Physicochemical characteristics of kernel during fruit maturation of four coconut cultivars (Cocos nucifera L.)

Physicochemical characteristics of kernels from four cultivars of coconut were studied with the aim of increasing the value of coconut palm (Cocos nucifera L.), the main income of most equatorial coastal farmers. Studies were undertaken on West African Tall (WAT), Malaysian Yellow Dwarf (MYD), Equatorial Guinea Green Dwarf (EGD) and the improved PB121 hybrid, PB121+. Analyses were concerned with kernel weight, thickness, dry matter, oil, proteins and soluble sugars content at six stages (ranks) of nuts maturity. Chromatographic profiles of fatty acids of extracted oils were also determined. The results showed positive interaction between cultivar and maturity stage for all examined parameters. Then, PB121+ nuts, without kernel at the beginning of maturation, had the greatest weight (358.7 g) at rank 26. Kernel thickness was maximum (13.28 mm) in WAT at rank 26 due to nuts complete maturity. Oil content increased until the highest value of 73.01% in WAT at rank 23 before decreasing. Total soluble sugars, essentially non-reducing sugars, were maximum (9.09 g/100 g) in MYD fruits at rank 26. The fatty acids profiles showed an increasing proportion of lauric acid during nuts maturation. These results indicated the possibility of specific utilisations of coconut kernels according to cultivar and maturity stage.