Comparison of Enzymatic Hydrolyses of 4 Kinds of starch

Abstract

Heat stable amylase (Novo Industri) was used in enzyme hydrolysis of rice starch, waxy rice starch, corn starch and cassava starch. Hydrolysis conditions were 35% starch, 0.1% enzyme, temperature 75, 80, 85 and 90°C, time 30, 60, 90 and 120 mins. The results show that at 75°C, the highest liquefied starch was obtained from cassava starch and the lowest from ricr starch. At higher temperature, all 4 kinds of starch gave out higher liquefied starch. The maximum liquefied starch from rice starch and waxy ricr starch was 90%, while from corn starch and cassava starch was 98%. At 75°C, waxy ricr starch was hydrolysed to yield the highest reducing agent, followed by cassava starch, corn starch and rice starch, respectively. Reducing agents increased with temperature, and showed no differences at 85 and 90°C. Reducing agents from cassava starch were higher than that from waxy rice starch at 85 and 90°C 120 min. Dextrose equivalent (DE) from hydrolyses at studied conditons ranged from 19 to 49 depending on starch, temperature and time. There was difference in digestion pattern. Rice starch and waxy rice starch were hydrolysed by enzymes to small molecular saccharides (DP1-DP7) faster than corn starch and cassava starch. The different saccharide contents were obserued. The highest small saccharides were DP2 and DP3, the moderate ones were DP4, DP5 and DP6, and the lowest ones were DP1 and DP7 from waxy rice starch.