Effect of Lactic Acid Bacteria on the Physicochemical, Anti-Inflammatory Antioxidant and Microbiological Properties of Kombucha

Yew, Kai Ying (2024) Effect of Lactic Acid Bacteria on the Physicochemical, Anti-Inflammatory Antioxidant and Microbiological Properties of Kombucha. Final Year Project (Bachelor), Tunku Abdul Rahman University of Management and Technology.

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Abstract

Kombucha is a fermented beverage resulting from the fermentation of sweetened tea by adding the symbiotic culture of bacteria and yeasts (SCOBY). It is considered as a healthy and functional beverage because it promises several health benefits. Probiotics are defined as live microorganisms that are beneficial to health when consumed in adequate amounts. In this study, about 1 g/L of Lactobacillus plantarum was added into the kombucha black tea at the beginning of fermentation. Then, the effects on its physicochemical, antioxidant, anti-inflammatory and microbiological properties in kombucha were investigated while comparing the changes throughout the 14 days fermentation period. Physicochemical analysis demonstrated that the kombucha added with LAB has a lower pH of 2.94 ± 0.02, as well as a Brix value of 7.1 ± 0.00 with the total titratable acidity of 1.10 ± 0.00%. The color of kombucha added with LAB showed the lightest color compared to the normal kombucha which has a darker color. Moreover, the total phenolic content in kombucha added with LAB increases to 689.3 ± 4.50 mg GAE/100 mL after 14 days, which the normal kombucha only contained 583.9 ± 3.43 mg GAE/100 mL. There is a significant increase (p < 0.05) in antioxidant properties after fermentation, with the kombucha containing LAB showing the highest antioxidant after 14 days fermentation. Next, the anti-inflammatory activity of kombucha added with LAB showed the higher value (14.10± 0.66%) compared to normal control (9.33 ± 0.31%). Lastly, the kombucha added with LAB managed to have a higher lactic acid bacteria count (7.15 ± 0.04 log10 CFU/mL), yeast count (5.28 ± 0.03 log10 CFU/mL) and total plate count (6.65 ± 0.06 log10 CFU/mL) compared to normal kombucha. Overall, kombucha prepared with additional LAB served to provide higher antioxidant and anti-inflammatory activity for 14 days fermentation