Reduction of Phytic Acid in Food Using Specific Starter Cultures

Abstract

In the present study, twenty six strains of previously isolated Lactic acid bacteria (LAB) were examined for phytate degradation. A strain of Lactococcus lactis subsp. lactis, showed highest phytate reduction in de Man Rogosa Sharpe (MRS) media and was examined further. Incubation with optimized parameters such as temperature of 37˚C, inoculum size,(5%) sucrose, di hydrogen phosphate as nitrogen source and casein as protein source, agitation, pH of 5 resulted in an overall reduction of 40% phytate. Phytate reduction was mediated primarily by intracellular phytase. When composite dough (wheat flour +Vigna mungo flour) was fermented with Lactococcus lactis, same reduction of phytic acid was achieved at 37˚C and pH 5.0, no reduction of phytate could be observed in uninoculated composite sourdough. Phytate reduction remained unaltered in the composite sourdough matrix, indicating that phytase activity was unaffected by food matrix conditions. Phytate did not hamper biofilm producing capabilities of Lactococcus lactis and the reduction achieved was higher (50.26%) than that observed for plank tonic cells (40%). Thus the results suggest Lactococcus lactis as a potential phytate reducing strain