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 bean (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. Compressive strength was measured with a flat platen for whole bean compression and with a 1 mm diameter cylindrical probe for cotyledon strength tests, At high moisture content seeds had a plastic behaviour. The compressive force for seed breakage increased with increasing moisture content, and the breeding line NY537-Dark was the most resistant to fracture. Cotyledon compression strength decreased with increasing moisture content regardless of seed coat presence.