Abstract

Breeding for nutritional quality of food/feed crops had somewhat been neglected by plant breeders all through the years. The objectives had mainly been focused on disease resistance and yield. Current concerns about the global food security need to encompass the issue of breeding for nutritional quality of food plants. One of the issues that revolve around the nutritional quality is the presence of antinutrients. These substances reduce the bioavailability of nutrients such as proteins, vitamins and minerals which could result in malnutrition especially in developing countries. Designing breeding programmes for the enhancement of nutritional quality of food crops require information on the types and concentrations of these antinutrients in such crops. This study was thus initiated to obtain information on the concentrations of the antinutrients - cyanogenic glycosides, oxalates, phytic acids, tannins and alkaloids - of Annona muricata (a fruit), Corchorus olitorius (a vegetable/grain crop) and Pentaclethra macrophylla (a legume) which are common among the local people of South East of Nigeria. Results showed that mean contents of oxalate, phytic acid, tannins and alkaloids were within permissible limits while high contents of cyanogenic glycosides were observed in C. olitorius (0.551 ± 0.0165 mg/100 g) and P. macrophylla. Fermentation did not reduce the level in P. macrophylla. The values obtained in unfermented and fermented seeds were 0.577 ± 0.0004 mg/100 g and 0.575 ± 0.003 mg/100 g respectively. The results were discussed bearing in mind the need for plant breeders and nutritionists to design programmes that will balance the adverse and beneficial effects of these antinutrients since many of them have also been found to be pharmacologically beneficial.

Key words: Antinutritional, contents, breeding, quality.