Total Polyphenols, Total Flavonoids, Condensed Tannins, and Antioxidant Activity of Borassus aethiopum (Arecaceae) ripe fruits’ Peels, and Peel-Pulps, Dried at Different Temperatures
Kan Adonise Yao *
Department of Agriculture and Animal Science, Graduate School of Agriculture, Institut National Polytechnique Félix Houphouët Boigny, P.O. Box 1313, Yamoussoukro, Côte d'Ivoire.
Tagouèlbè Tiho
Department of Agriculture and Animal Science, Graduate School of Agriculture, Institut National Polytechnique Félix Houphouët Boigny, P.O. Box 1313, Yamoussoukro, Côte d'Ivoire.
Nahoulé Silué
Agropastoral Management Institute (IGA), Laboratory of Animal Production and Health, Université Péléforo Gon Coulibaly de Korhogo, P.O. Box 1223, Korhogo, Côte d'Ivoire.
Nogbou Emmanuel Assidjo
Department of Food Science, Graduate School of Agriculture, Institut National Polytechnique Félix Houphouët Boigny, P.O. Box 1313, Yamoussoukro, Côte d'Ivoire.
Kisselmina Youssouf Koné
Department of Food Science, Graduate School of Agriculture, Institut National Polytechnique Félix Houphouët Boigny, P.O. Box 1313, Yamoussoukro, Côte d'Ivoire.
*Author to whom correspondence should be addressed.
Abstract
Aims: To measure their possible beneficial contributions on the rabbits’ health, Borassus aethiopum ripe fruits’ peels and combined peel-pulp were dried at 60, 65, 70 and 75oC.
Place and Duration of Study: On January and February 2023, Borassus aethiopum ripe fruits were collected within the graduate school of agronomy at the National Polytechnic Institute Felix Houphouët Boigny in Yamoussoukro, Côte d’Ivoire.
Methodology: The unspoiled fruits were peeled. One sample was composed of peels without the pulps, and a second was composed of peel and pulp combined. Following, they were dried during 5 days in ovens. Then, the products were crushed, and sieved. Thereafter, the products were extracted with distilled water through maceration and decoction for 1 hour. Afterwards, total phenols (TP), total flavonoids (TF), condensed tannins (TC) contents, and antioxidant activity (AOA) were assessed.
Results: The best extracts were obtained through decoction. Moreover, the peels presented the highest TP extract for 0.082+/-0.001 mg GAE/g at 70oC. Whereas the lowest TP extract was observed in the combined peel-pulp dried at 70oC for 0.067+/-0.001 mg GAE/g. However, concerning the TF, the peel-pulp dried at 75oC gave the best extracts through maceration, for 0.0450+/-0.007 mg QE/g. Globally, results revealed that the peels contain higher flavonoid contents than the combined peel-pulp. Regarding AOA, the extracts had much higher free radical scavenging capacity in the peels than in the combined peel-pulp parts. The highest antioxidant activity was observed with the peels dried at 70oC for 6.653+/-0.075 μmol TE/g, while the lowest value was observed with the combined peel-pulp dried at 70oC for 1.996+/-0.075 μmol TE/g. With condensed tannins, the best output was obtained with the peel dried at 60oC for 0.468+/-0.003 µg CatE/g.
Conclusion: Borassus aethiopum ripe fruits’ parts can be dried between 65 and 70oC. So, they could be good sources of fibres and phytochemicals for rabbits’ diets.
Keywords: Antioxidant activity, Borassus aethiopum, condensed tannins, rabbits, total polyphenols