Microbiological Characteristic and Nutrition Quality of Goat Milk Kefir Based on Vitamin D3 Fortification Time

Goat milk kefir fortified with vitamin D-3 is expected to benefit individual with insulin resistance. Different vitamin D-3 fortification time allegedly effect microbiological characteristic and nutrition quality of goat milk kefir due to its microbial growth curve, thus this study aimed to analyze those parameters. This study was an experimental research. This study contains five treatments (vitamin D-3 fortification at 0, 6, 12, 18, or 24 hours of fermentation) and a group of control. Total lactic acid bacteria, vitamin D-3, protein level, fat contain, crude fiber, viscosity, and pH was analyzed by Total Plate Count, spectrophotometry, Bradford method, Babcock method, gravimetric analysis, Ostwald method, and pH meter respectively. Time of vitamin D-3 fortification significantly effect vitamin D-3 content (p=0,021), fat content (p=0,001), crude fiber (p=0,0001), viscosity (p=0,010), and total lactic acid bacteria (p=0,048). The highest vitamin D3content was found on the group fortified at 6 hours of fermentation. All treatment groups has lower fat content and crude fiber content than control group. Total LAB in all group meet the Codex standard (>10(7) CFU/ml). Control group and fortification group at 24 hours of fermentation have higher viscosity than other groups. There was no significant difference found in goat milk kefir protein level (p=0,262) and pH (p=0,056) despite the difference of fortification time. Vitamin D-3 fortification time effect vitamin D-3 content, fat content, crude fiber, viscosity, and total lactic acid bacteria of goat milk kefir, but did not effect protein content and pH of goat milk kefir.