Enkapsulasi Lactobacillus casei dengan teknik ekstruksi sebagai starter untuk pembuatan dadih susu sapi

Abstract

The purpose of this research is to get an optimal composition for encapsulating materials of Lactobacillus casei as dried starter culture for production of dadih from cow milk. Lactobacillus casei was encapsulated by the extrusion technique, then dried by hot air oven on 40 oC. Biopolymer for encapsulating materials consist of sodium alginate and filler based on protein such as whey protein concentrate, sodium caseinate, and skim. The highest yield, the biggest diameter, and more spherical shape of beads was recorded in 4% alginate beads. Yield and diameter of beads decreased significantly with increasing filler concentration. Optimum proportion of alginate-filler on 4% total biopolymer is 2:1 (2.67% sodium alginate : 1.33% filler) that resulted in yield 78.7 – 80.7%, diameter 2.7 – 2.8 mm, and spherical – elliptical shape of beads. Encapsulated Lactobacillus casei in 4% alginate beads and alginate-skim 2:1 showed that the rate of acid produced was higher then alginatewhey 2:1 and alginate-sodium caseinate 2:1. Encapsulation of Lactobacillus casei with alginate-skim 2:1 resulted in a higher cell viability, namely 5.32 log cfu/gram or decline in viable count of about 2.36 log over a drying periode of 6 hour while there was a decline of about more than 5,76 log in Lactobacillus casei which were encapsulated with 4% alginate (without filler). Using dry starter (encapsulated Lactobacillus casei) for production of dadih from cow milk took longer time (48 hours) as compare to free cell (24 hours) on the same population of Lactobacillus casei. The characteristics of dadih from cow milk with dried starter application resulted in viscosity 2147 – 2563 cP, pH 5.55 – 5.75, titrable acidity 0.64 – 0.67%, and population of Lb. casei 8,16 – 8,43 log cfu/m . Population of Lactobacillus casei on dried starter in this study still low, namely 2.1 x 105 cfu/gram, and hence continuation experiments need to be increasing population of Lactobacillus casei in alginate-skim beads.