Comparative study of nutritive and antinutritive values of Dioscorea rotundata and Solanum tuberosum cultivated in Lafia, Nigeria

Abstract

Yams (Dioscorea rotundata) and Irish potatoes (Solanum tuberosum) are important staple tubers rich in carbohydrates, vitamins, and minerals. However, they also contain anti-nutritive compounds that can affect nutrient bioavailability and health. Understanding their properties is essential for optimizing dietary use and processing to enhance health benefits. This study aims to evaluate and compare the nutritive and antinutritive values of D. rotundata and S. tuberosum. D. rotundata and S. tuberosum were peeled, oven-dried, and analyzed using methods from the Association of Official Analytical Chemists. The values obtained for each proximate in each raw sample are D. rotundata: 11.76% crude protein, 2.99% fat, 6.29% ash, 9.99% crude fibre, 5.30% moisture, and 63.60% carbohydrate. S. tuberosum: 14.27% crude protein, 3.22% fat, 5.31% ash, 8.53% crude fibre, 5.52% moisture, and 63.74% carbohydrate. The phytochemicals are as follows: D. rotundata: 6.52% oxalate, 0.33% saponins, 7.37% alkaloids, 9.13% flavonoids, 2.14 mg/100 g tannins, 0.42 mg/100 g cyanide, 333.63 mg/100 g phytate, and 0.56% total phenol. S. tuberosum: 2.73% oxalate, 0.31% saponins, 9.47% alkaloids, 3.25% flavonoids, 3.04 mg/100 g tannins, 1.52 mg/100 g cyanide, 300.10 mg/100 g phytate, and 0.79% total phenol. S. tuberosum was found to be richer in protein and amino acids, whereas D. rotundata was found to have higher levels of crude fiber and ash. Both tubers have antinutritive factors, necessitating effective processing techniques to enhance their nutritional value and reduce health risks.