Essential oil of the leaves of Eugenia uniflora L.: Antioxidant and antimicrobial properties

AbstractEssential oil (EO) of the leaves of Eugenia uniflora L. (Brazilian cherry tree) was evaluated for its antioxidant, antibacterial and antifungal properties. The acute toxicity of the EO administered by oral route was also evaluated in mice. The EO exhibited antioxidant activity in the DPPH, ABTS and FRAP assays and reduced lipid peroxidation in the kidney of mice. The EO also showed antimicrobial activity against two important pathogenic bacteria, Staphylococcus aureus and Listeria monocytogenes, and against two fungi of the Candida species, C. lipolytica and C. guilliermondii. Acute administration of the EO by the oral route did not cause lethality or toxicological effects in mice. These findings suggest that the EO of the leaves of E. uniflora may have the potential for use in the pharmaceutical industry

Food Extract of Purple Yam (Dioscorea trifida L.f.) from Brazil: Optimization of Extraction Method, Characterization, In Vivo Toxicity, and Antimicrobial Activity

Purple yam (Dioscorea trifida) has high agricultural productivity in the Amazon region but has not been much investigated. Multivariate strategies were employed to optimize the method to obtain a food extract rich in functional compounds. The optimal conditions showed that the combination of 0.2 g of dried purple yam with 15 mL of citric acid (1%) under agitation in a water bath at 36 °C for 4 min yields an extract with a high content of peonidin-3-O-glucoside-5-O-glucoside, peonidin-3-O-feruloylglycosideum-5-O-glycosideum, peonidin-3-Op-coumaroylglycosideum-5-O-glycoside, quinic acid, apigenin 8-C-xyloside-6-C-glycoside (vicenin 3), quinic acid, apigenin 6-C-xyloside-8-C-glycoside (vicenin 1), and isorhamnetin-O-dihexoside. Our extract also presented 56.91 ± 0.76 mg 100 g−1 of total anthocyanins, 417.05 ± 11.37 mg 100 g−1 total carotenoids, and 493.09 ± 6.38 mg GAE 100 g−1 of total phenolic compounds. In a Galleria mellonella, in vivo model consumption safety was for up to 150 g by 70 kg of body weight. In addition, it inhibited the growth of Gram-negative bacteria (Salmonella typhimurium and Escherichia coli). The simple, fast, and ecofriendly extraction conditions, combined with the biological effects of our extract, gives us a great potential for its application in food or packaging technologies.This study was funded by the Coordination for the Improvement of Higher Education Personnel (Funding 001). The Foundation for Science and Technology (FCT, Portugal) provided financial support through national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LA/P/0007/2021). The FCT through the institutional scientific employment program contract provided contract for L. Barros. The BPI La Caixa Foundation, within project titled “AquaeVitae—Thermal Water as a Source of Life and Health” — “PROMOVE – The future of the Interior” call 2020, provided contract for T. Silveira.info:eu-repo/semantics/publishedVersio

QUALIDADE MICROBIOLÓGICA DE LINGÜIÇAS MISTAS DO TIPO FRESCAL PRODUZIDAS NA CIDADE DE PELOTAS (RS)

Foram avaliadas as condições higiênico-sanitárias de lingüiças mistas do tipo frescal, provenientes de 4 frigoríficos submetidos à inspeção sanitária estadual, e comercializadas em Pelotas (RS). Os resultados obtidos foram interpretados pela legislação vigente (RDC no 12/01) e pela anterior (Portaria 451), ambas do Ministério da Saúde (Brasil). Verificou-se que 17,86% das 32 amostras estavam contaminadas com Salmonella sp e 3,57% apresentaram Coliformes fecais acima dos parâmetros permitidos pela legislação em vigor. Com a alteração da legislação, a probabilidade de se encontrar amostras de lingüiça mista frescal contaminada por Coliformes fecais passou de 23,27% para 5,6%. MICROBIOLOGICAL QUALITY OF MIXING SAUSAGES OF THE FRESCAL TYPE PRODUCED IN PELOTAS - RS Abstract The hygienic-sanitary conditions of mixing sausages of the frescal type were evaluated, proceeding from 4 slaughterhouses with state sanitary inspection and commercialized in Pelotas (RS). The results were interpreted by the current legislation or the previous one, both of the Brazilian Health Ministry, in the interpretation of the results. It was verified that, 17,86% of the 32 samples were contaminated with Salmonella sp and 3.57% presented faecal coliforms above of the parameter allowed by the current legislation. With the change of the legislation, the probability to find samples of frescal mixing sausage with countings of faecal coliforms above of the maximum limits allowed by the legislation, passed of 23,27% to 5,6%

ESTAFILOCOCOS COAGULASE POSITIVA EM QUEIJOS MINAS FRESCAL E MINAS PADRÃO COMERCIALIZADOS EM PELOTAS, RIO GRANDE DO SUL

O objetivo deste estudo foi avaliar a presença de Estafilococos coagulase positiva (ECP) em amostras de queijos industrializados Minas Frescal e Minas Padrão, comercializados na cidade de Pelotas, Rio Grande do Sul. Foram avaliadas vinte e oito (28) amostras de queijo minas frescal e quarenta e quatro (44) de queijo minas padrão, coletadas no comércio local. Quatro amostras apresentaram contaminação acima do padrão estabelecido pela RDC 12, de 12 de janeiro de 2001 (ANVISA), sendo três de queijo minas frescal e uma de queijo minas padrão. A presença de ECP é preocupante uma vez que esses micro-organismos podem se multiplicar, produzir e secretar toxinas em níveis suficientes para causar intoxicação alimentar estafilocócica, enfermidade transmitida por alimentos de grande importância em saúde pública

PCR PARA DETECÇÃO DE STAPHYLOCOCCUS AUREUS ENTEROTOXIGÊNICOS EM QUEIJO MINAS FRESCAL

Staphylococcus aureus é um micro-organismo patogênico frequentemente encontrado em leite e derivados lácteos. Sua identificação e a determinação de sua enterotoxigenicidade indicam o potencial para produção de enterotoxinas (EE), as quais, após pré-formadas e ingeridas com o alimento, podem causar intoxicação alimentar. Entretanto, os métodos tradicionais de isolamento e identificação, além de demorados, apenas inferem sua toxigenicidade. O objetivo deste estudo foi padronizar PCR para amplificação de genes de dez EE utilizando DNA de S. aureus extraído diretamente de queijo Minas Frescal artificialmente contaminado. Reações específicas para os genes sea, seb, sec, sed, see, seg, sei, selj, selm e selo apresentaram sensibilidade ≥102 UFC de S. aureus por grama de queijo. Obteve-se amplifi cação com DNA extraído diretamente do queijo, sem necessidade de enriquecimento prévio da amostra, diminuindo o tempo total de análise. Com a PCR proposta neste estudo é possível detectar S. aureus enterotoxigênico em queijo Minas Frescal quando esse microrganismo encontrase em baixas concentrações celulares

Detection by multiplex PCR of Staphylococcus aureus , S. intermedius and S. hyicus in artificially contaminated milk

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