Kajian proses pembekuan dan daya simpan kultur bakteri laktat asal dadih untuk produksi kultur starter

Abstract

Dadih is a traditional fermented milk of West Sumatra - Indonesia, fermented in bamboo tube. Some srains of lactic acid bacteria isolated from Dadih possess probiotic properties; hence, it is important to study the effect of preservation of the lactic acid culture on their viability and biochemical properties during frozen storage. Four strains of lactic acid bacteria isolated from Dadih which have good antimutagenic properties are Lactococcus lactis subsp lactis R-22, Leuconostoc paramesenteroides R-51, Lactobacillus casei subsp casei R-52 and Leuconostoc paramesenteroides R-62. The lactic culture were preserved by freezing at -20°C by different freezing methods, frozen in deep freezer (slow freezing) and frozen in dry ice-ethanol mixture (fast freezing). Glycerol 10%, dimethylsulfoxide (DMSO) 10% and skim milk 10% were used as cryoprotectant with phosphat buffer pH 7,0 as control. The cultures were stored in deep freezer at -20°C as well as -70°C. The addition of glicerol 10% in Lactobacillus casei subsp, etc