Characterization of Bioactive Compounds in Whole, Dehulled and Fractions of Milling Byproducts of Lentil

Abstract

Aims: The development of convenient food products including nutrient-dense pulses along with cereals, make it complete food by integrating complementary proteins present in cereals and pulses. Lentils are major pulse, which is often consumed after dehusking to enhance culinary and functional properties. Abrasive dehusking surfaces cause scouring of outer layer of cotyledons, which gets mixed with husk to produce milling byproduct in the process. To explore the possibility of edible usage lentil milling byproduct, bioactive compounds present in whole lentil, dehusked lentil and milling byproduct and its fractions, were studied for two lentil varieties, IPL-406 and IPL-316. Study Design: Analysis of samples of whole, dehusked and milling byproduct fractions. Place and Duration of Study: ICAR-Indian Institute of Pulses Research, Kanpur 208 024 (U.P.), India. December 2018 to March, 2022. Methodology: In the study physical and biochemical attributes were determined. Milling byproduct was fractionated to the particle sizes categories of >1.00 mm, >0.25 mm, and <0.25 mm. Physical properties, viz., moisture content, 1000 grain weight, average and geometric mean diameter, sphericity, bulk density, true density, angle of repose and coefficient of static friction, which play important role in designing of equipment, were determined. The biochemical compounds viz., protein, total phenol, antioxidants and calorific value of whole and dehusked lentils, byproduct and its fractions, were assessed for their food value. Results: The largest fraction of milling byproduct (>1 mm) for the varieties had high phenols (5701.04 and 5447.62 GAE/100g) and antioxidants (190.59 and 210.41 mmol TE/100g). The finest fraction of lentil milling byproduct (<0.25 mm), exhibited the highest protein content in both varieties, recorded to be 25.05% in IPL-406 and 22.64% in IPL-316. Principal Component Analysis (PCA) was employed to elucidate correlations among the measured variables, providing insight into the relationships between physical properties and nutrient distribution in the milling fractions. Conclusion: Lentil milling byproduct rich in fibers, phenols and antioxidant can be utilised to develop value added products with nutritive and therapeutic usage.