ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 95 Number 2
Physico-chemical characteristics of Kola nuts [Cola nitida, Vent. (Schott & Endl.)] as influenced by curing period
Fresh nuts of Cola nitida [Vent, (Schott & Endl.)] are normally treated to some periods of curing after harvesting and extraction from pods. Non-definition of the appropriate period of curing has erroneously extended the period of curing into the period of storage. This undoubtedly affects the physico-chemical traits of the nuts. To establish an appropriate curing period for kola nut, an experiment was set up to investigate variations in physico-chemical parameters of the nuts as influenced by curing-period. Kola nuts were extracted from freshly harvested ripe pods, and nuts (>15 g each) were selected for the study. At the commencement of the curing process and at two-weekly intervals for the 12-week duration of the curing, 30 nuts were selected for assessment, giving a total of seven treatments. Fresh weight of each sample was measured and the dry weight determined after oven-drying at 800C until constant weight. The samples were pulverized and the following physico-chemical parameters were determined in g/g of the dried and milled sample: Non-Protein Nitrogen (NPN), Pectin, Caffeine, Tannin, Polyphenol, Sugar, Crude Protein (CP), Crude Fibre (CF), Ether Extract (EE), Ash Content (AC), Moisture and Dry Matter Content (DMC). The results showed that NPN, Pectin, Caffeine, Tannin, Polyphenol and Sugar contents of kola nuts increased with curing period. However, CP was lowest in 12-week cured nuts (WCN) (7.00g/g) and 2-, 4-, 10- WCN as well as fresh nuts (7.35g/g) and highest in 6-WCN (8.25g/g). Percentage CF was highest in fresh nuts and lowest in 12WCN. In conclusion, curing improved food quality characteristics of the kola nuts in this study; 6 weeks curing period is adequate for optimum quality.
Keywords: Cola nitida, curing period, proximate content, sugar, caffeine