SOURCE:

Faculty: Physical Sciences
Department: Pure And Industrial Chemistry

CONTRIBUTORS:

Oguezi, V. U
Ajiwe, V.I. E
Eboatu, A. N

ABSTRACT:

In this study 43 commonly consumed foods in Eastern Nigeria are being analyzed to enable us know and compare the compositions of such foods with the existing standards. The foods were grouped into ten classes which include; fruits, vegetables, cereals, roots/tubers, oils, meat, fish, legumes/pulses, nuts and seeds. They were bought from various markets around Eastern States of Nigeria and were analyzed raw for nutritional, antinutritional, mineral compositions and calorific values calculated to ascertain the balance between nutrients and antinutrients which determine food quality. Results from proximate analysis showed that moisture content ranged between 0.39% in legumes and 45.33% in fruits; ash content, between 0.13% in oils and 25.00% in fruits; fat, between 1.27% in roots/tubers and 95.69% in oils; crude protein, between0.95% in roots/tubers and 64.30% in legumes/pulses, fibre content was between 0.00% in oil and 23.83% in fruits, and carbohydrates between 11.02% in fruits and 90.31% in roots/tubers. Proximate analysis results indicated that the foods were potential sources of nutrients needed for normal body function, if properly and adequately taken since they met the lower ranges of the Recommended Daily Intakes (RDI) and Acceptable Macronutrient Distribution Ranges (AMDR) and fairly met the upper ranges of both RDA and AMDR for nutrients. On the average, carbohydrate was found to be the major contributor to the calorific values of the foods followed by protein and fat: C(58:50%)> P(18.39%)> F(7.79%). Results from antinutritional analysis showed that saponins were the most abundant antinutrient in the foods, followed by alkaloids, oxalates, phytic acid and tannins:S(1.98g)>A(1.61g)>O(0.89g)>P(0.85) and >T(0.39g). The levels were all below reported toxic levels for all the antinutrients analysed. This indicated that the foods were good sources of phytonutrients and would be helpful in preventing some deadly diseases. The foods of the Easterners in Nigeria were also rich in essential minerals in the order: Ca (11.21mg)> Na (9.37mg)> K(6.38mg)> Mg(5.71mg)> Fe(5.13mg)> Zn(1.51mg)> Mn(0.82mg)> Cu(0.11mg)> P(0.03mg), on the average. This implied that the foods were rich sources of mineral, though none met the RDI of these minerals but if taken adequately and appropriately, could cure diseases associated with certain mineral deficiencies such as rickets, osteomalacia, hypokalemia and dehydration. The results equally showed that the foods contained toxic heavy metals in the order: Hg (0.73mg)> Ni (0.41mg)> Pb (0.30mg)> Cd(0.21mg)> Co(0.08mg) and As(0.06mg) on the average. This indicated that mercury which has no safe level was the most abundant toxic metal. Apart from Co and Ni (RDI 1mg and <1mg, respectively), other heavy metals analysed were not required in our diet and had no RDI value because they were simply toxic and pose health problem to humans. Results of physiochemical properties analysis of the common oils showed that the acid values were higher for red oil than groundnut oil but did not exceed 4.0mg/g expected for oils for edible purposes and thus were safe for human consumption. The peroxide values were higher for red oil but none exceeded 20-40mg/g oil that could lead to rancidity. The iodine values were low compared to 80-90mg/g expected for well refined oil hence the oils were saturated and should be consumed moderately.