Modifikasi Pati Ubi Jalar Putih (Ipomoea Batatas-Linneaus) melalui Ikat Silang dengan Natrium Tripolifosfat

Abstract

Modification of sweet potato starch phosphate has been done through cross-linking reaction between white sweet potato starch (Ipomoea Batatas-Linneaus) with sodium tripolyphosphate (STPP). This research was conducted in two stages, the first stage was isolation of sweet potato starch and the second stage was cross-linking reaction with sodium tripolyphosphate with variations of 1%; 2%; 3% and variations of reaction time at 30, 60, and 90 minutes at a temperature of 45°C. The results of sweet potato starch isolation were analyzed using FT-IR spectrophotometer, surface morphology using SEM, degree of substitution test, swelling power test, solubility test, and viscosity test. Phosphate starch is a cross-linked modification using sodium tripolyphosphate, this is indicated by the FT-IR spectrum which shows a vibration peak at wave number 3265.1 cm indicating stretching of the OH group. The discovery of vibration at wave number 998.9 cm indicates the presence of P-O-C group supported by the absorption band of P = O aliphatic at wave number 1050-995 cm which is not found in sweet potato starch but is found in phosphate starch. Determination of the degree of substitution was carried out on all variations and the highest DS value was obtained in phosphate starch with a percentage variation of 3% with a reaction time of 1 hour,which was 0.263. Characterization of percentage variation phosphate starch with a reaction time of 1 hour produced a swelling power value = 7.24 g/g; solubility = 1.49%; and viscosity = 0.5884 cP. The results of morphological analysis of phosphate starch using SEM showed damaged/broken granule surfaces.