Purple sweet potato is a source of prebiotics that can be used in making synbiotic drinks by adding probiotics in the form of lactic acid bacteria (LAB), one of which is Lactobacillus plantarum 1 RN2-53. The purpose of this study was to obtain the best concentration of starter Lactobacillus plantarum 1 RN2-53 in the manufacture of purple sweet potato extract synbiotic drink. This study was cond…