ISSN 2375-0723
African Journal of Food Science Research Vol. 2 (1), pp. 037-043, January, 2014. © International Scholars Journals
Full Length Research Paper
Optimization of water-extract of phenolic and antioxidant compounds from Kinkéliba (Combretum micranthum) leaves
Beda Marcel Yapo1*, Veronique Besson2, Sylvain Beourou3 and Kouassi Koffi2
1Subunit of Pedagogy in Biochemistry and Microbiology, Unit of Training and Research in Agroforestry, University of Jean Lorougnon Guédé (UJLoG), BP 150 Daloa, Côte d’Ivoire.
2Food Research and Technology Division, Cargill West Africa, Abidjan, Côte d’Ivoire.
3Department of Parasitology-Mycology, Pasteur Institute, 01 BP 490 Abidjan 01, Côte d’Ivoire.
*Corresponding author: [email protected]. Tel.: +225 48 73 61 30/32 78 10 88; fax: +225 32 78 75 70
Accepted 22 November, 2013
Abstract
The hot water extract of dry kinkéliba leaves (DKL) is a traditionally widely delighted and consumed beverage in West Africa, especially during the fasting periods. It is believed to possess various health benefit effects such as diuretic, purgative, digestive, anti-viral and anti-malarial properties. However, the preparation of this beverage has not been optimized so far, which may underestimate its health benefit potential. In this study, the traditional preparation of the beverage, by decoction, was optimized in order to maximize the amounts of health benefit polyphenolic and other antioxidant compounds. The results showed that an optimal preparation with maximum solubilization of polyphenols required the brewing of approximately 20-25 g of DKL in boiling water for about 15-20 min. These conditions afforded an optimized extract (OEDKL) with a total phenolic content of 215.0 mg GAE/g and arabinogalactan-rich pectic polysaccharide content of 553.0 mg/g. Moreover, the OEDKL exhibited a high antioxidant capacity, as evaluated by DPPH [93.0% IP and EC50 = 15.0 (g/g)], ABTS (112.0 µmol TE/ g), or FRAP (376.0 µmol TE/g) assay, which was correlated with the total phenolic content (R2 = 0.897-0.991). Nevertheless, the pectic material detected within the beverage was likely to contribute to its interesting antioxidant properties. Therefore, it was suggested that the total antioxidant capacity of the OEDKL could result from synergistic interactions among the various antioxidant compounds present, including polyphenols and fractionated pectic materials.
Key words: Combretum micranthum, Beverages, Polyphenols, Pectic polysaccharides, Antioxidant properties.