Viability of native and commercial strain of lactobacillus rhamnosus in caprine milk drink with potentially probiotic grape juice

Abstract

The objective of this study was to develop a caprine fermented dairy beverage, using two strains of Lactobacillus rhamnosus, one commercial (Lr-32) and one native, isolated from artisanal cheeses and selected for probiotic and technological properties. The culture of Lb. rhamnosus EM1107 was prepared by culturing in MRS broth. For beverage production, the dairy base (milk, whey and sucrose) was heated to 37 ° C and added to the starter culture of Streptococcus thermophilus and commercial (Lr-32) or native culture Lb. rhamnosusEM1107. After fermentation, cooling and refrigerated rest, the fermented dairy base was added with grape juice. The viability of S. thermophilus and Lb. rhamnosus in beverages was monitored for 28 days of refrigerated storage, and the presence of coliforms at 45 ° C, E. coli, Staphylococcus DNAse positive, molds and yeasts, and Salmonella sp. The drinks were subjected to sensory acceptability testing, assessing the attributes appearance, taste, color, texture and overall acceptance. The populations of Lb. rhamnosus in beverages remained above 8 log CFU/mL during storage. The milk drink produced with Lb. rhamnosus EM1107 was highlighted by the highest concentration of the probiotic strain at the end of storage. Both beverages had good sensory acceptance, however, it was observed a tendency to obtain higher average scores for the added milk beverage of the autochthonous strain in all the sensorial attributes. The potentially probiotic strain of L. rhamnosus EM1107 showed promise for application in dairy drink fermented with grape juice.