Changes of nutrients in different green leafy vegetables during processing

Abstract

Green leafy vegetables are important protective foods and highly beneficial for the maintenance of health and prevention of diseases as they are good sources of micronutrients which can be utilized to build up and repair the body. In the present investigation, the changes in nutrient content of selected green leafy vegetables (such as tree lettuce (Pisonia alba), pasalai leaves (Basella alba), fenugreek leaves (Trigonella foenum), manathakkali leaves (Solanum nigrum) and moringa leaves (Moringa olifera)) subjected to different drying methods such as shade drying, cabinet drying and fluidized bed drying were studied. The results indicated that fluidized bed dried manathakkali leaves powder had highest β-carotene content (37,712µg/100g) followed by tree lettuce leaves powder (32,595µg/100g) pasalai leaves powder (29,800µg/100g), fenugreek leaves powder (26,628µg/100g) and moringa leaves powder (23,628µg/100g). The moisture content of GLV powders dried under different drying techniques ranged from 4.02 to 5.60 per cent. Also, tree lettuce leaves powder subjected to fluidized bed drying had significantly higher antioxidant activity (95.99%) compared to manathakkali leaves powder which had lowest (83.13%) antioxidant activity. The study revealed that the fluidized bed dried GLV powder samples subjected to pretreatment of blanching had higher nutrient content compared to respective GLV powder samples which were either dried under shade or cabinet dried. The results suggest that green leafy vegetables powder has high potential as micronutrient rich food contributing significant health benefits for women to combat micronutrient malnutrition.