title: Effect of acid pretreatment and the germination period on the composition and antioxidant activity of rice bean (Vigna umbellata).
abstract: This research evaluated effect of germination period and acid pretreatment on chemical composition and antioxidant activity of rice bean sprouts. Moisture, total phenolics, reducing sugar and B vitamins (thiamine, riboflavin, and niacin) content of steamed sprouts increased with increasing germination time (p⩽0.05). Pretreatment with 1% (w/v) citric acid for 6h significantly increased the total phenolic content. The 18-h-germinated rice beans showed the highest crude protein content, as determined using the Kjeldahl method. During germination, acid pretreatment led to a significant decrease in the intensity of the 76-kDa band. Germination caused a significant increase in radical scavenging activity and ferric reducing antioxidant power, especially in sprouts from citric acid-treated seeds. The antioxidant activities of the ethanolic extracts from both pretreated beans and the control were 1.3-1.6 times higher than those obtained from the water extracts. Major phenolics found in both 0-h and 18-h-germinated rice beans were catechin and rutin.
authors.affiliation: Department of Food Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Burachat
authors.initials: B
authors.lastname: Sritongtae
authors.affiliation: Department of Food Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Thasanporn
authors.initials: T
authors.lastname: Sangsukiam
authors.affiliation: School of Food Science and Nutrition, University of Leeds, United Kingdom.
authors.forename: Michael R A
authors.initials: MR
authors.lastname: Morgan
authors.affiliation: Department of Food Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand. Electronic address: kiattisak.d@chula.ac.th.
authors.forename: Kiattisak
authors.initials: K
authors.lastname: Duangmal
mesh_terms: D000143:Acids / Q000494:pharmacology*; D000975:Antioxidants / Q000032:analysis / Q000378:metabolism*; D018525:Germination / Q000187:drug effects*; D010636:Phenols / Q000032:analysis / Q000378:metabolism; D012639:Seeds / Q000737:chemistry / Q000187:drug effects / Q000254:growth & development; D000070658:Vigna / Q000737:chemistry / Q000187:drug effects / Q000254:growth & development*
chemical_list: D000143:Acids; D000975:Antioxidants; D010636:Phenols
keywords: Amino acid profile; Antioxidant activity; Germinated bean; Rice bean; Sprouts; Vigna spp.