Effect of Nutritional Factors on Growth Behaviour, Proteolytic, β-Glucosidase and β-Galactosidase Activities of Lactobacillus Cultures during Soy-Drink Fermentation

Sujit Das,Subrota Hati,Birendra Kumar Mishra

doi:10.12944/crnfsj.8.3.18

Abstract

In this study, inulin, whey protein concentrate (WPC 70) and skimmed milk powder (SMP) were used as nutritional factors to improve the quality of soy-drink fermented with indigenous Lactobacillus cultures. The growth behaviour (pH, titratable acidity, viable cell count), β-glucosidase, β-galactosidase, and proteolytic activity of indigenous Lactobacillus cultures were studied with various nutritional supplements in soy-drink. Two-way analysis of variance (ANOVA) was applied and the post-hoc comparison was acquired by Tukey’s HSD test for all the data presented in the study. Due to the supplementation of nutritional factors, the pH dropped as a bit of lactic acid production was also observed due to a lack of lactose. The supplements also provided extra nutrition during their growth in different incubation hours. At 2% rate of WPC 70 supplementation, maximum proteolysis (1.17 O.D.) was found by L. fermentum K7. L. fermentum K16 showed the highest β-glucosidase enzyme activity (0.154µM/mL/min) and maximum β-galactosidase activity (0.339 µM/mL/min) was observed for L. acidipiscis K27 at 2% rate of inulin supplementation to soy-drink. In the preparation of novel fermented foods and beverages, the conjunction of nutritional supplements with indigenous Lactobacillus cultures can potentially be used.

Highlights

Soy-drink attracts consumers as a substitute for dairy-based food products because of its protein content and lack of cholesterol and lactose
Β-Glucosidase Activity of Lactobacillus Cultures In Soy Drink Supplemented with Nutritional Factors The β-glucosidase activity of the Lactobacillus cultures incorporated in soy-drink supplemented with inulin, skimmed milk powder (SMP) and WPC 70 at 2% level were interpreted by analyzing the hydrolysis rate of p-nitrophenol β-D-glucopyranoside (HiMedia, India)
This will be accomplished by fermentation with additional nutritional supplements thereby improving the overall digestion. pH, titratable acidity and viable lactic bacteria counts were determined after various time periods viz.[0, 3, 6, 9, 12] and 24 h of soy-drink fermentation at 37°C supplemented with inulin (Table 1), WPC 70 (Table 2) and SMP (Table 3), at the rate of 2%

Summary

Introduction

Soy-drink attracts consumers as a substitute for dairy-based food products because of its protein content and lack of cholesterol and lactose. It is an excellent source of high protein, vitamin B2, vitamin B12, potassium, and isoflavones. Inulin, when incorporated into yogurt, shows its efficacy as a bulking agent, the substitution of fats, lower-calorie sweeteners, and modification of textures, thereby predominantly changing the organoleptic perception fermented food products.[3] It is believed that soy drink supplementation with skimmed milk powder (SMP) promotes nutritional parameters and associated health applications, including the development of active soy aglycones from glucosidic conjugates. WPCs are capable of induction of textural features of dairy foods, and they possess sufficient concentrations of lactose that serve as a matrix where biosynthesis of fermentable sugars occurs by the action of lactic acid bacteria.[5]

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Results

Conclusion