Antioxidant Compounds and Antioxidant Activities of Ethanolic Extracts from Brown Rice Cultivars

현미 품종별 에탄올 추출물의 항산화 성분 및 항산화 활성

Abstract

This study investigated chemical components, antioxidant compounds, and activity of brown rice cultivars, to select good cultivar to be used for processing of mixed-rice in the food industry. Proximate compositions, phytic acid, phenolic compounds, and antioxidant activity of brown rice were significantly different among cultivars. Moisture, crude ash, fat, protein, and carbohydrate contents of brown rice were 9.51~12.82, 1.05~1.93, 1.84~6.24, 5.90~9.60 and 71.75~80.34 g/100 g, respectively. Phytic acid content of brown rice cultivars was 7.39~0.87 mg/g. Total polyphenol content of Joeunheukmi and Geonganghongmi cultivars, were 615.25 and $311.14{\mu}g\;GAE/g$, total flavonoid content was 267.75 and $100.67{\mu}g\;CE/g$, respectively. DPPH radical scavenging activity of Geonganghongmi, Joeunheukmi and Hyeugkwang cultivars was 89.17, 87.94 and 43.17%, ABTS radical scavenging activity was 113.57, 113.34, and $93.53{\mu}mol\;TE/g$, and ferric reducing antioxidant potential was 951.67, 1,075.75, and $508.33{\mu}M/g$, respectively. As a result, phenolic compounds and antioxidant activities of pigmented brown rice were high, and it could be used as a functional material.

Fig. 1. Phytic acid contents of brown rice cultivars.

Fig. 2. Total polyphenol and flavonoid contents of ethanolic extracts on the brown rice cultivars.

Fig. 4. The ferric reducing antioxidant potential (FRAP) of ethanolic extracts on the brown rice cultivars.

Table 1. The proximate compositions of brown rice cultivars

Fig. 3. DPPH and ABTS radical scavenging activity of ethanolic extracts on the brown rice cultivars.

Table 2. Correlation coefficients among proximate compositions, phytic acid, total polyphenol (TPC), flavonoid contents (TFC), radical scavenging activity, and FRAP of brown rice cultivars