Aguamiel Enhance Proteolytic Activity and Survival of Lactiplantibacillus pentosus ABHEAU-05 during Refrigerated Storage of a Fermented Milk

Abstract

Different carbon sources, such as prebiotics, have promoted probiotics’ survival during refrigerated fermented milk storage. These compounds stimulate both the metabolic response and the resistance of probiotics to adverse conditions, such as low temperatures. That is why the objective of this study was to evaluate the kinetic parameters of growth, the proteolytic profile, and the survival of Lactiplantibacillus pentosus ABHEAU-05 in fermented milk added with aguamiel as a prebiotic source during refrigerated storage. Inulin was used for control experiments. A 12% w/v powdered skimmed milk solution was inoculated with L. pentosus ABHEAU-05 (106 CFU/mL). It was fermented at 37 °C until a pH of 4.5, and the kinetic parameters were calculated. Analysis of survival and proteolytic profile during refrigeration storage (4 °C for 21 days) was carried out. The survival of the microorganism was determined by viable count on MRS agar, the production of free amino groups by the TNBS method, and the accumulation of low molecular weight peptides by polyacrylamide gel electrophoresis (SDS-PAGE). The pH of 4.5 was reached 26 h before the control. The maximum concentration of viable cells was 108 CFU/mL at the fermentation’s end and maintained throughout the refrigerated storage. With the analysis of the proteolytic profile, high metabolic activity was demonstrated during fermentation and refrigerated storage in milk with aguamiel. The accumulation of low molecular weight peptides and the generation of free amino groups were higher than the control results. It was verified that aguamiel is a carbon source with the potential for developing and maintaining the probiotic L. pentosus ABHEAU-05 in fermented milk.