Indian Journal of Science and Technology

Abstract

Citrullus colocynthis (melon) and Afzelia africana (akparata) are used in soup preparation as soup condiment and soup thickener respectively. The chemical compositions of these food materials were investigated to know the extent to which they contain natural substances (anti-nutrients) which may affect the metabolic and physiological response of man and animals when consumed. The anti-nutritional factors in the materials were investigated as well as the extent of toxicity on the liver when consumed even in excess, using Wister albino rats fed with varied ratios of growers mash and seed flour. The level of cyanogenic glycosides, oxalates, trypsin inhibitors were very low in all the samples and the values in both Afzelia africana and Citrullus colocynthis were 0.33±0.01 and 1.58±0.24 mg/100g of the samples respectively. The concentrations of other anti-nutrients in Afzelia africana were oxalates 1.08±0.02, trypsin inhibitors 2.35±0.07 and hemagluttinin 4.49±0.32 mg/100g while the values in Citrullus colocynthis were 1.30±0.32, 0.75±0.02 and 5.63±0.43 mg/100g respectively. The level of phytate was relatively higher. The concentration of tannins and alkaloids were found to be significantly high (p<0.05) in both samples when compared with other anti-nutrients. The values were relatively lower in the popular Citrullus colocynthis than in the unpopular Afzelia africana. The concentration of tannins in Afzelia africana and Citrullus colocynthis were 62.22±4.22 and 49.67±3.91mg/100g while alkaloids were 59.62±4.22 and 43.63±3.18 mg/100g respectively. The investigation into the activities of the liver enzymes revealed that there was no significant difference (p>0.05) in the activity of alanine transferase in all the groups when compared with the control. However, there was a significant increase (p<0.05) in group B which might be considered to be dose-dependent. The activity of Aspartate Transferase (AST) increased in both groups but the increase was not significant (p>0.05) when compared with the control. AST activity decreased significantly in group A (p>0.05), while alkaline phosphatase generally decreased in all the groups. There were similarities in the effects of the condiment and the thickener which were comparable. The results showed there was no significant difference in the anti-nutritional constituents and in their effects on the liver. Generally, cooking and other forms of processing such as fermentation have the ability of lowering the anti-nutritional components of food materials.
Keywords: Citrullus colocynthis, Afzelia africana, Soup, Thickener, Anti-nutrients, Enzymes