Survival and metabolic activity of probiotic bacteria in green tea

•Three probiotics survive in tea extracts better than in saline solution.•One selected probiotic incubated in tea did not enhance its biological activity.•The probiotic incubated in ECGC or rutin solutions increases its bioactivity.

The aim of this study was to determine the enzymatic activity and survival of three probiotic strains (Lactobacillus paracasei LAFTI-L26, Lactobacillus acidophilus LAFTI-L10 and Bifidobacterium animalis ssp. lactis LAFTI-B94) during incubation in six different varieties of green tea extracts. The polyphenol content, antioxidant, antimicrobial and antihypertensive properties in green tea (variety Wu Lu Mountain) and in two standards (epigallocatechin-3-gallate and rutin) were also investigated before and after incubation with B. animalis B94. The green tea extracts permitted the survival of the selected probiotic strains better than the saline solution, with B. animalis B94 maintaining the highest levels of viable cells. These selected probiotic bacteria exhibited β-glucosidase, β-galactosidase and α-rhamnosidase activity. The antioxidant and antihypertensive properties of standard solutions of epigallocatechin-3-gallate and rutin increased after incubation with B. animalis B94, caused by polyphenol content reduction and the formation of other more highly biologically active metabolites. However, during the incubation of green tea with B. animalis B94, changes in the concentration of the most abundant green tea polyphenols did not enhance the biological activity.