Influence of Maturity Stage and Cultivar on the Proximate, Mineral and Amino-Acid Composition of <i>Cocos nucifera</i> L. Kernel from Côte d’Ivoire Coconut Germplasm

Abstract

Cocos nucifera L. is the most important coastal crop in Côte d'Ivoire and its production is the main source of income for farmers. Some 53 coconut cultivars have been developed by the Marc Delorme Coconut Research Station of the Centre National de Recherche Agronomique to provide producers with high-yielding, disease-resistant planting material. However, few data on the biochemical variability of the kernels of these coconut cultivars is known. Therefore, the nutritive characterization of coconut kernels is necessary for the selection of nutrient-rich cultivars for coconut breeding programs and for coconut food valorization. The present study was carried out to evaluate the nutritive composition of four coconut kernel cultivars selected at different maturity stages at the Marc Delorme Coconut Research Station of the National Centre for Agricultural Research. The ANOVA results show a significant effect (p<0.05) of coconut cultivar and maturity stage on kernel nutritive parameters. Moisture, carbohydrate and soluble sugars contents were maximal at 10 months and decreased significantly (p<0.0001) during kernel maturation. Protein, fat, fibre, ash, minerals and amino acids increased significantly (p<0.05) and were maximal at 12 months. The improved West African Tall (WAT⁺) coconut kernel contains minimum moisture (5.07%), maximum fibre (11.29%), fat (55.42%) and energy (607,41 kcal/100g), while the improved Rennell Island Tall (RIT⁺) contains maximum carbohydrates (32.13%), reducing sugars (2.78%) and protein (8.63%). The improved hybrid PB113⁺ also contains maximum ash (1.56%), total sugars (7.24%) and non-reducing sugars (4.98%). Potassium (62488.50 – 74104.34 ppm) and histidine (654.66 – 1287.44 mg/100g) were the predominant minerals and amino acids in coconut kernel. The hybrid cultivars (PB113⁺ and PB121⁺) generally had higher mineral and amino acid contents than the tall cultivars (WAT⁺ and RIT⁺). These results suggest that there are differences in the nutritional composition of Cocos nucifera kernels between cultivars depending on the stage of maturity. The data obtained will provide useful information for the selection of coconut cultivars and their use in food products.