In vitro Antioxidant Activity of Cooked Rice Containing Various Seaweeds

摘要

An emerging interest in healthy eating has led to an increase in the consumption of rice mixed with various types of grains. Cooked rice was prepared with five different seaweeds, Hizikia fusiformis, Sargassum fulvellum, Enteromor-pha compressa, Undaria pinnatifida, and Gracilaria verrucosa, and the antioxidant activity was measured. In addition, the antioxidant activities of 80% ethanol and methanol extracts of the five seaweeds were compared. Total phenolic content (TPC), total reducing power (TRP), 2,2-diphenyl-l-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenz-thiazoline-6-sulphonic acid (ABTS) cation radical scavenging activities of the ethanol extracts were higher than those of the methanol extracts. The TPC of raw seaweed ethanol extractswas from 7.58 to 26.27 mg gallic acid equivalent (GAE)/g. The antioxidant activities of both extracts of Hizikia fusiformis were the highest among the five seaweeds, and the antioxidant activities of the cooked rice were lower than those of the raw seaweed extracts. The DPPH radical scavenging activities of cooked white rice, mixed grains, barley, and a mixture of white rice and barely added with Hizikia fusiformis, Sargassum fulvellum and Undaria pinnatifida were 3.17, 23.12, 31.11 and 10.66%, respectively. These results demonstrate the addition of seaweeds to cooked rice helps to improve the antioxidant activity compared to white rice alone.