Processing of Moringa leaves as natural source of nutrients by optimization of drying and grinding mechanism

Abstract

AbstractIn this study, Moringa leaves were processed in two steps (1) drying and (2) grinding. In the first step, leaves were dried with different drying treatments including conventional, laboratory and advanced methods to optimize drying conditions in terms of maximum nutrients preservation and color quality. During the second step, leaves were ground with three different grinding mills including hammer, dry, and cutter mills to study the effect of grinding mechanism in combination with particles size and moisture content on the flowability of the powder. The flowability was measured using conventional and advanced methods including Carr Index and Cohesion Index. Oven drying at 50 °C was found to be the optimum conditions in terms of maximum nutrients and color preservation of Moringa leaves. The grinding mechanism having a substantial impact on the flowability of the powder produced in different types of mills. The effect of moisture content and particle size on Moringa leaves powder was also investigated and found that moisture content directly affects the flowability of Moringa leaves powder followed by particles size and shape. We have also noted powder sample prepared by the impact mechanism (hammer mill) with particle size 50 µm and moisture content 5% having appreciable flowability as compared to the samples processed by cutting (dry mill) and shattering (cutter mill) mechanisms. This study conveys an ultimate understanding regarding processing (drying and grinding) of Moringa leaves powder.Practical ApplicationsDried Moringa is restricted to use as dietary purposes because of its unpleasant taste, which becomes further bitter after drying procedure. Therefore, powder of Moringa leaves can be processed into different forms such as tablet, capsules and cereal formulations. For this purpose, a comprehensive study has been carried out to increase the understanding of drying and flow characteristics of Moringa (leaves and powder) using different drying and grinding mechanisms. The findings of this study regarding drying treatments, nutrients preservation, flowability and different grinding mechanisms can also be applied to other herbs and leaves. A correlation between Carr Index and Cohesion Index established successfully. This study will be helpful to conduct further research in food processing because Carr Index is simple and easy to measure as compared to Cohesion Index that requires both texture and powder flow analyzers.