Comprehensive evaluation of nutritional and phytochemical qualities of turmeric (<i>Curcuma longa</i> linn) leaves

Abstract

Turmeric (Curcuma longa L.), is a member of the family zingiberaceae, which grow in tropical climate. The matured leaves used in this study were source from Obio Akpa, Oruk Anam Local Government Area of Akwa Ibom State, Nigeria. Sample of the leaves were analyzed in the laboratory for proximate, gross energy, minerals, vitamins, and photochemical compositions. Values obtained for the proximate analysis of C. longa leaf were; dry matter (88.13 ± 3.26%), crude protein (25.22 ± 1.67%), ether extract (4.03 ± 0.35%), crude fibre (16.73 ± 1.00%), ash (9.65 ± 0.62%), and nitrogen free extract (32.49 ± 1.40%) respectively. The gross energy value was 4110.00 ± 0.10 kcal/kg. Mineral and vitamin composition analysis of the leaves of C. longa gave the following values; calcium (0.26 ± 0.04%), phosphorus (0.38 ± 0.10%), potassium (0.89 ± 0.10%), magnesium (0.28 ± 0.00%), sodium (0.19 ± 0.10%), iodine (7.30 ± 0.54 mg/kg), zinc (48.74 ± 1.21 mg/kg), cobalt (0.41 ± 0.11 mg/kg), manganese (36.17 ± 1.04 mg/kg), vitamin E (31.38 ± 1.00
mg/100g), vitamin A (254.80 ± 2.80 mg/100g), vitamin B6 (1.27 ± 0.20 mg/100g) and vitamin B12 (0.07 ± 0.01 mg/100) respectively. Phytochemical compositions were, curcumin (0.006 ± 0.01%), demethoxycurcumin (0.004 ± 0.00%), bisdemethoxycurcumin (0.003 ± 0.00%), tannin (0.04 ± 0.01%), saponin (0.22 ± 0.02%), alkaloids (0.32 ± 0.10%) and flavonoid (0.01 ± 0.00%) respectively. The results of the current study indicated that turmeric leaf meal will be a good ingredient for livestock feed production.