Effect of Ganyong (Canna discolor) Starch Addition as a Prebiotic on the Quality of Acidophilus Fermented Goat Milk

Ganyong (Canna discolor) belongs to the family Cannaceae and is one of the tuber crops containing 88.2% carbohydrates, with potential as a prebiotic due to its high inulin content. Ganyong tuber has a higher inulin content compared to other tubers, where 100 g of ganyong tuber contains 23.63% inulin. This study aimed to determine the effect of adding ganyong starch to goat milk fermented with Lactobacillus acidophilus on the quality of the fermented milk. The experimental design used was a Completely Randomized Design (CRD) consisting of five treatments: 0% (P1), 1% (P2), 2% (P3), 3% (P4), and 4% (P5) ganyong starch, with four replications for each treatment, resulting in 20 experimental units. The observed parameters were acidity (pH), lactic acid levels, and syneresis. The data obtained were statistically analyzed using Analysis of Variance (ANOVA), followed by Duncan Multiple Range Test (DMRT) if significant differences were found. The results showed that the addition of ganyong starch had a highly significant effect on pH and lactic acid levels (P<0.01), and a significant effect (P<0.05) on syneresis. Among the treatments, the addition of 2% ganyong starch produced fermented goat milk with lower acidity, the highest lactic acid levels, and reduced syneresis. In conclusion, ganyong starch in fermented goat milk can be effectively used as a source of inulin to support the growth of lactic acid bacteria, particularly Lactobacillus acidophilus. These findings highlight its potential as a natural ingredient for fermented milk products that are suitable for consumption and meet the Indonesian National Standard (SNI 2981:2009)