Potential of Ganyong tuber starch (

Ganyong (Canna discolor) is a tuber plant with a relatively high inulin content, containing about 23.63% inulin per 100 g of starch flour. Inulin acts as a carbon and energy source that supports the growth and metabolic activity of lactic acid bacteria, thereby influencing the physicochemical properties of fermented milk. This study aimed to determine the effect of ganyong tuber starch flour addition on the quality of fermented goat milk using Lactobacillus rhamnosus. A completely randomized design (CRD) was applied with five treatments: 0% (P1), 1% (P2), 2% (P3), 3% (P4), and 4% (P5) ganyong starch flour, with four replications for each treatment, resulting in 20 experimental units. The parameters observed were pH, lactic acid concentration, and syneresis. Data were analyzed using Analysis of Variance (ANOVA), and Duncan’s Multiple Range Test (DMRT) was used to compare means when significant differences were found. The results indicated that the addition of ganyong starch flour significantly affected lactic acid concentration (p < 0.05) and had a highly significant effect on pH and syneresis values (p < 0.01). Among the treatments, the addition of 4% ganyong starch flour resulted in fermented goat milk with the highest lactic acid content, lower syneresis, and an appropriate level of acidity. In conclusion, ganyong starch flour can be effectively used as a natural source of inulin to improve the physicochemical stability and quality of fermented goat milk. This finding highlights its potential as a functional ingredient for the development of dairy products that meet consumer preferences and comply with the Indonesian National Standard (SNI 2981-2009).