Resumo O processamento mínimo do pinhão ocasiona aumento na perda de massa, deterioração fisiológica e crescimento de microrganismos. Assim, objetivou-se com este estudo avaliar a conservação de pinhão minimamente processado usando revestimentos de quitosana e gelatina. Os pinhões foram minimamente processados e revestidos com quitosana, gelatina e quitosana/gelatina, pela técnica camada sobre camada. Em seguida, foram secos sob ventilação forçada, acondicionados em embalagem de polietileno tereftalato e estocados a 4 °C por 10 dias. Foram realizadas análises de perda de massa, pH, açúcares redutores, vitamina C e cor, além de análises microbiológicas e análise sensorial. Benefícios foram observados com o uso dos revestimentos de quitosana e gelatina, especialmente quando aplicados pela técnica camada sobre camada. A melhor combinação de resultados foi obtida com a aplicação do revestimento quitosana/gelatina, que possibilitou a redução da perda de massa e do crescimento de fungos e bactérias psicrotróficas aeróbias. O revestimento não retardou o processo de maturação e, consequentemente, maiores teores de vitamina C foram obtidos. Os revestimentos não influenciaram o sabor e o aroma dos pinhões minimamente processados. O processamento mínimo pode incentivar o consumo da semente e, além disso, a conservação, utilizando revestimento comestível à base de quitosana/gelatina pela técnica layer-by-layer, associado à refrigeração, ampliou a vida útil das sementes.

Abstract The minimal processing of pinhão causes an increase in mass loss, physiological deterioration and the growth of microorganisms. Thus, this study aimed to evaluate the conservation of minimally processed pinhão using edible chitosan and gelatin coatings. The pinhões were minimally processed and coated with chitosan, gelatin and chitosan/gelatin using the Layer-by-Layer (LbL) technique. They were then dried under forced ventilation, packaged in a polyethylene terephthalate package and stored at 4 °C for 10 days. The analyses performed were weight loss, pH, reducing sugars, vitamin C, color, microbiological analysis and sensory analysis. Benefits were observed with the use of chitosan and gelatin coatings, especially when applied using the LbL technique. The best combination of results was obtained with the application of the chitosan/gelatin coating, mainly reduction of weight loss and inhibition of growth of fungi and aerobic psychrotrophic bacteria. The coating did not retard the maturation process, thus, higher vitamin C contents were obtained. The coatings did not influence the taste and aroma of minimally processed pinhão. Minimal processing can encourage the consumption of seeds, besides this, the conservation using edible coating based on chitosan/gelatin, applied with the LbL technique associated with refrigeration, extended their shelf life.

ABSTRACT Synthetic preservatives are widely present in processed foods, but most of them have carcinogenic potential, requiring the development of new natural alternatives such as fruit extracts, for microbial control. The objective of the study was to evaluate the chemical characterization, antioxidant, and antimicrobial activity of the sugar apple pulp (Annona squamosa L.). Physicochemical characteristics were evaluated, an extract was prepared, and its antioxidant activity by DPPH method and antimicrobial by disk diffusion. Minimal inhibitory concentration and minimum bactericidal concentration against strains of Salmonella typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus were evaluated. The physicochemical analysis revealed that sugar apple pulp had 75.0% moisture, 3.0% ash, 4.0% protein, 0.2% lipids, 3.3% fibers, and 14.5% carbohydrates. The antioxidant activity of the extract by the DPPH method was 20.6%. The pulp extract from the sugar apple had inhibition zone for Staphylococcus aureus, satisfactory inhibitory effect against Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, and Salmonella Typhimurium, but did not present a bactericidal effect. Sugar apple pulp presents adequate levels of nutrients and potential for food application due to its microbiological activity and antioxidant properties.

RESUMEN Los conservantes sintéticos están ampliamente presentes en los alimentos procesados, pero la mayoría tienen potencial carcinogénico, lo que requiere el desarrollo de nuevas alternativas naturales para el control microbiano, como los extractos de frutas. El objetivo del estudio fue evaluar la caracterización química, la actividad antioxidante y antimicrobiana de la pulpa de manzana de azúcar (Annona squamosa L.). Se evaluaron las características fisicoquímicas, y se evaluó su actividad antioxidante mediante el método DPPH y antimicrobiano por difusión en disco, concentración inhibitoria mínima y concentración bactericida mínima contra cepas de Salmonella Typhimurium, Escherichia coli, Listeria monocytogenes y Staphylococcus aureus. El análisis fisicoquímico reveló que la pulpa de manzana de azúcar tiene 75.0% de humedad, 3.0% de cenizas, 4.0% de proteínas, 0.2% de lípidos, 3.3% de fibras y 14.5% de carbohidratos. La actividad antioxidante del extracto por el método DPPH fue del 20.6%. El extracto de pulpa de la manzana de azúcar tenía zona de inhibición para Staphylococcus aureus, efecto inhibidor satisfactorio contra Staphylococcus aureus, Escherichia coli, Listeria monocytogenes y Salmonella Typhimurium, pero no presenta efecto bactericida. La pulpa de manzana de azúcar presenta niveles adecuados de nutrientes y potencial para la aplicación de alimentos debido a su actividad microbiológica y propiedades antioxidantes.

Resumo O presente estudo avaliou a presença de Salmonella spp. em 89 amostras de produtos cárneos comercializados na região sul do Rio Grande do Sul e, a partir dos isolados obtidos, foi verificada a capacidade de resistência a agentes antimicrobianos e de formação de biofilme em superfícies de poliestireno. Foi constatada a presença de Salmonella spp. em 19,1% das amostras avaliadas e, dos isolados obtidos, 40% mostraram resistência a pelo menos um dos agentes antimicrobianos testados e 33,3% manifestaram-se multirresistentes. Apenas o antimicrobiano amicacina (30 µg) foi eficaz na inibição de todos os isolados testados. Nenhum isolado mostrou-se capaz de formar biofilmes em superfícies de poliestireno.

Abstract The objective of the study was to evaluate the presence of Salmonella spp. in 89 samples of meat products marketed in southern Rio Grande do Sul and from isolates obtained was verified the ability of resistance to antimicrobials and biofilm formation on polystyrene surfaces. The presence of Salmonella spp. was found in 19.1% of the samples. Of the isolates obtained, 40% showed resistance to at least one of the tested antimicrobials and 33.3% expressed multiresistant. Only the antimicrobial amikacin (30 µg) was effective in inhibiting all isolates tested. No isolate was able to form biofilms on polystyrene surfaces.

Abstract This study aimed to evaluate the application of good practices in hotel restaurants in Southern Brazil, relate these practices to the microbiological quality of the food offered, in addition to identifying contamination sources. The food and beverage sector of four hotels was evaluated by means of a checklist based on the Resolution 216/2014 of Agência Nacional de Vigilância Sanitária and microbiological analyzes. Surface, utensil, equipment and handlers’ hand samples were collected for coagulase positive Staphylococcus and thermotolerant coliform count. Isolates obtained from these culture counts were compared by band profiles obtained by rep-PCR. According to non-conformities observed, only one hotel was rated as excellent in good practices avaliation. Some microbiological analysis exceeded the allowed limit for the analyzed microorganism count, revealing failure in the hygiene-sanitary process. Genetic similarities between some food samples and handlers’ hands and utensils were identified. These results showed inadequacies in the process of food care and handling which may compromise the quality of food offered to custumers.

RESUMO: Esta pesquisa teve como objetivo detectar diretamente em amostras de leite contaminado artificialmente Staphylococcus coagulase positiva (ECP) por multiplex PCR (mPCR). Cepas padrão e isolados de S. aureus, S. epidermidis, S. hyicus, S. intermedius, Listeria monocytogenes e Escherichia coli foram utilizados no estudo. Foram utilizados primers específicos para o gene nuc (NUC1-NUC2 para o S. aureus, NUC3-NUC4 para o S. hyicus e NUC5-NUC6 para o S. intermedius ). Foi possível detectar as três espécies-alvo por mPCR, formar diretamente nas amostras de leite integral bovino, com especificidade adequada e limite de detecção aceitável para identificação de espécies de Staphylococcus coagulase positiva (ECP) em alimentos. A especificidade foi determinada por meio da amplificação de fragmentos específicos das espécies e o limite de detecção foi avaliado pelos limiares de detecção obtidos para as três espécies (103 UFC mL-1 para as espécies presentes nas amostras de leite contaminadas artificialmente).

ABSTRACT: This research aimed to detect coagulase-positive Staphylococcus (CPS) directly in samples of artificially contaminated milk, using multiplex PCR (mPCR). Standard and isolated bacterial strains of S. aureus, S. epidermidis, S. hyicus, S. intermedius, Listeria monocytogenes and Escherichia coli species were used, evaluating the specificity and detection limit of mPCR, for artificially contaminated UHT milk. Primers specific for the nuc gene (NUC1-NUC2 were used for S. aureus, NUC3-NUC4 for S. hyicus and NUC5-NUC6 for S. intermedius). It was possible to detect the three target species by mPCR, directly from bovine whole milk, with adequate specificity and acceptable detention limit for identification of coagulase-positive Staphylococcus (CPS) in foods. The specificity was determined by the amplification of species-specific fragments, and the detection limit was assessed by the detection thresholds obtained for the three species (103 CFU mL-1). From these results, the mPCR described, with the proposed set of primers, has the potential for use in precise identification and differentiation between CPSs in milk samples.

As espécies enterotoxigenicas Staphylococcus aureus, S. hyicus e S. intermedius apresentam características muito similares, tornando difícil a sua identificação através dos métodos microbiológicos convencionais. Este trabalho visou o desenvolvimento de um PCR multiplex (mPCR) para a identificação S. aureus, S. intermedius and S. hyicus, utilizando, para isso, sequencias do gene nuc. Os resultados obtidos sugerem que os primers utilizados foram específicos para as três espécies de Staphylococcus avaliadas, com um limite de detecção de10² UFC.mL-1.

The enterotoxigenic species Staphylococcus aureus, S. hyicus and S. intermedius show very similar characteristics, making their identification through conventional microbiological methods difficult. This study aimed at the development of a Multiplex PCR (mPCR) for the identification of S. aureus, S. intermedius and S. hyicus using the nuc gene as the target sequence. The results obtained suggest that the set of primers used was specific for the three species of Staphylococcus evaluate with a detection limit of 10² CFU.mL-1.

Sessenta e cinco cepas de estafilococos coagulase positiva foram identificadas em nível de espécie, através da amplificação, por PCR, de seqüências do gene coa, específicas para S. aureus, e do gene nuc, específicas para S. intermedius e para S. hyicus.

Sixty-five strains of coagulase positive staphylococci (Staphylococcus aureus, S. intermedius and S. hyicus) were identified at species level by PCR amplification of the coa gene, specific for S. aureus, and of the nuc gene, specific for S. intermedius and for S. hyicus.