Antioxidant Activities and Characterization of Polyphenols from Selected Northern Thai Rice Husks: Relation with Seed Attributes

• Published in: Rice science Vol. 30; no. 2; pp. 148 - 159
• Main Authors: Wisetkomolmat, Jiratchaya, Arjin, Chaiwat, Hongsibsong, Surat, Ruksiriwanich, Warintorn, Niwat, Chutamat, Tiyayon, Pimsiri, Jamjod, Sansanee, Yamuangmorn, Supapohn, Prom-U-Thai, Chanakan, Sringarm, Korawan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2023; Lanna Rice Research Center,Chiang Mai University,Chiang Mai 50200,Thailand%Department of Animal and Aquatic Sciences,Faculty of Agriculture,Chiang Mai University,Chiang Mai 50200,Thailand; Cluster of Research and Development of Pharmaceutical and Natural Products Innovation for Human or Animal,Chiang Mai University,Chiang Mai 50200,Thailand%Food Science and Technology Program,School of Agro-Industry,Mae Fah Luang University,Chiang Rai 57100,Thailand%School of Agricultural Resources,Chulalongkorn University,Bangkok 10330,Thailand%Agronomy Division,Department of Plant and Soil Sciences,Faculty of Agriculture,Chiang Mai University,Chiang Mai 50200,Thailand%Lanna Rice Research Center,Chiang Mai University,Chiang Mai 50200,Thailand%Agronomy Division,Department of Plant and Soil Sciences,Faculty of Agriculture,Chiang Mai University,Chiang Mai 50200,Thailand; Lanna Rice Research Center,Chiang Mai University,Chiang Mai 50200,Thailand; Cluster of Research and Development of Pharmaceutical and Natural Products Innovation for Human or Animal,Chiang Mai University,Chiang Mai 50200,Thailand; Department of Animal and Aquatic Sciences,Faculty of Agriculture,Chiang Mai University,Chiang Mai 50200,Thailand%School of Health Science Research,Research Institute for Health Sciences,Chiang Mai University,Chiang Mai 50200,Thailand%Department of Pharmaceutical Sciences,Faculty of Pharmacy,Chiang Mai University,Chiang Mai 50200,Thailand; Elsevier
• Subjects: agri-waste; antioxidant; polyphenol; rice husk; seed characteristic; Thai rice; seed characteristic; antioxidant; polyphenol; Thai rice; rice husk; agri-waste
• ISSN: 1672-6308; 1876-4762
• DOI: 10.1016/j.rsci.2023.01.007

Rice production generates a significant amount of agricultural waste. This study aimed to give results related to the existence of antioxidant phenols in agricultural waste of selected Northern Thai rice varieties. The antioxidant activities, contents of total flavonoids and phenolic compounds in the ethanolic rice husk extract were evaluated. The highest antioxidant activities were found in the variety PES1CMU, with 2,2ʹ-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid and 2,2-diphenyl-1-picrylhydrazyl as 679.66 and 4.16 mmol/(L·g) trolox equivalent, respectively, ferric reducing antioxidant power as 0.87 mmol/(L·g) Fe2+, total phenolic content as 29.90 mmol/(L·g) gallic acid and total flavonoid content as 12.16 mg/g catechin equivalent. Polyphenol compounds were identified mainly by standard polyphenols using the liquid chromatography mass spectrometry, with the highest contents of phytic acid, o-coumaric acid, naringin and kaempferol. The non-glutenous and wetland ecotypes of rice husk samples were the richest in antioxidant activities and polyphenol contents characterized by using principal component analysis. The glutenous rice husk contained higher antioxidant activities than the rest. Interestingly, quercetin is a significant phenolic compound that positively correlated with the overall antioxidant activities of rice husk. This finding will be relevant for future application of rice husk antioxidant components in the production of functional ingredients as well as for the food and pharmaceutical industries.