma das amostras, calculando-se os valores P de pasteurização e as reduções decimais alcançada. Foram avaliadas as influências da temperatura e do tipo de aquecimento, isoladamente, na capacidade de retenção de água (CRA), assim como, a interação entre as variáveis. Os fatores i) perdas por cocção e ii) maciez objetiva foram analisados conjuntamente relacionando-as com as temperaturas e os tipos de aquecimento experimentados. Observou-se através de avaliação sensorial em que medida os fatores como a presença de tecido conjuntivo, suculência e sabor influenciaram a maciez do corte de Semitendinosus. Os resultados mostram que a temperatura de 70ºC não foi suficiente para a pasteurização neste experimento, tendo como microrganismo alvo o Clostridium botulinum tipo E. A maciez objetiva não foi influenciada por nenhum dos tratamentos. Na análise sensorial a variável maciez foi significativamente influenciada pela presença de colágeno de forma negativa e pela suculência de forma positiva. / The industrial manufacturing of meat requires the knowledge of its behavior in the course of the cooking process. To control the process it’s absolutely necessary to have data relative to the microbiological characteristics of the raw meat, the centesimal composition of the cooked meat, the thermal treatment applied and its consequences in the flora of the product. To evaluate the effectiveness of different thermal treatments, the levels of quality and the performance of meat cuts are the purposes of this work. Samples of Semitendinosus muscles of cooked bovine meat were submitted to two ways of heating, water and steam, under two temperatures (70ºC and 80ºC). The effectiveness of the applied thermal treatment to the samples was evaluated through the elaboration of the curve of penetration of heat in each one of the samples, calculating its P values of pasteurization and the decimal reductions reached. The influences of the temperature and the way of cooking have been evaluated, separately, in the water holding capacity (WHC), as well as the interaction between the variables. The factors i) cooking losses ii) objective tenderness were analyzed jointly relating them with the temperatures and the distinct ways of cooking. Sensorial evaluation was used to measure the influences of factors like conjunctive presence, juiciness and flavor over the tenderness of the cut of Semitendinosus. The experiment showed that the temperature of 70ºC was not enough to pasteurize the E type Clostridium botulinum microorganism. The objective tenderness was not influenced by any of the procedures. The sensorial analysis showed that tenderness was significantly influenced negatively by the presence of connective tissue and positively by the juiciness.

The increasing market demand for fresh produce promotes a keen interest in developing a rapid, sensitive and reliable method for monitoring plant health and determining the shelf-life of postharvest produce. The objective of this study is to explore the capability of Surface-enhanced Raman spectroscopy (SERS) in these applications. SERS integrates Raman spectroscopy which measures molecular vibrations and nanotechnology which enhances the weak Raman signals. Herein, we developed two SERS methods based on a surface detection approach using nanoparticles solution and a headspace detection approach using gold nanoparticles (AuNPs) fibers, to detect biochemical changes during postharvest storage of arugula leaves. Compared with surface detection, the headspace detection revealed significant spectral changes during the storage, particularly in the shifts around 500, 950 and 1030 cm-1. These changes analyzed using principal component analysis (PCA) to establish a prediction model for shelf-life determination. Through analyzing reference standard compounds, we identified the dimethyl disulfide (DMDS), 1-propanethiol and methanethiol (MT) were most likely to account for the signature spectra of headspace arugula at the late storage period due to the activities of spoilage bacteria. The headspace detection method was also applied to monitor the stress responses of living basil to abiotic stresses (pesticide/salinity). However, the volatile analysis of the basil plants response to abiotic stresses (pesticide/salinity) showed indistinctive results. In conclusion, the headspace detection based on SERS provides a new strategy for quality monitoring of fresh produce in the food industry.

Extra lean (3.3% fat) and lean (20.0% fat) hamburgers in three pH groups (≤ 6.0; 6.01-6.49; 6.50-6.92) were evaluated for cooking-temperature profile, total process lethality, and physical properties after cooking to 71°C by double-side frying on an electric grill. Neither cooking-temperature profile nor cooking time was affected by hamburger fat content or pH. Double-side frying to 71.1°C internal temperature was adequate for more than 6-log destruction of viable E. coli O157:H7 and Salmonella at the geometrical center of extra lean and lean hamburgers. The coldest spot was on the circumferential surface, as indicated by the presence of a red ring of undenatured myoglobin, and confirmed by the finite-element temperature distribution model. The effect of pH (5.80, 6.29, 6.73) on myoglobin denaturation in extra lean (3.3% fat) and lean (20.0% fat) hamburgers was studied. Compared to normal meat (pH= 5.8), raw extra lean ground beef of pH = 6.73 had significantly lower oxidation-reduction potential (ORP) value, lower concentration of metmyoglobin after 48 hr of refrigerated storage, and more distinct cherry-red color. Percent of myoglobin denaturation during cooking was affected mainly by pH and was not affected by total pigment or fat content of hamburgers. A pH ≥ 6.5 and ORP ≤ -200 mV were characteristic of dark-cutting beef In a third experiment, extra lean (3.5%) and lean (20.0%) beef patties were made from normal beef (pH= 5.70) and dark-cutting beef (pH = 6.60). Controls were made with no additives or with 1% salt and 10% added water. Various browning agents (1% glucose, 0.2% caramel colorant, 0.3% calcium peroxide, or 2.5% encapsulated lactic acid) were added with 10% water and 1% salt. Salt had a pronounced prooxidant effect on myoglobin. Distinctive absorption peaks at 541-548 nm and 577-582 nm indicated that the undenatured pigment in cooked patties was oxymyoglobin. Dark-cutting patties had more rubbery texture and slightly perceptible off-flavor. Patties with lactic acid were less juicy and had lower intensity of beef flavor than other patties, and moderate intensity of sour off-flavor. Addition of salt and encapsulated lactic acid to beef patty formulation could solve the problem of hard-to-cook patties.

The gut microbiota and its metabolites have vast impacts on the human digestive system, immune system, and health outcomes. Short chain volatile fatty acids (SCVFAs) present in feces can be representative of the interactions of the microbiota present in the gut. Low microbiota diversity in the human gut is highly associated with obesity and adverse health outcomes. Furthermore, the maternal microbiome has a direct impact on neonatal microbiota through various pathways such as environment, skin flora, breast milk composition, and vaginal secretions. This study is aimed to further understand the associations between various factors (maternal adiposity, gestational time, length of life, delivery mode, and race/ethnicity ) and neonatal microbiome and its metabolites, SCFA. Data (pre-pregnancy BMI, gestational time, length of life at time of sample collection, delivery mode, race/ethnicity, SCVFA profiles, fecal fermentation profiles, and 16s rRNA sequences, n=75) was obtained from 75 mother-infant dyads. Qiagen CLC Genomics Workbench was used to process 16s RNA data, generate quantitative and qualitative measures of alpha and beta diversity, and generate an analysis of the composition of microbiomes for differential abundances. Multiple metrics were analyzed for alpha and beta diversity and no significant differences were found for acetic acid (A), propionic acid (P), butyric acid (B), or APB combined. Shannon diversity index, a measure of Alpha diversity, showed no significant difference between groups in each subset. BMI differences were significant for no c-section vs. c-section and Black vs. White race/ethnicity. There were no significant differences found in PERMANOVA, a measure of beta diversity, or found in differential abundances among the groups.

A rising problem in agriculture is the increase of antibiotic-resistant Salmonella cases associated with chicken eggs, which transmit infection to humans. To counter this, new approaches to combat Salmonella in chickens and desiccated on eggshells are vital in the prevention of human foodborne illness. Disrupting signaling pathways with naturally occurring compounds provides a potential novel avenue for prevention of Salmonella infections, as this would disrupt sensing of these environments and inhibit subsequent optimal gene expression. Starting with signals identified in previous studies, salicylic acid was found to inhibit Salmonella desiccation survival on both eggshells and plastic. To expand upon this, a desiccation inhibition screen of 285 signals resulted in 9 additional potential desiccation inhibitors, including deoxyribose and guanine. By using natural signals to disrupt bacterial communication pathways, novel therapeutics that serve as viable antibacterial alternatives could be developed to prevent Salmonella contamination at a major source.

Growing consumer awareness of the health benefits associated with fruits and vegetables and demand for easy to prepare products has prompted the development of a wide variety of minimally processed fruits and vegetables. Minimally processed fruits and vegetables are often peeled, cut, or diced which compromise the produces’ natural protective barriers, exposing a nutrient rich medium and providing an ideal environment for the growth of microorganisms, including foodborne pathogens. The germination conditions of sprout vegetables consisting of relatively high temperatures and humidity, low light and abundance of nutrients are also conducive to the proliferation of foodborne pathogens. Recent outbreaks and recalls indicate additional measures are needed to improve food safety and maintain the integrity of the food industry. The objective of this research was to evaluate the efficacy of Lactic Acid Bacteria (LAB) against E. coli O157:H7, L. monocytogenes, and Salmonella spp. on apple slices and alfalfa sprouts and it’s influence on product quality. Apple slices inoculated with E. coli O157:H7, L. monocytogenes, and Salmonella spp. (each at 104 CFU/g) were treated with Lb. plantarum alone and in combination with Pediococcus acidophilus and P. pentosaceus (LPP) (107 CFU/g) while alfalfa seeds were inoculated with L. monocytogenes and Salmonella spp. (each at 101 CFU/g and 103 CFU/g) and treated with LPP (107 CFU/g). The growth of the microorganisms on the apple slices was assessed during five and seven days of storage at 4◦C and 20◦C, respectively. Growth on alfalfa seeds was reported during five days of sprouting at 20◦C. Populations of LAB were maintained between 7.0 log CFU/g and 8.0 log CFU/g throughout storage and sprouting on the sliced apples and alfalfa seeds, respectively. Although LAB had no significant effect on pathogen populations on apple slices during storage at 4°C (p > 0.05), populations were significantly different at 20°C (p < 0.05). Populations of L. monocytogenes in the presence of Lb. plantarum and LPP were 1.84 log CFU/g and 2.84 log CFU/g less than the controls after five days of storage at 20°C (p < 0.05). Populations of E. coli O157:H7 in the presence of Lb. plantarum and LPP were 1.83 log CFU/g and 1.86 log CFU/g less than the control after one and three days of storage, respectively. Finally, populations of Salmonella spp. were 0.86 log CFU/g less than populations in the absence of LPP after three days of storage. LPP had a significant effect on the growth of L. monocytogenes and Salmonella spp. on alfalfa seeds (p < 0.05). After five days of sprouting, populations of L. monocytogenes at an initial concentration of 101 CFU/g and 103 CFU/g on seeds treated with LPP were approximately 4.5 log CFU/g and 1.0 log CFU/g less than the untreated seeds, respectively. Populations of Salmonella spp. at an initial concentration of 101 CFU/g and 103 CFU/g were 1.0 log CFU/g less than the control. Overall, on apple slices the combination of Lb. plantarum with P. acidophilum and P. pentosaceus demonstrated greater efficacy than Lb. plantarum alone and reduction of L. monocytogenes by Lb. plantarum and LPP was greater than Salmonella spp. and E. coli O157:H7 on apple slices and alfalfa seeds, alike. LAB had a minimal effect on the quality of the apple slices and alfalfa seeds. LAB could be an effective strategy in reducing pathogen populations at abusive temperatures and germination conditions without influencing the quality of minimally processed fruit and vegetables.

The poultry industry is seeking an advanced chilling system that can improve chilling efficiency, microbial safety, and water consumption without compromising meat quality. The objective of this study was to evaluate the effects of sub-zero saline chilling methods on chilling efficiency, breast fillet tenderness and microbial reduction of broiler carcasses. Following evisceration and rinsing, broiler carcasses were randomly assigned to one of three chilling solutions: 1) 0% salt or ice water control (0% NaCl/0.5oC), 2) 3% salt (3% NaCl/-1.8oC), and 3) 4% salt (4% NaCl/-2.41oC) solutions. Broiler carcasses in sub-zero saline solutions reached the target internal temperature of < 4.4 oC in a faster rate than the 0% salt control, reducing the chilling time by 11% and 39 % for 3% NaCl/-1.8oC and 4% NaCl/-2.41oC solutions, respectively. There was no significant difference in breast fillet pH, regardless of chilling treatment (P < 0.05). However, the breast fillets from sub-zero saline solutions showed higher R-value and longer sarcomere length than those of control fillets (P < 0.05). Breast fillets excised from carcasses in 4% NaCl/2.41oC were significantly tenderized more than the control fillets, with an intermediate tenderness observed for the fillets from 3% NaCl/-1.8oC (P< 0.05). Before chilling, broiler carcasses contained mesophilic aerobic bacteria (MAB), Escherichia coli(E. coli), and total coliforms for 3.81, 0.78, and 1.86 log colony forming unit (CFU)/g, respectively. After chilling, the populations of E. coliand total coliforms were significantly reduced on the carcasses in 3% NaCl/-1.8oC and 4% NaCl/-2.41oCcompared to the control fillets (P< 0.05). There was no significant difference for MAB populations, regardless of treatment. Based on these results, chilling of broiler carcasses in 4% NaCl/-2.4 °C solution seems to be the best choice to improve chilling efficiency, meat tenderness, and microbial reduction compared to the control (0% NaCl/0.5ºC) and 3% NaCl/-1.8oCsolutions.

Listeria monocytogenes continues to challenge the dairy industry in causing post-process contamination of cheeses. To reduce risk of contamination, it is crucial to understand the growth and survival of pathogenic bacteria in cheese products and to develop post-process mitigation strategies. This study evaluated the fate of pathogens in reduced and regular sodium Mozzarella cheese, and the potential of Supercritical Fluid Extraction with CO2 (SFE) to reduce Listeria innocua on Mozzarella and Queso Fresco. The survival of L. monocytogenes, Salmonella, and E.coli O157:H7 (2-3 log CFU/g) in reduced sodium Mozzarella (1.62%), compared to regular sodium Mozzarella cheese (2.15%) at 4ºC and 12ºC for 90 and 30 days, respectively, was evaluated. Salmonella and E. coli O157:H7 populations decreased over incubation time at both temperatures and no difference (pListeria monocytogenes population also decreased during incubation time at 4°C regardless of the sodium concentration in Mozzarella cheese. However, there was a difference in the population of L. monocytogenes for regular and reduced sodium incubated 12°C, and its populations increased 1 log CFU/g in reduced sodium Mozzarella cheese. Additionally, this study determined the bactericidal effect of SFE on the population of L. innocua, a surrogate for L. monocytogenes, in Mozzarella and Queso Fresco cheese (6 log CFU/g) treated with SFE at two pressures and temperatures (120 bar at 40°C and 150 bar at 50°C) for 30 min. SFE treatment at 120 bar, 40°C for 30 min decreased L. innocua by approximately 3.0 and 3.5 log CFU/g in Mozzarella and Queso Fresco cheeses, respectively. SFE at 150 bar and 50°C reduced L. innocua by approximately 3.78 and 5.2 log CFU/g in Mozzarella and Queso Fresco cheeses, respectively. Since SFE had a minimal effect on the physico-chemical characteristics of the cheeses assayed, the results suggest SFE might be used to reduce L. monocytogenes in cheeses without negatively impacting product quality.