EFFECT OF MOISTURE-CONTENT ON COMPRESSIVE STRENGTH OF WHOLE SNAP BEAN(PHASEOLUS-VULGARIS L) SEEDS AND SEPARATED COTYLEDONS

The compressive strength and force of three cultivars of whole snap be an (Phaseolus vulgaris L.) seeds and cotyledon sections were measured over a range of water activity from 0.45 to 0.65 in 0.1 increments. Co mpressive strength was measured with a flat platen for whole bean comp ression and with a 1 mm diameter cylindrical probe for cotyledon stren gth tests, At high moisture content seeds had a plastic behaviour. The compressive force for seed breakage increased with increasing moistur e content, and the breeding line NY537-Dark was the most resistant to fracture. Cotyledon compression strength decreased with increasing moi sture content regardless of seed coat presence.