Diversity of key cannabinoids, seed nutritional compounds and their quantification methods in the upcoming Southern African cannabis sector

Cannabis (Cannabis sativa L) is a versatile crop from which highly nutritious seed extracts and several pharmaceutical grade flower cannabinoids can be isolated and purified. These extracts have high demand worldwide as raw material in medicinal, nutritional and industrial sectors. Since commercial production of cannabis is a recent development in most Southern African countries, the cannabis seed industry in these countries is at its infancy and production relies mostly on germplasm imported mainly from Europe, China and North America. However, adapted but uncharacterized cannabis landraces that supply the local illegal drug markets are in widespread existence most Southern African countries including Zimbabwe. These already adapted landraces that have co-evolved in the different localities need to be characterized, so that they can either undergo improvement or be used directly as commercial crops. In this review, it was conceptualized that in the near future there is going to be need for full characterization of several cannabis landraces that have not been characterized before as scientists will be trying to bring them under formal utilization. This characterization will be achieved through exploring three major cannabinoids, namely Δ9 Tetrahydrocannabinol, Cannabidiol, Cannabigerol because they have the most profound human pharmaceutical properties. Nutritionally, emphasis will be directed to total fatty acids, proteins and amino acids composition. Gas chromatography and High-Performance Liquid Chromatography in combination with their different detectors are singled out as currently being the most popular platforms for the analysis of cannabis phytochemical. Nuclear Magnetic Resonance, Liquid Chromatography Tandem Mass Spectroscopy and Near Infra-Red Spectroscopy were also identified as the other top laboratory quantification methods and the strength and limitations of each method was discussed to enable users to select the most appropriate method that suits their unique circumstances. Overall, the most ideal quantification method depends on the expertise, resources and accuracy of the readings needed.