Phenolic composition of the cotyledon and the seed coat of lentils (Lens culinaris L.)

The phenolic composition of the seed coat and the cotyledon of two varieties of lentils, Pardina and Castellana have been investigated by HPLC-photodiode array detection (PAD) and HPLC-MS. Large quantitative and qualitative differences have been found in the phenolic composition of the two seed parts. In both varieties of lentils the seed coat is very rich in catechins, procyanidins dimers and trimers, and in minor concentration it contains glycosides of quercetin, myricetin, luteolin and apigenin. The cotyledon contains mainly hydroxybenzoic and hydroxycinnamic acids in low concentration. Two esters of the trans-p-coumaric acid, p-coumaroylmalic acid and p-coumaroylglycolic acid have been identified in the cotyledon, and the stilbene trans-resveratrol-5-glucoside in the seed coat. These compounds had not previously been reported in lentils. Results presented allow an overview of the distribution of the phenolic compounds in the seed lentils, and contribute to knowledge of the implications in dietary intake of these compounds.