ABSTRACT

The effects of different processing treatments on the chemical compositions of purple joy leaves (Alternanthera brasiliana) was studied. The vegetable was subjected to different processing methods including boiling, shade drying, sun drying and the unprocessed one served as the control. Vitamin, mineral and phytochemical contents ofthese samples were determined. The results show that vitamin C contents ranged from 220.23 - 239.47 mg/kg, thiamine (Bl) contents ranged from 8.10 - 13.54 mg/kg, riboflavin (B2) contents ranged from 601.77 - 659.40 mg/kg, and beta carotene contents ranged from 1779.93 - 1927.85 pg/g. Boiling had the lowest value for vitamin C, thiamine, riboflavin, and beta carotene while control had the highest value for vitamin C, thiamine, riboflavin, and beta carotene. The values for vitamin C, thiamine, riboflavin, and beta carotene decreased with different processing methods adopted. Calcium contents ranged from 15.677 - 18.133 mg/g, zinc contents ranged from 0.287 - 0.343 mg/g, magnesium contents ranged from 8.653 - 9.193 mg/g, sodium contents ranged from 0.810 -1.217 mg/g, potassium contents ranged from 21.03 - 21.23 mg/g. Boiling method had the least values for only calcium, zinc, magnesium and sodium while shade and sun drying method had the least value for potassium. Control had the highest values for calcium, Zinc, Magnesium, Sodium and Potassium. The values for Calcium, Zinc, Magnesium, Sodium and Potassium decreased with different processing methods adopted. Alkaloid contents ranged from 507.92 - 513.92.mg/kg, flavonoid contents ranged from 459.92 - 471.20 mg/kg, anthocyanin contents ranged from 1543.25 - 1571.22 mg/kg, phenol contents ranged from 14689.97 - 14801.41 mg/kg, tannin contents ranged from 139.83 - 143.57 mg/kg, saponin contents ranged from 151.02 - 168.75 mg/kg. Boiling had the least values for all the parameters determined in the phytochemical while control had the highest values. The values decreased with different processing methods adopted. This study has shown that the different processing methods adopted had a significant effect on the nutrient quality ofA. brasiliana leaf.