HPLC Determination of Chlorophyll and Carotenoid Pigments in Processed Green Pea Cultivars (Pisum sativum L.)

Abstract

Chlorophyll and carotenoid pigments from six cultivars of processed green peas (Avola, Tristar, Rampart, Turon, Bella, and Greenshaft) were extracted with 100% acetone and analyzed by reversed-phase HPLC. A total of 17 pigments were identified in the pea cultivars including 8 xanthophylls ((all-E)-neoxanthin, (9‘Z)-neoxanthin, (all-E)-violaxanthin, neochrome, (all-E)-lutein epoxide, (all-E)-lutein, neolutein B, neolutein A), 4 chlorophyll b related compounds (chlorophyll b derivative, chlorophyll b, chlorophyll b‘, and pheophytin b), 4 chlorophyll a related compounds (chlorophyll a derivative, chlorophyll a, chlorophyll a‘, and pheophytin a), and (all-E)-β-carotene. The efficiency of different extraction procedures using 100% acetone showed that initial extraction followed by three reextractions without holding time between gave a higher extraction yield than no reextraction and 30 or 60 min holding time. All six cultivars contained the same pigments, but the concentration of each pigment varied significantly. On average of the two years, the chlorophyll a concentration varied from 4800 to 7300 μg/100 g fresh weight, the chlorophyll b concentration from 2100 to 2800 μg/100 g fresh weight, the (all-E)-lutein concentration from 1200 to 1900 μg/100 g fresh weight, and the (all-E)-β-carotene concentration from 300 to 490 μg/100 g fresh weight in the processed pea cultivars. These differences in pigment concentration between the investigated cultivars are discussed in relation to maturity, product color and nutritional quality. Keywords: Pisum sativum; chlorophylls; carotenoids; HPLC; extraction method; cultivars