DEVELOPMENT OF A PROBIOTIC GRAPE BEVERAGE ENRICHED WITH RESIDUE FROM THE WINE INDUSTRY
In order to better explore the nutritional potential of grape and also contribute to the reduction of the pollution generated by the wine industry, the aim was to develop a fermented probiotic grape beverage with white wine residue. The behaviour of three Lactobacilli probiotic cultures was evaluated during fermentation and storage under different conditions of temperature and pH by cell counts and it was also accessed to determine beverage conditions (water concentration, fermentation time and storage viability). With an experimental design the pH, sucrose percentage and strains availability were evaluated. The beverage produced was tested with an intentional contamination with pathogenic and sanitary conditions indicators microorganisms to verify its behaviour monitoring cell growth and pH over 28 days. Antioxidant activity (TEAC), total polyphenol (Folin-Ciocalteu) and anthocyanin (Differential pH) content were also assessed with spectrophotometer. For statistics means, standard deviations, ANOVA, t test and Tuckey (p<0.05) were used. Lactobacillus casei subsp. rhamnosus ATCC 7469 showed cell counts above 108 CFU/ml for 70 days of cold storage. The presence of phenolic compounds in the grape skin has been shown to stimulate the growth of probiotic strains and its viability at the beverage was not affected by competition with Escherichia coli, Salmonella Enteritidis and Listeria monocytogenes contamination. Listeria and E. coli were inhibited by approximately 1 to 2 log over 28 days of storage at 4°C. The antioxidant activity, phenolic and anthocyanin contents increased 2.57, 1.28 and 1.76 times, respectively, during beverage storage. The prolonged contact between grape skins with the must seems to enhance extraction of compounds. The developed beverage allowed the growth and survival of L. rhamnosus at recommended rates for probiotioc foods, and compatible with the market needs. The introduction of a vegetable beverage naturally enriched with antioxidants, presence of fibers and sustainable aspect meets the global food market tendency.