Functionality of Phytase of Saccharomyces cerevisiae MTCC 5421 to Lower Inherent Phytate in Selected Cereal Flours and Wheat/Pearl Millet-Based Fermented Foods with Selected Probiotic Attribute

Abstract

The partially purified extracellular phytase produced by Saccharomyces cerevisiae MTCC 5421 in formulated soy whey broth for yeast revealed an activity of 20.4 U/mL with specific activity of 12.0 U/mg and purification achieved was 5.6 fold. The partially purified phytase revealed a molecular mass of 94 kDa with pH and temperature optima of 5.0°C and 50°C, respectively. In a period of 2 h at 50°C, this phytase was able to lower inherent levels of phytic acid to 94% in pearl millet (Pennisetum typhoides) flour and 100% in refined wheat (Triticum aestivum) flour from an initial level of 0.19–0.34 g/100 g. During the preparation of wheat based (refined flour) fermented and baked product namely Naan, storage for 60 min of dough treated with partially purified phytase of S. cerevisiae revealed complete reduction of phytate. A similar action of phytase was also observed in the pearl millet based fermented product, Rabadi. Besides, the significant beneficial attribute achieved in Rabadi was the elaboration of short chain fatty acids such as acetic, butyric, and propionic acids in 12 h of fermentation with a probiotic culture of L. plantarum MTCC 5422 that had a viable population of 10.8 log₁₀ CFU/g.

Key words:

• Saccharomyces cerevisiae
• phytase
• pearl millet flour
• refined wheat flour
• fermented foods
• probiotic attribute

ACKNOWLEDGMENTS

The authors are thankful to the Director, CSIR-CFTRI, Mysore, for providing the facilities and interest in present work. The first author is grateful to the Council of Scientific and Industrial Research, New Delhi, for awarding a Research Fellowship.