Physicochemical Characteristics, Microbiology, and Antioxidants of Goat Milk Kefir Supplemented with Clitoria ternatea L. Extract

Abstract

Introduction: Kefir is manufactured by inoculating milk with kefir grains, followed by a one-day fermentation phase at room temperature. The addition of extracts of Clitoria ternatea L. to kefir is used as a source of antioxidants which are beneficial for health. Objective: This study aimed to determine the effect of adding extracts of C. ternatea L. on physicochemical characteristics, pH, titratable acidity, total lactic acid bacteria, antioxidant activity, and total phenol of goat milk kefir. Methods: This study used fresh goat milk, kefir granules, and C. ternatea L. extract. The administration of C. ternatea L .extract on goat milk kefir was A (0%), B (1.5%), C (3.0%), D (4.5%), and E (6.0%). Physicochemical characteristics (water, protein, fat, pH, titratable acidity), total lactic acid bacteria, antioxidant activity, and total phenol were observed in this study. Results: The statistical analysis results showed that adding C. ternatea L. extract to goat milk kefir significantly (P˂0.05) decreased water content, pH, increased protein, total titrated acid, and antioxidant activity, total phenol and not significant (P˃0.05) to total lactic acid bacteria. In this study, the pH value was 3.65-4.10, the total titrated acid was 0.78-1.23%, and the total lactic acid bacteria was 7.42-7.87×10⁸CFU/ml. Conclusion: The results showed that adding C. ternatea L. extract could increase antioxidant activity and total phenol while also containing lactic acid bacteria, giving it the potential to be a nutrition probiotic food. Adding 1.5% C. ternatea L. extract to kefir produced the best results, with a pH of 3.88, titratable acidity of 0.88%, and total lactic acid bacteria of 7.87 108CFU/ml.