The effect of microbial transglutaminase on probiotic fermented milk produced using a mixture of bovine milk and soy drink

Abstract

In this study, the effects of microbial transglutaminase (m-TGs) enzymes on the physicochemical, microbial and sensorial properties of probiotic fermented milk produced using a mixture of bovine milk and soy drink were investigated. Probiotic fermented milk samples were prepared by 3:1 v/v bovine milk, 0.002 w/v soy drink and 0, 0.5, 1, 1.5 U m-TGs per gram of milk protein. The starter culture used was ABT-2 1000 I (a mixture of Lactobacillus acidophilus LA-5, Bifidobacterium animalis subsp. lactis BB-12 and Streptococcus thermophilus). Viscosity and hardness values increased with increased transglutaminase ratio, whereas syneresis values decreased. All samples had an apparently acceptable number of probiotic bacteria over the storage period. While the minimum and maximum percentage ratios of alcohol components and carbonyl components in total volatile aromatic components of fermented milk samples are 24.75-30.70% (v/v) and 65.66-71.96% (v/v) during storage time, the minimum and maximum percentage ratios of organic acids and esters are 0.56-2.54% (v/v) and 0.73-1.57% (v/v).