KUALITAS FISIKOKIMIA DAN MIKROBIA YOGHURT SINBIOTIK YANG DIBERI PATI TERMODIFIKASI UMBI UWI UNGU (Dioscorea alata) DENGAN LEVEL BERBEDA

Abstract

THE PHYSICOCHEMICAL AND MICROBIAL QUALITY OF SINBIOTIC YOGHURT GIVEN DIFFERENT LEVEL OF MODIFIED STARCH OF PURPLE UWI BULB (Dioscorea alata). An experiment was done in order to determine the level of modified starch of purple uwi bulb (Dioscorea alata) which best for syneresis, pH and total lactic acid bacteria of synbiotic yoghurt.  Completely Randomized Design (CRD) was used in this experiment with 6 treatments as follows P0 = yoghurt without modified starch purple uwi bulb, P1 = yoghurt + 0,1% modified starch purple uwi bulb, P2 = yoghurt + 0,2% modified starch purple uwi bulb, P3 = yoghurt + 0,3% modified starch purple uwi bulb, P4 = yoghurt + 0,4%  modified starch purple uwi bulb dan P5 = yoghurt + 0,5 modified starch purple uwi bulb; and three repetitions   each treatment. Measurements taken were syneresis, pH value, total of acid lactate bacteria. Data obtained were analyzed using ANOVA and Tuckey’s test was used to inspect treatment differences among group means.  It found in this research that application of modified starch of purple uwi bulb in symbiotic yoghurt gave a significant effect (P<0,01) on pH value and total lactic acid bacteria but not on syneresis. However, the syneresis values tendency decreased as the level of modified starch of purple uwi bulb increased.  The pH of symbiotic yoghurts given modified starch were ranged between 5.0 – 5.4 and the lowest pH was found in yoghurt with 0.3% modified starch added, meanwhile the total lactic acid bacteria of symbiotic yoghurts given modified starch were ranged between log ^10-78.65 – log^10-7 8.87 and the highest total lactic acid bacteria was found in yoghurt with 0.2% modified starch added.  It concluded in this research that the best quality of symbiotic yoghurt was in yoghurt with addition of modified starch of purple uwi bulb 0.3%.

 Keywords: Sinbiotic Yoghurt, Modified Starch of Ubi Purple Tuber, Sineresis, pH value, BAL Total