Impact of Cooking Conditions of Sweet Potato Leaves (Ipomoea batatas) on the Hematological and Biochemical Parameters of the Rats (Wistar)

Leafy vegetables contain nutrients and micronutrients that are essential for the proper functioning of the body of living things. The latter can be affected when cooking leafy vegetables. The objective of this work was therefore to study the impact of varying cooking parameters of sweet potato leaves on body mass and hematological and biochemical parameters in the rats. To do this, the sweet potato leaves were cooked in 500 ml of water according to three cooking conditions by varying the leaf quantity and the cooking time: cooking n° 1 (300 g; 7.93 min), cooking n° 2 (400 g; 10 min) and cooking n° 3 (441.4 g; 15.07 min). Contents of protein, fiber, vitamin C, β-carotene, vitamin B9, polyphenol, flavonoid, iron and zinc of the precooked leaves were determined. The female rats were divided on the basis of their body weight into 4 groups of 5 rats each and were fed with pellets (reference food). The control batch received distilled water. Batches 1, 2 and 3 received, by force-feeding for 30 days, aqueous extracts of sweet potato leaves from cooking n° 1, cooking n° 2 and cooking n° 3, respectively. During the experiment, three blood samples were taken (day 0, day 15 and day 30) to assess the levels of white blood cells, red blood cells, hemoglobin, blood platelets and serum iron, and blood sugar. The results indicated that the aqueous extracts of precooked sweet potato leaves caused an increase in weight and, levels of hematological parameters and serum iron, and a decrease in blood sugar in rats. In addition, the cooking conditions of sweet potato leaves significantly influenced the weight and the levels of hemoglobin, blood platelet and serum iron in rats; while they did not significantly affect blood sugar and levels of white blood cell and red blood cell in rats. The cooking condition which gave the most satisfactory results was cooking n° 3 (441.4 g; 15.07 min). These results suggest that sweet potato leaves could be used in the treatment of anaemia, and hypertension, hence their importance in nutrition and health. However, it would be necessary to adopt a cooking condition that best preserves the virtues of sweet potato leaves.