RESUMO
Citrus by-products are inexpensive sources of polyphenols, important bioactive compounds with wide pharmaceutical and food applications. This study aimed to investigate the effect of enzymatic treatment of citrus by-products on the polyphenolic profile of extracts and assess the influence of extracts on the growth and adhesion of probiotics and foodborne pathogenic bacteria and on the inflammatory response of epithelial cells. Enzyme-assisted extraction altered the polyphenolic profile (as assessed by HPLC-DAD), increasing the content of aglycone flavanones (naringenin and hesperetin). Enzymatic extracts and aglycone flavanones exhibited higher antibacterial and prebiotic activities than non-enzymatic extracts and glycoside flavanones. However, a higher content of aglycones was not associated with higher anti-adhesion activity. Citrus extracts significantly (P ≤ 0.05) decreased the inflammatory response of Caco-2 cells to Salmonella Typhimurium adhesion. These results support the sustainable reuse of citrus agroindustrial wastes and indicate the potential of citrus extracts in preventing infection by foodborne pathogenic bacteria and inducing proliferation of probiotics in foods and the gut environment.
Assuntos
Aderência Bacteriana/efeitos dos fármacos , Citrus/química , Citocinas/imunologia , Extratos Vegetais/farmacologia , Antibacterianos/análise , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Células CACO-2 , Cromatografia Líquida de Alta Pressão , Flavanonas/análise , Flavanonas/isolamento & purificação , Flavanonas/farmacologia , Frutas/química , Humanos , Extratos Vegetais/análise , Extratos Vegetais/isolamento & purificação , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/crescimento & desenvolvimento , Salmonella typhimurium/fisiologia , Resíduos/análiseRESUMO
Enzymatic interesterification is used to manipulate oil and fat in order to obtain improved restructured lipids with desired technological properties. However, with raw materials containing significant amounts of bioactive compounds, the influence of this enzymatic process on the bioactivity of the final product is still not clear. Thus, the aim of this study is to evaluate the antioxidant potential and modulatory effects of two raw materials from the Amazonian area, buriti oil and murumuru fat, before and after lipase interesterification, on human hepatoma cells (HepG2). The results indicate that minor bioactive compounds naturally found in the raw materials and their antioxidant capacity are preserved after enzymatic interesterification, and that the restructured lipids modulate HepG2 endogenous antioxidant enzyme.
RESUMO
The quality of dairy products was investigated on 63 samples, being 24 nonindustrial-type ice creams, 19pasteurized milk creams and 20 of cheese pâtés. The samples were analyzed for searching thermo-tolerant coliforms, coagulase positive Staphylococcus, Salmonella spp., molds and yeasts, Bacillus cereus and Listeria monocytogenes. Additionally, characterization of the enterotoxigenic potential of B. cereus for the codified genes of enterotoxins NHE and HBL was also carried out by PCR technique; also the molecular subtyping of L. monocytogenes allelic polymorphism of virulence genes actA and hly was performed. Thirty-three percent (8/24) of ice cream samples and 15.8% (3/19) of milk cream samples did not comply with the microbiological standards established by RDC Nº12/2001 of ANVISA, because these products showed thermo-tolerant coliform counts above the established limits. L. monocytogenes was detected in one milk cream sample and those bacteria isolates were identified as belonging to the lineage I, which is potentially pathogenic to human. Potentially enterotoxigenic B. cereus was isolated from the three kinds of products analyzed in the present study. The degree of microbiological contamination found in this study reflects the inadequate hygienic-sanitary conditions in processing the dairy products, indicating the necessity of a best action, surveillance and control by sani
A qualidade de produtos derivados do leite foi verificada em 63 amostras, sendo 24 de sorvetes artesanais, 19 de cremes de leite pasteurizados e 20 de pâtés de queijo. As análises microbiológicas foram realizadas para averiguar a presença de coliformes termotolerantes, estafilococos coagulase positiva, Salmonella spp., bolores e leveduras, Bacillus cereus e Listeria monocytogenes. Além disso, foram realizados ensaios para efetuar a caracterização do potencial enterotoxigênico de B. cereus quanto aos genes codificadores das enterotoxinas NHE e HBL por meio de técnica PCR e a subtipagem molecular dos genes actA e hly deL. monocytogenes. As 33% (8/24) de amostras de sorvetes e 15,8% (3/19) de amostras de cremes de leite estavam em desacordo com os padrões microbiológicos estabelecidos para coliformes termotolerantes, de acordo com a RDC Nº12/2001 da ANVISA. A presença de L. monocytogenes foi observada em apenas uma amostra de creme de leite e os isolados da bactéria foram identificados como pertencentes à linhagem I, que é potencialmente patogênica ao homem. B. cereus com potencial enterotoxigênico foi isolado nos três grupos de alimentos estudados. O perfil de contaminação microbiológica observado nos produtos avaliados neste estudo serve de alerta para que os produtores melhorem as condições higiênico-sanitárias no processamento e da necessidade das autoridades sanitárias em est