Updating the Data Base of Indigenous Raw Food Materials by Analyzing Their Chemical Compositions

Abstract

Introduction: The porosity of recent data on the chemical compositions of indigenous food might contribute to poor food choices thereby promoting food and nutrition insecurity. This study provides data on the proximate, mineral and antinutrient compositions of raw, Triticum aestivum, Musa paradisiaca, Xanthosoma sagittifolium, Ipomea batata, Zea mays and Sphenostylis stenocarpa. Methodology: The raw food materials were purchased in Nigerian markets. Corn grains and African yam bean (AYB) seeds were sorted to remove impurities and separately milled into fine flours. Green matured plantain fruits, cocoyam, yellow and orange fleshed sweet potatoes tubers were separately washed to remove adhering soil particles, peeled and sliced into a thin thickness of about 2 cm and then dried in a food dehydrator (40- 50°C) for 24 hr. After drying, they were separately milled into fine flours. Chemical properties were analyzed using standard laboratory methods. Data generated were computed using means and standard deviations. Results: The ranges of the proximate compositions of the food materials were as follows: Moisture 4.3-11.8%, ash 0.6 -2.8%, dietary fibre 3.2-17.5%, fat 0.8-4.3%, protein 2.8 - 20% and available carbohydrate 48.5 -72.5%. The mineral contents of the samples were in the following ranges; iron 0.8-5.4 mg/100 g, zinc 0.51-2.43 mg/100 g, calcium 8-109 mg/100 g, potassium 135-325 mg/100 g, sodium 3-12 mg/100 g, phosphorus 84- 688 mg/100 g, magnesium trace -119 mg/100 g. The antinutrients were as follows: trypsin inhibitors 1.85 IU/mg, phytate ranged from 5.1-6.57 mg/g, oxalate 0.21-0.29 mg/g, saponins 0.03-0.02 mg/100 g, raffinose 0.88- 2.18%, stachyose 1.93 – 3.16%, lectins 32.5 Hu/100 g and tannins 0.9 mg/g. Conclusion: Knowing the nutrient contents of raw food materials will help food producers/processors and consumers combine foods leveraging on the comparative advantage of each nutrient to make up for limited nutrient(s). Also, knowledge of the antinutrient compositions of raw food staples will aid decisions on adequate processing methods to be employed in reducing or eliminating them.