Syrup production via enzymatic conversion of a byproduct (broken rice) from rice industry

摘要

In a hydrothermal process for the gelatinization of the rice starch, it was studied the rate of hydration, temperature and time. An incomplete 3 3 factorial design was used to evaluate the effects of temperature, enzyme/substrate relation and liquefac tion time, with dextrose equivalent (DE) as the response variable. The maximum value obtained was 14. 69% DE at 89oC, with 0.21% (w/w) of enzyme to substrate in 22 minutes. For saccharification, it was st udied enzyme/substrate ratios (0.6, 2.4, 4.2 and 6.0% (w/w)) at 60oC at a pH of 4.30, yielding 49.23, 69. 65, 65.12 and 74.67% DE, respectively, after 72 hours. The syrup had a content of 12.78, 16.87, 15.96 and 17.87% of glucose (w/v), pH 2.60 - 2.71. The starch content converted into glucose after liquefaction was 61.80% and after saccharification ranged from 75.16 to 77.05% for the relation enzymes substrate tested.