The effect of solar drying and heating on the hardness of Phaseolus beans during storage

Abstract

Small white beans ( Phaseolus vulgaris) were dried and heat processed before storage. Water removal in a solar drier was four times faster than conventional field drying in the pods. Heat treatments included particle-to-particle roasting using hot sand, and microwave heating. All samples stored for 212 days at low moisture contents (4–5%) showed a slow rate of hardening at a low temperature of 18°C and a high temperature of 34°C. However, heat treated and control beans became much harder when stored at a humidity of 9% and a temperature of 34°C. Heating and solar drying are effective treatments prior to bean storage, as they greatly reduce moisture to safer levels.