Functional properties of yellow field pea (Pisum sativum L.) seed flours and the in vitro bioactive properties of their polyphenols

Functional and bioactive properties of yellow field pea (Pisum sativum L) seed flour, protein isolate (PPI), two high fibre products (Centara III, Centara IV), and one high fibre–starch ingredient (Uptake 80), were determined. The whole seed flour had superior water and oil absorption capacities but the high fibre flours had significantly higher (p < 0.05) swelling ability. Centara IV and Uptake 80 had the highest gel clarity while Centara IV gel was the most resistant to freeze–thaw treatment. Polyphenolic constituents were extracted singly or sequentially with aqueous methanol and acetone; the whole pea seed flour and the pea protein isolate had significantly more polyphenolic constituents than the fibre products, which also resulted in higher in vitro antioxidant activities (trolox equivalent antioxidant capacity and diphenyl-picryl hydrazyl free radical scavenging ability). Results of renin- and ACE-inhibitory activities were mixed and did not correspond to the overall polyphenolic content and antioxidant test results, probably indicating the importance of components specific to individual extracts.