Nutritional Profiling and Antioxidant Capacity of Diplazium esculentum (Retz.) Sw., an Underutilized Wild Fern from Seraj Valley, Himachal Pradesh: Implications for Genetic Conservation and Crop Diversification

Abstract

Wild edible ferns contribute significantly to the dietary diversity and food security of communities inhabiting the Himalayan region, yet their nutritional potential remains inadequately documented. This study presents a detailed biochemical characterisation of Diplazium esculentum (Retz.) Sw., locally known as 'Lingru', collected from the Seraj Valley in Himachal Pradesh. Our analysis of the dried young fronds revealed a substantial crude protein content of 23.56 g per 100 g, alongside a high dietary fiber content of 35.12 g per 100 g. The fern exhibited a low fat content of 1.23 g per 100 g. Mineral analysis indicated notable concentrations of zinc (36.28 mg/kg), magnesium (29.86 mg/g), and iron (9.98 mg/kg), with a vitamin C content of 39.0 mg per 100 g. Phytochemical screening confirmed the presence of flavonoids, saponins, tannins, and phenolic compounds, while common anti-nutritional alkaloids were absent. Among the extracts tested, a hydroalcoholic solvent yielded the highest total phenolic (4.29 mg GAE/g) and flavonoid (3.17 mg QE/g) contents. This extract also demonstrated the most potent free radical scavenging activity in the DPPH assay, with an IC₅₀ value of 50.53 µg/mL. The findings confirm the traditional use of D. esculentum and highlight its considerable potential as a source of nutrition and bioactive compounds. This underutilised fern warrants further attention for its role in supporting food security and for possible development into value-added health products within Himalayan communities.