Utilization of Air-classified Horse Gram (Macrotyloma uniflorum) Fractions for the Development of Nutritionally Tailored Composite Flour Mixes

Abstract

Horse gram (Macrotyloma uniflorum), an underutilised climate-resilient legume, was processed by air classification to obtain a protein-rich fine fraction (PRFHG) and a starch-rich coarse fraction (SRFHG) for the development of nutritionally tailored composite flour mixes. Cleaned, soaked, dried, roasted and milled horse gram flour was air-classified using an ATP-50 classifier operating at 7000 rpm and a feed rate of 0.3 kg h⁻¹. From 4.35 kg of feed material, PRFHG and SRFHG were recovered at 64.37% and 29.89%, respectively, resulting in an overall recovery of 94.25%. The fractions were incorporated at 10-50% levels into roti, pancake, porridge and pudding formulations and evaluated for sensory acceptability using a 9-point hedonic scale (n = 15) and for proximate composition using standard AOAC and IS methods. Roti containing 50% PRFHG exhibited the highest acceptability among protein-enriched products and showed a substantial increase in protein content from 10.58% to 26.84%, accompanied by reductions in carbohydrate and starch contents. Pancake containing 10% PRFHG achieved optimum sensory acceptance, with protein increasing from 9.48% to 12.96%. Among starch-enriched products, porridge containing 50% SRFHG and pudding containing 40% SRFHG recorded the highest sensory acceptability, with starch content increasing from 39.45% to 44.99% and from 44.73% to 54.49%, respectively. The findings indicate that air classification can generate nutritionally distinct horse gram fractions for developing protein-enriched and energy-dense food products with acceptable sensory quality, thereby supporting the value addition of underutilised legumes and the development of nutrient-dense functional foods.