Effect of Processing Methods on Nutrient Andantinutrient Composition of Justicia Secunda Leaves

Abstract

Justicia secunda as a medicinal plant belongs to the family of Acanthaceae ,the leaf is an under-utilized medicinal vegetable that is believed and utilized as blood tonic by the local people and especially among the sect of some religious people that refuse blood infusion in medical conditions. This study examined the effect of processing methods on the nutrient and phytochemical composition of justicia secunda leaves. The leaves were subjected to blanching pre-treatment before sun drying for 72 hrs oven drying at 55 0C for 48 hrs and air drying for 120 hrsThe proximate, vitamins, minerals and phytochemical analysis were conducted on the samples using standard procedures. The results varied significantly (p<0.05) in all the parameters measured according to the different processing treatments. Proximate composition of the samples ranged for crude protein (18.20-21.73%), crude fat (7.80-9.10%), crude fibre (12.00-14.90%), ash (15.50-17.40%), moisture (8.00-9.00%) and carbohydrate (27.98-35.50%). Mineral composition ranged for calcium (18.20-34.10 mg/100g), magnesium (47.11-54.29 mg/100g), sodium (126.43-136.47 mg/100g), potassium (425.49-453.03 mg/100g), phosphorus (135.40-145.76 mg/100g) and iron (33.07-38.94 mg/100g). Vitamin composition showed that thiamine (B1) ranged from 0.04-0.31 mg/100g, riboflavin (B2) (0.21-1.7 8mg/100g), niacin (B3) (0.49-1.89 mg/100g), vitamin C (6.31-19.48 mg/100g), while vitamin E ranged from (1.97-6.78 mg/100g). Anti-nutrient contents ranged for tannin (4.82-16.89 mg/100g), phenol (7.41-19.23 mg/100g), alkaloids (2.05-7.07 mg/100g) flavonoids (4.90-9.85 mg/100g) and saponin (3.25-8.35 mg/100g. Overall, the results revealed that air drying methods retained greater concentrations of fibre, minerals, vitamins and anti-nutrients than other processing methods. The high micro-nutrient contents of iron, anti-nutrient compounds and B group of vitamins in this processed vegetable reveals why it is used intuitively by the traditional people to boost health conditions due to the functional roles of iron, phytonutrients and B group of vitamins in heamopoisis in preventing morbidity and mortality especially among children.