Comprehensive understanding of roller milling on the physicochemical properties of red lentil and yellow pea flours

Authors: PULIVARTHI, MANOJ KUMAR - Kansas State University; NKURIKIYE, ERIC - Kansas State University; WATT, JASON - Kansas State University; LI, YONGHUI - Kansas State University; SILIVERU, KALIRAMESH - Kansas State University

Submitted to: Processes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/11/2021
Publication Date: 10/15/2021
Citation: Pulivarthi, M., Nkurikiye, E., Watt, J., Li, Y., Siliveru, K. 2021. Comprehensive understanding of roller milling on the physicochemical properties of red lentil and yellow pea flours. Processes. 9(10). Article 1836. https://doi.org/10.3390/pr9101836.
DOI: https://doi.org/10.3390/pr9101836

Interpretive Summary: Consumer demand for healthier food choices has been growing and includes an interest in nutrient-rich functional foods, such as those containing pulses like peas and lentils. However, the development of new food products containing pulse ingredients is limited by a standard milling method for generating high-quality pulse flours from raw peas and lentils. In this study, we used different roller mill settings to produce small, medium, or large yellow pea or red lentil flours. Differences in chemical composition, physical characteristics, and particle size distributions of the resultant flour fractions were also characterized. Overall, the mill settings had a significant effect on the physical properties of different particle-sized flours, but the chemical composition of the flour types remained practically the same. The results will assist millers, who normally process cereals, in determining how best to modify their milling facilities to accommodate pulse grains. The study will also help boost the use of pulse ingredients in various baking products to enhance their nutritional quality.

Technical Abstract: The development of convenience foods by incorporating nutrient-rich pulses such as peas and lentils will tremendously alter the future of pulse and cereal industries. However, these pulses should be size-reduced before being incorporated into many food products. Therefore, an attempt was made to adapt roller mill settings to produce de-husked yellow pea and red lentil flours. The milling flowsheets unique to yellow peas and red lentils were developed in producing small, medium, and large flours with maximum yield and flour quality. This study also investigated the differences in chemical composition, physical characteristics, and particle size distributions of the resultant six flour fractions. The kernel dimensions and physicochemical properties of the whole yellow pea and red lentils were also studied to develop customized mill settings. Overall, the mill settings had a significant effect on the physical properties of different particle-sized flours. The geometric mean diameters of different particle-sized red lentil flours were 56.05 µm (small), 67.01 µm (medium), and 97.17 µm (large), while for yellow pea flours they were 41.38 µm (small), 60.81 µm (medium), and 98.31 µm (large). The particle size distribution of all the flour types showed a bimodal distribution, except for the small-sized yellow pea flour. For both the pulse types, slightly more than 50% flour was approximately sizing 50 µm, 75 µm, and 100 µm for small, medium, and large settings, respectively. The chemical composition of the flour types remained practically the same for different-sized flours, fulfilling the objective of this current study. The damaged starch values for red lentil and yellow pea flour types increased with a decrease in flour particle size. Based on the Hausner’s ratios, the flowability of large-sized flour of red lentils could be described as passable; however, all the remaining five flour types were indicated as either poor or very poor. The findings of this study assist the millers to adapt yellow pea and red lentil milling technologies with minor modifications to the existing facilities. The study also helps in boosting the production of various baking products using pulse and wheat flour blends to enhance their nutritional quality.