PATTERN OF ENZYME HYDROLYSIS IN RAW SAGO STARCH - EFFECTS OF PROCESSING HISTORY

Hydrolysis patterns of five batches of sage starch were studied by usi ng Novo Nordisk and Sigma alpha-amylases and glucoamylases. Native sag e starch was a poor substrate to the enzymes and the hydrolysis patter ns were surface erosion, pitting and crevassing. After incubation with pH 3.5 acetate buffer al 60 degrees C for 2 h, the hydrolysis pattern was different: a single deep round hole developed regardless of the b atch or enzyme(s) used. This step also significantly increased the deg ree of hydrolysis. Granule size distribution results indicated that at about 67% hydrolysis, treated granule residues were the same mean siz e as native granules while untreated granule residues had two major si ze populations. DSC results suggested that amorphous regions of the un treated granule were preferentially hydrolysed, however, upon pretreat ment regions within the granule were more uniform towards enzymes' act ion.