Kinetic profile and anti-diabetic potential of fermented punica granatum juice using lactobacillus casei

Abstract

Lactobacillus casei NRRL-B-1922 was used to ferment whole fruit juice of Punica granatum. P. granatum which is also known as pomegranate could support the growth of L. casei even without nutrient supplementation. This can be seen from the maximum specific growth rate of the strain in shake flasks (0.08 h−1) and stirred tank bioreactor (0.11 h−1). Quercetin-3-glucoside was detected as the most abundant compound in the juice and its concentration increased up to 7.0 g/L at the maximum bacterial growth after 27-hs of fermentation in bioreactor. The results showed that the probioticated juice could have more than 80 % inhibition in dipeptidyl peptidase-4 (DPP4) assay. The glucose and fructose content were steadily reduced with the consumption rate of 0.51 g/L/h and 0.37 g/L/h, respectively in bioreactor. Therefore, the biotransformation of P. granatum juice by L. casei could increase the juice functionality by improving its inhibitory activity against DPP4.