Pengaruh Penambahan Pasta Ubi Jalar Ungu Terhadap Mutu Yoghurt

Abstract

The Ayamurasaki variety of purple sweet potato is one of the sweet potato cultivars that are widely grown in Indonesia. Purple sweet potato is known to contain non digestible oligosaccharides (NDOs) that can act as prebiotics for the development of probiotics in yoghurt making. This study was aimed to evaluate the effect of adding purple sweet potato paste on the physical, chemical, sensory quality, and growth of lactic acid bacteria in yoghurt. The model used in this study was a non-factorial Completely Randomized Design (CRD) with single factor of purple sweet potato paste addition. Parameters observed were viscosity, pH, total titratable acid as lactic acid, anthocyanin content, total sugar, color index (°Hue), total lactic acid bacteria, antioxidant activity (%inhibition), and organoleptic by hedonic value of color, aroma, taste, viscosity, and general acceptance. The results showed that the addition of purple sweet potato paste had a highly significant effect (P < 0,01) on the viscosity, pH, total titrable acid as lactic acid, anthocyanin content, color index (°Hue), total lactic acid bacteria, organoleptic by hedonic value of color, aroma, viscosity, and general acceptance of yoghurt. The best treatment obtained based on the De Garmo method was yoghurt with the addition of 10% purple sweet potato paste which had anthocyanin levels of 25.90 ppm, total lactic acid bacteria of 1.12×107 CFU/mL, and antioxidant %inhibition of 84.20%.