COMPARISON OF TRADITIONAL AND ULTRASONIC-ASSISTED EXTRACTION METHODS ON ANTHOCYANIN, TOTAL PHENOLIC COMPOUNDS AND ANTIOXIDANT ACTIVITY OF HOMDAENG ST.1 AND HOMDUM ST.2 BROWN RICE

Abstract

Variety of bioactive compounds with health benefits have been discovered in pigmented rice. This research aims to study the effects of extraction methods on biological active compounds of Homdaeng ST.1 and Homdum ST.2 brown rice. Both types of brown rice were extracted using conventional and ultrasonic-assisted extraction techniques to examine the most effective method of extracting their active compounds. The ultrasonic extraction method of Homdum ST.2 extract provided the highest yield of 2.45%, while traditional extraction method of Homdaeng ST.1 extract gave the lowest value amounted of 1.06%. Anthocyanin content was determined by pH-differential method. Antioxidant capacity was measured by DPPH method and total phenolic compounds were evaluated by Folin–Ciocalteu colorimetric. It was found that the ultrasonic extraction method of Homdum ST.2 exhibited the highest anthocyanin content of 9.128 mg/L. However, the highest antioxidant activity was shown in traditional extraction method of Homdaeng ST.1, exhibiting 201.556 µg BHT/ml, and IC₅₀ value of 12.089 µg /ml. Moreover, the traditional method of Homdaeng ST.1 exhibited the highest total phenolic compound of 149.98 mg GAE/g extract. The findings of this study might help in considering the type of extraction techniques for Homdaeng ST.1 and Homdum ST.2 brown rice to be used as ingredients in supplements, as well as in functional foods.