Preservation of the Moringa oleifera Constituents by Freeze-drying

Abstract

Aims: Moringa oleifera is an edible plant. A wide variety of nutritional and medicinal virtues have been attributed to its roots, barks, leaves, flowers, fruits and seeds. The objective of this research was to evaluate the preservation of the constituents of the powder obtained from the moringa seeds by freeze-drying comparing it with the in natura (natural extract). Place and Duration of Study: The work was conducted at the Laboratory of Processing and Storage of Agricultural Products, Department of Agricultural Engineering, Federal University of Campina Grande, Brazil, in the period from August to November 2018. Methodology: The seeds were peeled and macerated manually. Freeze-drying was done in a Liotop® L101 benchtop freeze drier. After dehydration the samples were disintegrated and the physical and physico-chemical constituents were evaluated before and after freeze-drying in terms of apparent density, real density, porosity, compacted density, compressibility index, Hausner factor, solubility, moisture content and activity, ash, titratable total acidity, pH, protein, lipids and carbohydrates. Results: The in natura powder presented better results for the physical analyzes of the densities: apparent, real and compacted, however, it was observed that for the other physical parameters and physicochemical constituents the freeze-drying promoted the preservation of these in front of the in natura. Freeze-drying caused a significant reduction in moisture content, pH and lipid activity, making the powders more stable and contributing to the maintenance of their physico-chemical qualities. The inverse was observed for the ash, protein and carbohydrate contents, where freeze-drying promoted increases in their contents. Conclusion: Freeze-drying presents as an appropriate method in the preservation of moringa constituents, with emphasis on physicochemical.