Morphology, chemical composition and storage of grains of Moringa oleifera Lam

Abstract

Moringa oleifera has attracted interest as an agricultural crop due to its functional characteristics. However, the lack of comprehensive studies on the physical, chemical characteristics, processing and storage of grains is notable, which is crucial to improving processes and the production chain. Thus, with the aim of understanding the properties of Moringa grains and their interaction with post-harvest processes, this study aimed to carry out the physical and chemical characterization of the grains, as well as analyze the quality after storage, considering the variation in water content. Research was conducted at the Department of Agricultural Engineering at the Federal University of Lavras, using sources from the state of Maranhão with water contents of 13%, 10% and 7% (b.s). The grains were analyzed for their physical, ultrastructural and chemical characteristics. Even so, the mechanical extraction yield of the oil and its quality were evaluated for all samples, depending on the water content. The grains were stored in polyethylene silos for 8 months. The results demonstrated the absence of significant differences in the morphometric values and chemical characteristics of the oil, at different water contents. Grains with water contents of 0.10 and 0.13 b.s. showed greater water activity, which means that there was more water available to interact with other substances present in the grains. This led to greater difficulty in separating the wet phase and the lipid phase, resulting in lower oil removal efficiency during the mechanical exhaust process. Furthermore, after storage, a more significant manipulation of the oil was observed in grains with higher initial water contents, demonstrating lower oil stability in grains with high water contents.