VAIDYA, DEVINAARUN2021-11-112021-11-112021-11https://krishikosh.egranth.ac.in/handle/1/5810178002ABSTRACT Stinging nettle (Urtica dioica L.) family Urticaceae, is wild herbaceous, perennial, flowering plant having Stinging hairs and commonly found in moist or damp soil which is native to Europe, Asia, Northern Africa, America. It is known since ancient times as a wild source of food and herbal medicine but the plant remained under-utilized due to inherent trichomes present in the leaves and stems which are responsible for causing irritation to the skin. Drying of Stinging nettle leaves not only allow their use when the plants are physiologically inactive but also extend the consumption period and utilization at the time of food shortage especially for addressing micronutrient malnutrition. In this study, Stinging nettle leaves were harvested at two stages viz. Tender leaflets from the top with meristem and mature leaves. The initial physico-chemical analysis revealed higher quality of young leaves with respect to higher crude protein (4.36%), ascorbic acid (57.82 mg/100g), antioxidant activity (14.60%) and chlorophyll a (6.55 mg/l), chlorophyll b (2.07 mg/l), total chlorophyll (8.91 mg/100g). The effect of pre-treatment and drying of Stinging nettle leaves (viz. cabinet dried and vacuum dried) on chlorophyll a and b, ascorbic acid and total phenol content as well as antioxidant activity, were investigated. Blanching of Stinging nettle leaves include water blanching and steam blanching, but the central composite design using response surface methodology revealed that water blanching using 0.15% MgO along with 2% salt for 105 seconds had highest quality as evident from ascorbic acid (7.45 mg/100g), antioxidant activity (38.74%), total phenols (21.67 mg/100g GAE), total chlorophyll (11.96 mg/l) and chlorophyll a (6.86 mg/l) and b (3.08 mg/l). However, mechanical drying of nettle leaves resulted in a higher loss of chlorophyll a and b content compared to vacuum drying. In contrast, the total phenol content and total antioxidant activity was higher in vacuum dried Stinging nettle leaves compared to cabinet dried leaves. Stinging nettle leaves powder potentially be used as a cheap natural source of antioxidant and considered safe for human consumption because no microbial growth was recorded during their accelerated storage period at temperature 37 0C and 47 0C for different days interval. Hence, it is concluded that when Stinging nettle leaves processed by using appropriate method then it helps to retain the entire quality characteristics with excellent nutritional profEnglishThesis