Polyphenolic Profile of Seed Components of White and Purple Flower Pea Lines

Polyphenols play roles in plant defense mechanisms and are natural sources of antioxidants in food. A pea (Pisum sativum L.) recombinant inbred line (RIL) population (PR-20) was developed from CDC Amarillo (white flower) and CDC Dakota (purple flower). Approximately half of the lines had white flowers and half had purple flowers, and these had two seed coat types (speckled and dun). The objective of this study was to use liquid chromatography coupled with mass spectrometry to compare polyphenolic profiles of seed components of four randomly selected PR-20 lines from each of these three distinct groups to identify polyphenols that can be targeted in pea breeding. We quantified 30, 29, and 27 polyphenols in whole seeds, seed coats, and cotyledons, respectively. Except for gallic acid in whole seeds, no differences were observed between speckled and dun seed coats. Compared with white flower lines, 24, 23, and 12 compounds were at greater concentration in seed coats (3-6100 times), whole seeds (2-820 times) and cotyledons (2-110 times) of purple flower lines. Cotyledons of purple flower lines contained eight times more 3,4-dihydroxybenzoic acid and 110 times more epigallocatechin than white flower lines. Ferulic acid, dihydrokaempferol, and kaempferol 3-O-glucoside were two to three times greater in cotyledons of white flower vs. purple flower lines. This study provides a basis for exploration of pea germplasm to identify accessions with high polyphenol content for breeding pea cultivars with improved health benefits in human diets.