Filtration Approach of an Optimized Extract of Garcinia kola Heckel by Membrane Separative Techniques

Abstract

Aims: The aims of this study was to determine the optimal conditions for extracting active molecules from Garcinia kola seeds and to clarify the extract obtained by membrane microfiltration. Study Design: Garcinia kola seeds were collected in October 2024-February 2025 from the region of Agneby-Tiassa, Côte d’Ivoire. Harvested seeds were transferred to the laboratory until used in the experiments. Place and Duration of Study: This study was carried out during season 2024-2025 in the Laboratory of industrial process engineering at INPHB, Yamoussoukro. Methodology: After drying and powder processing, the effect of four parameters (solvent type, solid-liquid ratio, extraction mode and extraction time) on polyphenol extraction from kola seeds were studied and a full factorial design (2k, k=4) was used to optimize the extraction conditions. Kola extract obtained under these conditions were clarified by Microfiltration and fractions coming from the membrane processes were analyzed for their content in active compounds. Results: Results showed that G. kola extract contains substantial proportion of active compounds such as polyphenols (flavonoids in particular). To have a maximum content of polyphenols and total flavonoids, the extraction must involve the infusion of 1 g of material in 100 mL (w/v) of Ethanol (50%) for a period of between 3 and 24 hours. In the predicted optimal conditions, experimental values were 337.18 mg/L GAE and 671.05 mg/L QE for total polyphenols and total flavonoids, respectively. Experimental data were very close to the predicted values. The application of microfiltration on optimized kola extract resulted in a clarified juice with bioactive compounds. The material balance indicates a high proportion of compounds in the filtration permeate, which reflects satisfaction with the process applied. Conclusion: The application of tangential filtration to kola extract could constitute an industrial recovery approach for the latter. Kola seeds can be considered as a natural source of phenolics compounds with good antioxidant capacity.