Dried ponnaganni leaves (Alternanthera sessilis): A nutritious product with the potential for value addition

Abstract

Green leafy vegetables are an excellent source of nutrients like vitamins, minerals and dietaryfibre and widely included in a habitual diet of the rural populace. Due to their perishable nature andseasonal availability, fresh green leafy vegetables are processed quickly and cooked before it served forhuman consumption. Considerable efforts have taken to increase the shelf life of green leafy vegetablesby conventional drying methods and presumed as a low-cost/convenient technology in many parts of theworld. Hence, this study aimed to preserve Ponnaganni (Alternanthera sessilis), underutilized greenleafy vegetables,through cabinet drying and determine the impact of cooking the leaves before drying onits nutritional, functional and phytochemical quality. Collected Ponnagannileaf bundle from the localvegetable market were cleaned, washed, separated the leaves then cooked by boiling for 20 min,simmering for 10 min and steaming for 10 min. The cooked and uncooked leaves were dried at 60ºC for4-5 hours in a cabinetdrier, made into powder and stored in the air-tight containers under refrigerationtemperature. The quality of dried leaves was assessed by analyzing their nutrient content, functionalproperties and phytochemical profile as per the standard methods. Results of the nutrient analysisrevealed that dried Ponnaganni leaves were high in protein (24.25g%), minerals (18.94g%) and crudefibre (8.13g%) and low in moisture (6.69%). Also the dried leaves exhibited high water absorptioncapacity (3.82 g/g), oil absorption capacity (1.66 g/g) and emulsifying activity (41.05%). Phytochemicalscreening reports that aqueous extract of dried Ponnaganni leaves were loaded with manyphytochemicals except anthocyanin. The cooked leaves showed a noticeable change in the nutrientscontent, functional properties and phytochemical profile compared to uncooked leaves. The findingssuggest that dried Ponnaganni is a nutritious product and it can be used in food formulations thatnecessitate high protein, minerals and fibre.