Effects of Treatment Time during Subcritical Water Treatment and Its Re-treatment on the Properties of Rice Stem Extract

Abstract

Rice stem was treated with subcritical water at 260ºC for 0-20 min. The extracts treated for 5 min were subject to re-treatment for 0-60 min. In the further treatment, the total phenolic content, total carbohydrate content, radical scavenging ability, and metal chelating ability decreased with extended treatment time. Tyrosinase inhibition ability, however, did not depend on the treatment time. There were correlations between the total phenolic content and radical scavenging ability and between the total carbohydrate content and metal chelating ability under any treatment conditions.

Engineering aspects of rate-related processes in food manufacturing

“…The extended treatment gave lower total phenolic and carbohydrate content, radical scavenging ability, and metal chelating ability over time, while correlations were observed between total phenolic content and radical scavenging ability and between total carbohydrate content and metal chelating ability for all conditions. 141) Finally, the stems were subjected to subcritical fluid treatment at 230°C using ethanol and acetone with a complete range of dilution in water. The highest general and carbohydrate yields were achieved with subcritical 20% (v/v) organic solvents, while the highest phenolic content was obtained with subcritical 80% (v/v) acetone.…”