Volarization of hibiscus calyxes by extraction of phenolic acids using solvent extraction method, and subsequent production of dietary supplements

Abstract

Locally, hibiscus juice is extracted from the roselle calyxes and is sold to the local community in small containers of about 350ml - 500ml at a cost range of about 1000/= to 1500/=, this usually yields low incomes for the local companies. Extraction and characterization of the hibiscus juice would enable further works of extraction of phenolic acids i.e. 3,4-dihydroxybenenzoic acid from the calyxes, and concentrate them into a dietary fibre or food supplement. This study involves the determination of optimum conditions for the extraction of hibiscus juice from the roselle calyxes. The study also covers the extraction of phenolic contents of hibiscus calyx using three different solvents of water, methanol and ethanol at different concentrations of solvent. This was done to examine the percentage yield of phenolic contents based on the concentration of the solvent used. The research further shows the analysis of the effect of changes in temperatures from 230c to 900c of solvent verses its effects on percentage yield of the phenolic 6acids due to thermal degradation of the phenolic contents. To archive the extraction, the calyxes where soaked in different solvents as mentioned above, and extraction was carried out at different concentrations of solvent accompanied with variation of the solvent temperatures to obtain samples that are suspected to contain phenolic acids. The extracted samples were then prepared for analysis in a High-Performance Liquid Chromatography machine that gave data that was used to compare the different extraction parameters of the research work. Results of the HPLC analysis showed that organic solvents at 100% concentrations i.e. Methanol and ethanol were better extraction solvents more than inorganic solvent of water for extracting phenolic compounds at an average temperature of 500c.