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The effect of short-term storage on the protein, phosphorus and phenolic content as well as peroxidase and o-diphenolase activities of cut, harvested Jamaican yam (Dioscorea sp) tubers (D rotundata. D alata and D cayenensis) was studied. There was an initial increase in the total phenolic content up to the third week of storage followed by a gradual decrease to the sixth week. Phenolic content was found to be highest in D cayenensis followed by D rotundata and D alata. The activities of peroxidase (EC 1. 11. 1. 7) and o-diphenolase (EC 1. 10.3.1) increased steadily up to the third week of storage and thereafter decreased to the fifth week. The intensity and rapidity of browning in tubers when cut, correlated very closely with the tuber o-diphenolase and phenolic content levels while the onset of rotting correlated with the peroxidase activity levels in the species studied.

Techniques for maximising the extraction of nitrogen from the West African locustbean seed (Parkia filicoidea Welw.) have been investigated. Maximum extraction (93 %) of nitrogen was obtained using a meal:solvent ratio of 2% with 0.05M NaOH. However, from the economic viewpoint a meal:solvent ratio of 1% using 0.01M NaOH would be cheaper. This ratio extracted 82% of the seed nitrogen. Other solvents such as sodium chloride solution and calcium hydroxide were not as efficient.