Preliminary screening of Hibiscus cannabinus L. (Kenaf) leaves for development of functional food

Hibiscus cannabinus L. (kenaf) is a beneficial plants originating from Africa and there are a lot of uses for kenaf reported in old folk. This study of research is done to screen secondary metabolite compounds and to develop new functional food from different varieties of kenaf leaves which involved the young leaves and the old leaves. Young and old leaves were approximately 2 months of age and 4 months of age, respectively. Young leaves look slightly different from the old leaves, particularly in colour and size. Young leaves are densely hairy at lower surface while old leaves are hairless. Young leaves also generally are pale green but old leaves generally dark green. Leaves were powdery dried using sunlight drying method and oven drying method. Thus the leaves were extracted using two different polarity solvents including 95% ethanol and hexane using Soxhlet method. The phytochemical analyses of leaves extracted were performed into qualitative tests and quantitative tests respectively. In the qualitative results, there were several bioactive compounds were identified definitely for instance, phenols, flavonoids, alkaloids, saponins and tannin. All the components stated were detected presence in both two samples of kenaf leaves. But saponin was detected slightly presence. While, in quantitative results, total phenolics content, total flavonoid content, total tannin content, estimation of vitamin C and 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) radical scavenging assay were conducted respectively. From the results obtained, the old kenaf leaves showed the most abundant bioactive compounds present rather than the young leaves. Hence, this research indicated that, kenaf leaves are highly potential as a one of the sources of functional food with their importance based on its antioxidant properties and the bioactive compounds properties present. Oolong tea was produced and as a prototype for this research. Furthermore, for future directions in the food industry, a few research will be performs in order to strengthens their properties.