| dc.description.abstract | Modification of breadfruit starch oxalic was carried out through a cross- linking reaction between breadfruit starch (Artocarpus altilis) and oxalic acid. This research was conducted in two stages, namely isolation of breadfruit starch and cross- linking reaction with oxalic acid with variations in oxalic acid concentrations of 10%, 20%, 30%, 40%, and 50% (%w/w) of the starch mass and variations in the stirring time of 1 hour, 2 hours, and 4 hours. The starch obtained from the isolation of 35 kg of breadfruit is 5,5 kg (15,7%) of breadfruit starch. The resulting oxalic acid cross- linked starch is a white powder. The resulting cross-linked starch was analyzed for functional groups using an FT-IR spectrophotometer, the appearance of a wave number of 1729 cm indicated the vibrational region of C=O ester. The percentage of oxalate and degree of substitution obtained ranged between 1,2154%-14.4048% and 0,02213-0,30225 with the highest percentage of oxalate and degree of substitution showing the optimum variation, at variations of 40% oxalic acid concentration with a stirring time of 2 hours namely 14,4048% and 0,30225. The results of the characterization of oxalic crosslinked breadfruit starch with varying concentrations of oxalic acid 40% to mass with a stirring time of 2 hours were as follows: swelling power 2,292 g/g: starch solubility in distilled water 13,02%; starch solubility in dimethyl sulfoxide (DMSO) 59,66%: and viscosity 2.17 mP. The results of the morphological analysis of oxalic cross-linked starch using SEM showed that the granule shape was irregular globular in shape and the granule shape was denser than breadfruit starch. | en_US |
