Effect of Germination and Probiotic Fermentation on pH, Titratable Acidity, Dietary Fibre, β-Glucan and Vitamin Content of Sorghum Based Food Mixtures

Abstract

Sorghum is an ancient, drought resistant cereal grain, often grows in semi-arid conditions where other cereal grains cannot. Lactic acid fermentation has been shown to improve the nutritional value of sorghum and the low pH generated during fermentation protects these foods against the growth of pathogenic bacteria. The present study has been planned to see the effect of germination and probiotic fermentation in enhancing the nutritional value of sorghum. Two types of food mixtures were developed using raw and germinated sorghum flour along with whey powder and tomato pulp in 2:1:1 proportion (w/w). The developed food mixtures were mixed with water, autoclaved, cooled and fermented at 37°C for 12 h with Lactobacillus acidophilus curd containing 106 cells/ml. These food mixtures were analysed for pH, titratable acidity, dietary fiber, β-glucan and vitamin content. Fermentation significantly reduced the pH and simultaneously increased the titratable acidity of germinated as well as non germinated food samples. Insoluble and total dietary fiber content increased significantly by fermentation (p<0.05), however, soluble fiber content decreased significantly. β-glucan content reduced significantly (p<0.05) in fermented sorghum based food mixture. The thiamine, riboflavin and niacin content increased significantly on fermentation (p<0.05) in both germinated and non germinated food mixture. This study has significance in terms of improving the nutritional quality of sorghum through probiotic fermentation.