Characterization of Caulerpa racemosa yogurt processed using Lactobacillus bulgaricus and Streptococcus thermophilus

Abstract

Lactic acid bacteria such as Lactobacillus bulgaricus and Streptococcus thermophilus in yogurt maintains the balance of the intestinal microflora by suppressing the growth of harmful bacteria. Dietary fibre and functional compounds in probiotic drinks also have a good effect on health. The modification of low-fat probiotic drinks is a value-added product and can be classified as a healthy drink. Caulerpa racemosa is a Chlorophyceae seaweed with high food fibre and functional compounds, including phenolic and chlorophyll as antioxidants. This study aimed to determine the effect of different lactic acid bacteria on the characteristics of the probiotic drink products by combining C. racemosa with low-fat cow’s milk. C. racemosa and low-fat cow’s milk with a ratio of 3:4 was fermented with Lactobacillus bulgaricus (A), Streptococcus thermophilus (B), and a combination of both (C). The products were analysed for protein and fat content, dietary fibre, total phenolic content, antioxidants activity, total lactic acid bacteria, total acid, pH, and with a sensory test for consumer preference. The addition of the different lactic acid bacteria had effects on the fat, antioxidants, dietary fibre, and total acid contents, while protein and total phenolic contents were not significantly different. The combination of L. bulgaricus and S. thermophilus produced a probiotic drink with the lowest amount of dietary fibre (1.27%) and total acid (0.64%), with antioxidant activity IC50 of 183.57 ppm and total phenolic content of 0.11 mg GAE/g. The preference test showed that the panellists preferred yogurt fermented with L. bulgaricus and S. thermophilus for its aroma, texture, and colour.