Comparative Study on the Physicochemical Properties of Two Varieties of Cassava Peels (Manihot utilissima Pohl)

摘要

Some physical and chemical properties of the peels of six cassava cultivars of both sweet and bitter varieties obtained from Nigerian Root Crop Research Institute (NRCRI) have been determined. The results of the proximate analysis showed that the fresh samples contained average moisture content of 71.43% and 72.07%, dry matter 28.47% and 27.93%, crude protein 1.40 and 1.98%, fat 0.36 and 0.33%, crude fibre 6.52 and 4.89%, ash 2.79 and 1.87% , and carbohydrate 17.40 and 18.86%. The dried peels showed moisture content of 59.05 and 64.95%, fat 1.21 and 1.31%, fibre 16.12 and 10.78%, ash 5.89 and 4.86%, and carbohydrate 12.62 and 12.61% for bitter and sweet varieties, respectively. The mineral and vitamins found in the fresh peel were Ca: 14.69 and 9.35 mg/100 g, Mg: 12.80 and 9.33 mg/100 g, K: 98.67 and 81.33 mg/100 g, Na: 12.87 and 9.33 mg/100 g, P: 29.0 and 46.67 mg/100 g, vitamin A: 1.59 and 1.02 mg/100 g, vitamin C: 30.43 and 34.83 mg/100 g, while the dried peels contained Ca: 52.10 and 37.41 mg/100 g, Mg: 30.40 and 24 mg/100 g, K: 264 and 206.67 mg/100 g, Na: 14.47 and 12.60 mg/100 g, P: 140.33 and 271.50 mg/100 g, vitamin A: 8.15 and 6.72 mg/100 g and vitamin C: 50.97 and 45.10 mg/100 g for bitter and sweet varieties, respectively. The anti-nutrients found were HCN: 19.99 and 12.78 mg/kg for bitter and sweet varieties of the fresh peels, tannin: 0.19% in both samples. In the dried samples, HCN content was 253.33 and 252.00 mg/kg, tannin 0.19 and 0.12% for bitter and sweet varies, respectively. These results show that cassava peel contained some nutrients and a number of anti-nutrients hence cassava peal which are presently environmental waste can be modified and use as an animal feed.