The polyphenolic content and enzyme inhibitory activity of testas from bean (Vicia faba) and pea (Pisum spp.) varieties
Abstract
The polyphenolic content of the testa of two coloured flower varieties of beans grown in Wales was comparable with that of two coloured flower varieties of peas grown in eastern England. Testa tannins from both species had the same adverse effect on protein solubility, the inclusion of 15% testa producing a 7 unit reduction in protein solubility in 5% saline solution. Water extracts prepared from the testas also significantly inhibited in vitro the activities of trypsin, α-amylase and fungal cellulase, and in all cases enzyme activity was restored on the addition of polyvinyl pyrrolidone, clearly indicating that the observed inhibition was due to the presence of tannins. Analysis of the whole grain revealed that, due to differences in the proportion of testa (approximately 13% in beans as compared with 10% in peas), peas had a significantly lower overall polyphenolic content. However, it is concluded that pea testa tannins may be of equal significance to bean tannins in animal diets since the formulation of isonitrogenous diets would require a greater proportion of peas due to their lower protein content.
- Publication:
-
Journal of the Science of Food and Agriculture
- Pub Date:
- August 1981
- DOI:
- 10.1002/jsfa.2740320808
- Bibcode:
- 1981JSFA...32..797G