Comparative nutritional and phytochemical screening of a wild edible fern: Diplazium maximum (D. Don) C. Chr. from north-western Himalayan regions of Himachal Pradesh

A comparative assessment of Diplazium maximum (D. Don) C. Chr. young edible fronds revealed significant variations (p ≤ 0.05) in nutritional and bioactive properties across Shimla (SA), Mandi (SB) and Chamba districts (SC) of Himachal Pradesh. SC and SB fronds exhibited the highest content of moisture (92.78 %), total energy (1353.61 KJ/100 g), crude fat (2.86 %), total ash (12.64 %) and total carbohydrates (50.78 %), dietary fiber (40.54 %), total soluble sugar (1.60 %), respectively. The significantly highest (p ≤ 0.05) protein (28.02 %), calcium ( Ca 0.12 %), iron (Fe 0.0157 %), copper (Cu 0.0026 %) and manganese (Mn 0.0021 %) content was recorded at SA. Antioxidant profiling showed the significant activity in SB hydro-alcoholic extract, demonstrating the lowest IC50 values (53.31 and 50.69 µg/mL) for 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) assays corresponding to the highest total phenolics (TP=90.71 mg GAE/g) and flavonoids (TF=75.65 mg QE/g) concentration. Phytochemicals screening also confirmed the presence of alkaloids, phenolics, flavonoids, terpenoids, glycosides, tannins and saponins. Total chlorophyll (50.53 µg/100 g) and total carotenoids (7.48 µg/100 g) content varied significantly (p ≤ 0.05) across all sites, being highest in SB and SC fronds respectively. Fatty acids profiling through gas chromatography-mu ass spectrometry (GC-MS) revealed dominance of methyl palmitate (85.5 %) and methyl lignocarate (18.97 %). Overall, D. maximum fronds exhibit strong nutritional, bioactive and antioxidant potential, supporting their value as a sustainable wild edible resource for enhancing food security and future nutraceutical applications.