METHODS FOR DEHULLING OF PULSES - A CRITICAL-APPRAISAL

Pulses, the edible seeds of legumes, are dehulled into dhal (decorticated dry split cotyledons) for use as human. food. Not only does dehulling reduce cooking time and antinutrients, it also improves protein quality, palatability, and digestibility of pulses. An efficient and improved dehulling of pulses is of vital importance in reducing dehulling losses and thus increasing the availability of dhal in the daily diets of the people. In spite of several advances in dehulling methodology of pulses, dhal millers and villagers are still using the age-old traditional practices of dehulling, consequently incurring significant quantitative and qualitative losses. Dhal yield, which Is a function of dehulling efficiency, is highest in chickpea and lowest in pigeonpea in case of both small scale (stone chakki) and large scale (dhal mill) operations. Mean dehulling loss is nearly 33% in stone chakki and 25% in dhal mills. Of the various pretreatments, heating of seed before dehulling appears to improve the dhal yield in pulses, particularly in pigeonpea. Pulse varieties with uniform and round seeds are preferred for higher dhal yields. Genotypic differences exist in the dehulling characteristics of different pulses, as evaluated by using laboratory method. This paper reviews in-depth, several aspects of dehulling, such as methodology, pre-treatments, physical, morphological and chemical nature of seed, with respect to dehulling characteristics, nutrient losses and varietal, differences in dehulling quality.