DETERMINING GELATINIZED STARCH IN A DRY STARCHY PRODUCT

Degree of gelatinization (DG) of starch in dry products was measured from the amount which dissolved in 0.2N KOH. The dissolved starch was complexed with 0.1N iodine and quantitated from absorption at 600 nm. When pregelatinized starch in KOH was the basis for the standard curve only 94% of added gelatinized starch mixed with raw starch was recovered. Recovery was 100% and coefficient of variation was <2% when absorbance of a blank was used to correct sample absorbance. The blank was prepared from the same mixture with only raw starch. The procedure adequately differentiated DG in several dry sweet potato-tapioca samples.