Subtopic: Drying and milling of cereals, pulses and oilseeds
Question Statement:
In the milling of pigeon pea (arhar / tur) into dhal, premilling conditioning involving application of vegetable oil ($1.5\text{ to }2.5\text{ g/kg}$) followed by water soaking and sun drying is performed primarily to:
Options:
(A) Loosen the seed coat (testa) bound strongly to the cotyledons by natural mucilaginous gums.
(B) Inactivate heat-labile trypsin inhibitors in the pulse cotyledons.
(C) Increase the moisture content to $35\%$ for wet extraction.
(D) Bleach the yellow carotenoid pigments in the split dhal.
Answer Key:
A
Step-by-Step Solution & Explanation
In pigeon pea and certain pulses, the seed coat is tenaciously bound to the cotyledons by a pectin and gum layer. The application of edible oil permeates between the husk and cotyledon, weakening the gum bonds. Subsequent water addition swells the cotyledons while sun drying contracts them, creating differential strain that detaches the husk cleanly during subsequent abrasive emery roller milling.