Impact of banana puree on viability of probiotic soy yoghurt during storage

Abstract

The present investigation was made with an attempt to manufacture banana based probiotic soy yoghurt with addition of probiotic culture and banana puree, were examined. Probiotic soy yoghurt samples were produced from soy milk fermented with yoghurt and probiotic culture i.e. Streptococcus thermophilus NCDC-074, Lactobacillus delbrueckii ssp. bulgaricus NCDC-009, Lactobacillus acidophilus NCDC-15 and Bifidobacterium bifidum NCDC-235. The viability (SPC) of these four strains were analyzed during storage at refrigerated temperature with the selective media of MRS, ST, MRS-sorbitol and MRS-maltose agar. These counts generally decreased during the storage period. Supplementation of banana fortified soy yoghurts with 5, 10 and 15% of banana puree, improved the viability of probiotic bacteria during storage period. However, the yoghurt supplemented with banana puree, at 15% level, showed highest viability (10 6 cfu/g) among all treatment combinations up to four weeks of refrigerated storage.