Effect of Processing Treatments on the Micronutrients and Phytochemicals in Lasianthera africana Leaf

¹Inyang, U. E. and ²Ani, J. C.

¹Department of Food Science and Technology, University of Uyo, Akwa Ibom State, Nigeria

² Department of Food Science and Technology University of Nigeria, Nsukka, Enugu State, Nigeria

E-mail: inyang.ufot@yahoo.com

ABSTRACT

White variety of Lasianthera africana leaves were cut (2mm width), shared into four equal portions of 1kg each and subjected to three different treatments while one portion (raw leaf) served as the control. The treatments were oven drying (50^oC), blanching in hot water at 100^oC for 3 minutes and dried (50^oC) and blanching in unripe plantain peel ash solution (0.50%) at 100^oC for 3 minutes and dried (50^oC). The effects of these treatments on the minerals, vitamins and phytochemicals were investigated. The raw leaves contained  calcium (190.25±0.44mg/100g), sodium (75.69±0.95mg/100g), potassium (78.98±0.78/100g), magnesium (14.68±0.74/100g), zinc (5.95±0.52mg/100g), iron (3.96±0.55mg/100g), phosphorus (17.79±0.81mg/100g), ascorbic acid (109.64±0.0.08mg/100g), beta-carotene (2.86±0.04mg/100g), riboflavin(0.22±0.03mg/100g), thiamine(1.01±0.06mg/100g) alkaloid (2.67±0.33g/100g), flavonoids (0.32±0.03g/100g), saponin (3.09±0.04g/100g), tannins (0.28±0.03g/100g), HCN (2.16±0.08mg/100g), phytate (33.46±0.08mg/100g), oxalate (9.54±0.06mg/100g) and trypsin inhibitor (1.73±0.04 TUI/mg). The unblanched and blanched dried samples had lower values of the above constituents than the raw leaf. Unblanched dried leaves retained higher minerals, vitamins and phytochemicals than the blanched dried samples. Unripe plantain peel ash solution blanched and dried leaves retained higher minerals but lower vitamins and phytochemicals than hot water blanched and dried samples.