Optimizing anthocyanins extraction and the effect of cold plasma treatment on the anti-aging potential of purple glutinous rice (Oryza sativa L.) extract

Abstract

Background and objectives: The pericarp of color rice is a rich source of anthocyanins conferring several health benefits. The present study aimed to systemically optimize anthocyanins extraction from Thai purple glutinous rice and to elucidate the effect of cold plasma on the anti-aging effect of the extract. Findings: Antioxidant effects and phytochemical constituents of the extracts from three Thai purple glutinous rice varieties including Doi Saket, Phayao, and Luem Pua were elucidated. Cyanidin-3-O-glucoside (CNG) was a major compound in all varieties. Besides, Luem Pua rice extract presented the strongest antioxidation owing to its highest total phenolic and CNG contents. The optimized method for extracting CNG, which was proceeded by 2-level full factorial design, used deionized (DI) water with pH 2.0 and temperature 150°C. Moreover, the cold plasma-treated Luem Pua rice offered a five-fold higher amount of CNG compared to the untreated sample with a significantly stronger anti-aging potential. Conclusions: Our study provided the optimized method for CNG extraction from purple rice. Additionally, cold plasma potentially enhanced the anti-aging property of the extract. Significance and novelty: The contributions of the extracting factors on antioxidation and anthocyanins content were statistically elucidated, and the novel performance of cold plasma on biological properties of the plant materials was demonstrated.