MICROBIOLOGICAL AND PHYSICOCHEMICAL EVALUATION OF GRAPE KEFIR BEVERAGES

Water kefir (KA) is an essential source of probiotics, prebiotics, and antioxidants for vegans and dairy intolerants. Its probiotic effect is characterized by the association of different microorganisms in symbiosis in the gastrointestinal mucosa, which can promote anticarcinogenic, anti-inflammatory, antioxidant and gastroprotective actions. The present study aims to quantify microbiological and physicochemical requirements, according to IN 46/2007 (MAPA), of wine grape kefir beverages, produced in 24 hours of fermentation, using two types of water kefir grains (GC and GI) obtained by e-commerce. According to the instruction, lactic acid bacteria were counted using MRS agar; M17 agar medium for Lactobacillus and Lactococcus, respectively; aerobic mesophiles through the PCA agar medium; and yeasts through the medium Sabouraud agar; as well as the quantification of acidity content and ethanol concentration by HPLC-IR (liquid chromatography with refractive index detector). The microbiological count for KA with GC grains was: 8.24 ± 0.23 log₁₀ CFU/mL (PCA); 8.48 ± 0.02 (MRS), 8.58 ± 0.21 (M17); 8.85 ± 0.07 (Sabouraud). KA with GI grains presented: 8.77 ± 0.11 log₁₀ CFU/mL (PCA); 8.43 ± 0.06 (MRS); 8.50 ± 0.06 (M17); 8.82 ± 0.12 (Sabouraud). The microbiological parameters are in line with what is established in the regulations (minimum 10.7 for total lactic acid bacteria and minimum 10.4 for yeasts)