Tannins were analyzed on three cultivars of cowpeas at three maturity
stages. Cultivars differed in testa darkening which increased during m
aturation. Darker testa had greater tannin concentrations. Testa tanni
ns increased up to 7-fold during maturation and up to 96% of the tanni
ns were found in the tesla. The sum of tannins in individually tested
cotyledon and testa was up to 10.7 times greater than that found from
analysis of whole cowpea after grinding to 20-mesh. Heating in water r
educed whole cowpea tannins 38-76%; cotyledon 53-59%, and testa 66-75%
.