Understanding Moringa oleifera analytics, extraction and cultivation for the production of high-quality proteins and bioactive natural products – A review

Moringa (Moringa oleifera) has received global attention recently resulting in a plethora of popular and scientific literature focusing mainly on its secondary compounds and their possible applications in food, feed and in pharmaceutical products. For example, high concentrations of polyphenols are found in moringa leaves with well-known radical scavenging potential. Likewise, unique glucosinolates that get converted into stable isothiocyanates, with high biological activity and much sought effects, including body weight loss can be found in the biomass. The use of moringa products is, however, limited, probably due to data heterogeneity concerning moringa agronomy, the composition of its relevant parts and processing techniques. For example, the crude protein content in dry moringa leaves varies between 15 % and 39 % in literature. Also, the viability of exploitation of pharmaceutically active compounds identified in moringa is not fully understood. This review provides a critical overview about the potentials and challenges in research related to the analysis, cultivation, extraction and application of moringa biomass and compounds derived from it. Specifically, the requirements for and bottlenecks of biomass analysis are highlighted first. Next, the effect of cultivation conditions on biomass and potential product yield is discussed. Further, the impact of extraction conditions and equipment selection for product recovery is discussed. Thereafter, the diversity of these products and potential applications are reviewed, with an emphasis on key compounds such as glucosinolates. Finally, the options for cascading biomass use to obtain multiple products in a production cycle are highlighted and several perspectives for future developments are outlined.