The effect of storage period on calcium and magnesium level and antimicrobial activity of goat's milk kefir

The purpose of this reasearch was to determine the effect of storage period goat’s milk kefir (GMK) on total LAB, total mineral levels included Ca and Mg and antimicrobial activity to pathogenic microbes. The materials used was GMK. This research was conducted using Completely Randomized Design with 4 treatments and 4 replications. The treatments were storage period that consist of D0 (0 day), D1 (7 days), D2 (14 days), and D3 (21 days). Total calculation of LAB used TPC (Total Plate Count). Samples were diluted from 10^-1 to 10^-8, then incoculated PCA medium by using pour plate method. Petri dish was incubated at 37ºC for 48 hours. Calcium and magnesium levels were calculed base AAS method. The result of this study was analyzed using analysis of variance (ANOVA), then followed by Duncan’s Multiple Range Test (DMRT). The storage time treatment has a significant effect on the total microbial count, mineral levels (Ca and Mg) and inhibition zone of Staphylococcus aureus, Escherichia coli and Salmonella enterica serovar typhi on goat's milk kefir. Average clear zone Staphylococcus aureus 2.60 – 3.18 mm. Average inhibition zone Escherichia coli 2.09 – 3.32 mm. Average clear zone Salmonella enterica serovar typhi 1.97 – 2.72 mm.