Genotype variation in BOAA, condensed tannins, phenolics and enzyme inhibitors of grass pea (Lathyrus sativus)

Abstract

Genotypic variability in the neurotoxin, beta-N-oxalyl-amino-L-alanine (BOAA), condensed tannins and phenolics, and protein inhibitors of trypsin, chymotrypsin and alpha-amylase was investigated in 100 lines of Lathyrus sativus (grass pea) germplasm maintained at the Morden Research Station. The ranges for these antinutrients (overall means in the parentheses) were as follows: BOAA 0.22–7.20 (2.95) g kg−1, condensed tannins 0.0–4.38 (1.17) g kg−1, trypsin inhibitor 133–174 (155) units mg−1, chymotrypsin inhibitor 0–23 (10) units mg−1, and alpha-amylase inhibitor 3.6–91.4 (35.2) units g−1. Condensed tannins were positively correlated with the seed coat pigmentation, with coloured genotypes containing greater levels of tannins. The wide range in condensed tannins suggests that selection for low levels of this antinutrient should be feasible. Whereas the low levels of chymotrypsin and amylase inhibitors in L. sativus may not pose any serious problems in animal and human nutrition, further screening of a larger germplasm is required to identify genotypes containing low/no levels of the trypsin inhibitor.Key words: Lathyrus sativus, tannins, phenolics, enzyme inhibitors, grass pea, BOAA