The trypsin and chymotrypsin inhibitor activities of various pea (<i>Pisum</i> spp.) and field bean (<i>Vicia faba</i>) cultivars

Abstract

Abstract Eighteen pea and five field bean varieties were analysed for trypsin inhibitor activity. Considerable variation was found between pea varieties, the values ranging from 0.15 to 4.62 TIU mg −1 under the assay conditions used. However, all the pea varieties, with the exception of Progretta and Maro, had a lower trypsin inhibitor content than the average value (1.49 TIU mg −1 ) obtained for the field bean varieties. The same varieties were also examined for chymotrypsin inhibitor activity and again considerable inter‐varietal variation was found. Chymotrypsin inhibitor activity was significantly higher for all the pea varieties, with the exception of the variety Minerva, than that found for the field bean varieties. Both trypsin and chymotrypsin inhibitor contents appeared to be independent of crude protein content and other seed characteristics, and in both species these protease inhibitors were largely unaffected by dry heat but were rapidly denatured by autoclaving. The significance of these results with respect to the potential of improving nutritive value by plant breeding are discussed.