POTENTIAL SYMBIOTIC NON-DAIRY BEVERAGE FERMENTED BY LACTOBACILLI USING WATER-SOLUBLE EXTRACT FROM GERMINATED PURPLE CORN ADDED WITH XYLOOLIGOSACCHARIDES OBTAINED FROM CORNCOB

The intense demand for non-dairy functional foods and the use of agro-industrial co-products has driven research in developing new products. This work aimed the extraction and in vitro evaluation of xylooligosaccharides (XOS) obtained from corncob and their application in potential symbiotic beverages based on a water-soluble extract from the germinated corn. XOS was obtained by alkaline extraction of the xylans (NaOH 2M/60°C/3h) followed by hydrolysis with a xylanolytic cocktail produced by Fusarium sp. EA1.3.1 (388.18u.mL-1). XOS were subjected to fermentation by Lactobacillus rhamnosus and Lactobacillus plantarum. To produce the beverages, XOS was added to the water-soluble extract (1.5g.100mL-1), fractioned in two parts and fermented by Lactobacillus rhamnosus and Lactobacillus plantarum at 37°C (pH~3.8). The fermented samples were then stored at 4°C and subjected to pH, soluble solids (SS=°Brix), total solids (TS) and total lactic acids bacteria after 12h from the end of fermentation (T0) and every 7 days for 4 weeks (T28). In vitro evaluation has shown that there was an increase in optical density by 600mn (DO600nm) and reduced pH of both Lactobacillus rhamnosus (DO600nm 48h: 3.25±0.01; pH 48h: 6.12±0.07) as for Lactobacillus plantarum (DO600nm 48h: 3.04±0.04; pH 48h: 6.04±0.04), which indicates that these microorganisms partially ferment complex carbohydrates, due to the enzymes metabolism which can be used in association with XOS. The symbiotic drinks showed no difference in pH, SS and TS levels between T0 and T28 for both strains. The physicochemical results for Lactobacillus rhamnosus were: pHT0: 3.82±0.04; pHT28: 3.45±0.05; SST0: 9.33±0.08°Brix; SST28: 9.13±0.08°Brix; STT0: 11.05±0.03g.100g-1; STT28: 10.85±0.02g.100g-1. For Lactobacillus plantarum was observed: pHT0: 3.73±0.04; pHT28: 3.29±0.01; SST0:9.26±0.08°Brix; SST28: 8.96±0.06°Brix; STT0: 10.98±0.01g.100g-1; STT28: 10.59±0.02g.100g-1). It can be inferred that the product remained stable in both cases without post-fermentation action. Lactic acid bacteria remained above 108CFU.mL-1 for both samples until the end of the analyzed period.