Assessment of Physicochemical Composition and Enzymes Activity on the Effect of Fermentation Techniques During Production of Baobab Pulp Yoghurt

Abstract

The goal of the study was to evaluate the effect of fermentation time on some physicochemical properties and enzyme activity in yoghurt supplemented with baobab fruit pulp. Fresh baobab fruits were collected, processed, and then incorporated at 10% (w/v) into milk prior to fermentation. Fermentation of yoghurt samples was carried out for 0–15 hours. Changes in pH, TTA, sugar content (Brix), temperature, viscosity, and enzyme activities (amylase, protease, and lipase) were determined using the standard analytical method. The results indicated that the fermentation time significantly (p < 0.05) influenced TTA values that ranged from 0.12% to 0.89%, but the pH decreased from 4.67 to 3.83, within the acceptable range of yoghurt acidity. Sugar content increased slightly from 11.43% to 12.00%, and the apparent viscosity varied between 257.30 and 876.20 mPa.s at different fermentation times. Temperature slightly declined from 32.50 to 31.80°C. Enzyme activities were constant through the fermentation time of amylase (2.72 mg/mL), protease (31.65 mg/mL), and lipase (0.37 mg/mL) since no significant differences existed in the analyzed samples, which was obtained at p > 0.05. This means that supplementation of baobab pulp affects the physicochemical properties and did not affect changes in enzyme activities during fermentation. Baobab-enriched yoghurt is presented as a functional dairy product because enzyme activity did not change with increasing fermentation times.