Bitterness of saponins and their content in dry peas

The bitterness of a saponin mixture (containing saponin B and DDMP (2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one) saponin in a ratio of 1:4) and saponin B obtained from dry peas were established by a trained panel using line scaling. Both saponins were found to be bitter. However, the saponin mixture, and hence DDMP saponin, was found to be significantly more bitter than saponin B. The bitterness perceived correlated with the saponin concentration. In addition to saponin bitterness, the saponin content and composition of 16 dry pea varieties were also investigated. In two varieties, DDMP saponin was the only saponin present whereas, in the rest of the varieties, DDMP saponin was more abundant than saponin B. The pea varieties investigated differed significantly in saponin content. The amounts of DDMP saponin ranged from 0.7 to 1.5 g kg-1 (dry matter), whereas those of saponin B ranged from 0 to 0.4 g kg-1. As saponins are bitter, pea varieties with lower saponin contents would be preferred for use in food production