Effects of Seed Moisture Conditioning and Mechanical Scouring Pre-Treatments on Roller-Milled Green Lentil ( Lens culinaris ) and Chickpea ( Cicer arietinum ) Flours

The study evaluates the effect of pulse milling pre-treatments such as moisture conditioning and mechanical scouring on the compositional (moisture, protein, ash), functional (water-holding capacity), and physical (L*a*b* color, particle size distribution) properties of pulse flours. Two different types of pulses of pure cultivars, lentil ( Lens culinaris ) and chickpea ( Cicer arietinum ), were milled into flour using a laboratory-scale roller mill. Prior to milling, pulse seeds were subjected to two types of seed pre-treatments—(1) moisture conditioning (0%, 0.5%, or 1% w/w) and (2) mechanical scouring. The green lentils and chickpeas showed distinctive differences in all of the studied properties with pre-treatments. Moisture contents were higher in the scoured green lentil flours, while in the scoured chickpea flours were often lower within moisture conditioning levels. For many of the scoured flours, protein content was lower compared to the unscoured flours within moisture conditioning levels. Scouring was associated with higher L*a*b* color in the green lentil flours; however, for the chickpea flours, L*a*b* were less influenced by scouring. Green lentil middling and straight grade (SG) flours were more refined with scouring. Ash content and water-holding capacity values were not significantly different between the pre-treatment conditions for both pulse types. Differences in flour property results between pre-treatment conditions were significantly different ( P < 0.05) in the SG flours. These research findings could serve as a basis for the optimization and design of flour milling operations suitable for dry legumes and thereby improve the application of these high protein pulse flours in processed end-products to satisfy the desire for greater diversity in the food product market.