Trypsin inhibitors and phytic acid in oil-extracted meals from seeds of several Brassica species and of Sinapis alba

Abstract

A total of 124 seed samples representing strains and cultivars of Brassica napus, B. rapa, B. juncea, B. carinata, and Sinapis alba were selected for assays of trypsin inhibitor (TI) and phytic acid (PA). On an oil-extracted basis the TI values ranged from 1.26 to 5.31 units g-1. Values for B. napus ranked highest (3.58, 3.61) and B. juncea lowest (1.26, 1.39, 1.56) (P < 0.05). In a comparison of PA in three cultivars (B. napus, B. rapa, B. juncea), the cultivars differed in PA contents (2.52, 2.94, 2,70, respectively), there were no year-to-year differences over 4 yr (2.56, 2.67, 2.68 vs. 2.96) but there were significant location effects (2.12, 2.21 vs. 3.04, 3.42). In a set of 10 cultivars replicated three times, B. juncea PA contents (3.35-3.91) exceeded those of B. napus (2.92, 3.06), and B. carinata (2.72, 3.15). Sinapis alba had the lowest value (2.49). Bronowski (B. napus), the gene source of all low glucosinolate cultivars, contained the most TI (5.31 units g-1) and the least PA (1.93%).