Unveiling the Potential of Probiotic-Enriched Yogurt via Bacterial Fermentation

Yogurt has a jelly-like structure with consistent viscosity. It is made by using lactic
starter culture which lactic acid bacteria ferments lactose, or milk sugar, through its
enzymes. Common starter culture includes combination of Streptococcus thermophilus and
Lactobacillus bulgaricus. The pasteurized milk and yogurt starter culture was poured into
4 styrofoam cups. One of the four styrofoam cup was put used for pH and TSS monitoring.
The pH of yogurt changed from 6.5 down to 4.23 indicating yogurt has become acidic and
gave a sour acidic flavor with a light taste. The sugar content of the yogurt changed from
11 and went up to 12 upon adding the starter culture then went down to 8 after the
fermentation. The texture of the yogurt changed from watery to smooth, pudding-like.
Moreover, the appearance of the yogurt went from creamy to a thick, slightly firm with a
dripping consistency. While the color of the yogurt changed from naturally white to
yellowish white. In conclusion, a yogurt can be made from the live bacteria out of a
commercial regular yogurt. Therefore, it is possible that a homemade yogurt can be made locally and economically.