The development of novel probiotic fermented plant milk alternative from flaxseed oil cake using Lactobacillus rhamnosus GG acting as a preservative agent against pathogenic bacteria during short-term refrigerated storage

Abstract

This study is aimed at investigating the suitability of flaxseed oil cake plant milk alternative (FOCM) to produce an innovative probiotic drink using Lactobacillus rhamnosus GG (LGG). Three variants of beverage were prepared: without supplementation, supplemented with 1% of glucose and supplemented with 1% of fructose. The viability of LGG, levels of polyphenolics, flavonoids and antioxidant activity were analysed. Moreover, color, viscosity and titratable acidity measurements were performed. Fermented beverages were artificially contaminated with pathogenic bacteria, and preservative effect of LGG was evaluated. The fermentation improved antioxidant activity, polyphenolics and flavonoids content, whereas viscosity of the samples decreased. During storage at 6°C for 48 hours the viability of LGG in all the samples was over the recommended probiotic minimum level (>106 CFU/mL). Supplementation with sugars significantly enhanced acidification of FOCM. Acidification was linked with preservative effect of LGG against pathogenic microflora. A significant reduction of Gram-negative pathogens was observed, whereas moderate activity was noted against Gram-positive bacteria. Due to the functional and biochemical characteristics conferred to the fermented beverages, the use of LGG showed adequate potential for industrial application. There is a potential for these products to be used where non-dairy alternatives for probiotic consumption are desired.