| Congresso Brasileiro de Microbiologia 2023 | Resumo: 965-1 | ||||
Resumo:Porungo cheese is a traditional artisanal cheese made from raw milk by small producers in the southwest region of the São Paulo state. Due to traditional production methods, this cheese harbors a diverse yet unknown microbiota. Lactic acid bacteria (LAB) are dominant in these cheeses and play a crucial role in fermentation, acidification, and coagulation, contributing to their sensory, nutritional, and aromatic characteristics. In addition to acid production, LAB may exhibit proteolytic and lipolytic activities and synthesize antimicrobial compounds such as bacteriocins, which act as natural preservatives in food. This study aimed to assess the biotechnological potential of eight isolates of lactic acid bacteria obtained from fermented-whey of Porungo cheese in the elaboration of a fermented dairy beverage. The bacteria, identified as belonging to the genera Streptococcus and Lactococcus, were cultured in reconstituted skim milk at 12% and then inoculated into 100 ml of commercially sterilized whole milk. The milk samples were kept at 40 °C for 10 hours and then refrigerated at 4 °C for 30 days. At 0 hours, 6 hours, 10 hours, 24 hours, 15 days, and 30 days, samples were collected and analyzed for microbial population on MRS agar, pH, and titratable acidity. Proteolytic and lipolytic activities were assessed in the product after 30 days of storage by determining the non-protein nitrogen content and free fatty acids content, respectively. The isolate that showed the best growth (7.4 log CFU/ml) and the highest acidification capacity was QP40 (Lactococcus sp.) at 15 days. This isolate reduced the pH to 4.6 within 10 hours of fermentation. Concerning proteolytic activity, four isolates (QP32, QP40, QP79, QP83) exhibited significantly higher non-protein nitrogen content (p<0.05) compared to the control (0-hour time point). Six out of eight isolates showed lipolytic activity, evidenced by a significant increase (p<0.05) in free fatty acids content compared to the control (0-hour time point). These results indicate the potential use of the isolates obtained from the fermented-whey of Porungo cheese as starter or adjunct cultures in food fermentation processes, aiming to obtain products with improved digestibility and reduced irritability in individuals with intolerances and allergies. Palavras-chave: Bioprospecting, Food microbiology, Traditional raw milk cheese Agência de fomento:CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) | |||||