Effect of Synbiotic Interaction of Fructooligosaccharide and Probiotics on the Acidification Profile, Textural and Rheological Characteristics of Fermented Soy Milk

Preparation of yoghurt-like product from non-dairy raw material, such as soy with probiotic and prebiotic is a novel development in the field of fermented functional foods. This research work aimed at finding the new combinations of probiotics Lactobacillus acidophilus, Lactobacillus plantarum and Lactobacillus rhamnosus, which can give good product characteristics to fermented soy milk. Fructooligosaccharide was added in an attempt to reduce the after-taste of soymilk, improve acidification rates and growth of probiotics. Acidification rate was enhanced with L. acidophilus–L. plantarum and L. acidophilus–L. plantarum–L. rhamnosus, resulting in a shorter time to reach pH 4.5. Hardness was significantly (P?G′ (1,279.70–1405 Pa) and lower tan δ (0.273–0.346) values which signifies firmer and solid-like character of the gel formed by probiotic bacteria. Soy yoghurt made with L. acidophilus–L. plantarum resulted in improved product characteristics with shorter t _pH 4.5 (4.28 h). Soy yoghurt fermented with L. acidophilus–L. plantarum showed more than 9 log cfu/ml count which is required for probiotic functional food.