Proximate composition, phenolic profiles and antioxidant capacity of three bean varieties (Dimeta, Napirira and Nanyati) were investigated. There were significant (p < 0.05) differences among varieties in all proximate components. Dimeta bean had the highest content of crude fat, and free and bound phenolic compounds, while Nanyati bean had the highest content of ash and carbohydrate. Napirira bean had the highest content of crude protein and all phytochemicals, as well as the oxygen radical absorbance capacity (ORAC). The phenolic compounds existed mainly in the free form as detected by high performance liquid chromatography (HPLC). A total of five phenolic compounds (protocatechuic, p-hydroxybenzoic, p-coumaric, ferulic and sinapinic) were found in these bean varieties while catechin was only detected in Napirira bean. The anthocyanins in these three bean varieties were detected by HPLC-MS. Delphinidin 3-O-glucoside, cyanidin 3-O-glucoside and pelargonidin 3-O-glucoside were the main anthocyanins in Dimeta bean, while cyanidin 3-O-glucoside, pelargonidin 3-O-glucoside and pelargonidin derivatives were the major anthocyanins in both Napirira and Nanyati beans. It could be concluded that significant differences in proximate composition, phenolic profiles and antioxidant capacity occurred among the three varieties with Napirira bean showing superiority as a functional food ingredient.
Citation: Fan G, Beta T. 2016. Proximate Composition, Phenolic Profiles and Antioxidant Capacity of Three Common Bean Varieties (Phaseolus vulgaris L.). J Food Chem Nanotechnol 2(3): 147-152.