The Impact of Heat Transfer on Glucose Generation and Degradation with Instant Heating and Slow Heating Technologies

Abstract

The impact of fast heating and slow heating during non-isothermal stage in hydrolysis of crude sago starch into glucose was compared between two systems: DIC system with direct steam injection on material against DAH system with external heating source. Heating process; glucose and glucose degradation products were quantified and modelled after the first order kinetic reaction. Rate constant; h for heating was obtained from numerical model fitted into kinetic data. hDIC was 45 min-1 and 33 min-1 at 130°C and 150°C respectively; while hDAH was 0.565 min-1 and 0.725 min-1 at respective temperature. Relative rate hDIC/hDAH was 79.7 and 45.5 at respective temperature. Glucose generation rate during non-isothermal stage was 6.0 mg/s and 1.03 mg/s for respective DIC and DAH system. Total glucose degradation products during level-off temperature at end of non-isothermal stage was 0.4 mg (DIC) and 20.5 mg (DAH). It is concluded that DIC system having potential as a pre-treatment system to optimize glucose generation while controlling its degradation.