Antioxidant activities of Thai pigmented rice cultivars and application in sunflower oil

Abstract

Summary An analytical comparison for active chemical compounds and their antioxidant activities between three representative pigmented Thai rice cultivars was performed. It was revealed that the darkest purple‐red cultivar (Kum Doi Musur, KDM) contained the highest total phenolic content of 1164.6 mg gallic acid equivalent per100 g (dry basis, db) and the highest total monomeric anthocyanin content of 381.7 mg per100 g (db), when compared with the purple cultivar (Riceberry) and the red cultivar (Sungyod). Its 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging activity and ferric reducing antioxidant power were also the highest. When applied in sunflower oil, the KDM crude extract was efficiently capable of retarding lipid peroxidation as assessed by peroxide value, p‐anisidine value, totox value and the Rancimat method. Results show this specific pigmented rice to be a potent antioxidant for stabilisation of sunflower oil.

Effect of Preparation Method on Chemical Property of Different Thai Rice Variety

“…Table 2 shows that TAC in RB was higher in non-polished samples and the effect was more pronounce in parboiling treatment. This result confirms that rice bran is the source of anthocyanin in RB as has been reported previously [37]. Similarly, the highest TPC content was also observed in RB.…”

Coeliacs cannot live by gluten‐free bread alone – every once in awhile they need antioxidants

“…Anggraini et al (2015) showed that the rice colour presented a correlation with the antioxidant activity for red and purple rice, the darker the colour of rice, the higher the antioxidant activity. These results are in well harmony with those reported for Thai pigmented rice cultivars (Daiponmak et al, 2014;Chinprahast et al, 2016). Mir et al (2016) and Liu et al (2015) demonstrated that brown rice contains a significant amount of antioxidants by the determination of the total polyphenol content, the total flavonoid content and the antioxidant activity of different varieties of brown rice.…”

“…The colour of the pericarp is mainly related to the type and concentration of the polyphenols in the rice grain (Kim et al, 2014a). These results are in well harmony with those reported for Thai pigmented rice cultivars (Daiponmak et al, 2014;Chinprahast et al, 2016). In the last years, some studies have been published that assess the polyphenols content and antioxidant capacity of rice as function of the different rice colour variety (Table 1).…”

Evaluation of antioxidant properties of the different tissues of vine tea (Ampelopsis grossedentata) in stripped canola oil and sunflower oil

“…Also, some plants extract containing flavonoids or polyphenols have been applied to edible oil, negatively affecting oxidation (Sekhon‐Loodu et al., 2013; Ye et al., 2015). However, the antioxidant effect of anthocyanins in oil system is relatively poor, compared with flavonoids or polyphenols (Chinprahast, Tungsomboon, & Nagao, 2016; Shantha & Decker 1994). Likewise, the crude extract of dark purple–red rice cultivar showed some ability to prevent lipid peroxidation, whereas its activity is inferior to that of BHA; BHT outperforms BHA in inhibiting biodiesel oxidation (Domingos et al., 2007).…”