Physicochemical and Qualitative Phytochemical Analysis of Pumpkin (Cucurbita spp.) Seeds

Abstract

Introduction: Pumpkin seeds (Cucurbita pepo, Cucurbita maxima, and Cucurbita moschata) are widely consumed agro-industrial by-products that are often discarded despite their reported nutritional and pharmacological potential. Aim: The present study aimed to evaluate the physicochemical characteristics and preliminary phytochemical profile of pumpkin seed samples collected from the local market of Varanasi, India. Materials and Methods: Three pumpkin seed samples obtained from different vendors were subjected to proximate and phytochemical analyses. Moisture content was determined by loss on drying at 105°C. Total ash, acid-insoluble ash, water-insoluble ash, and water-soluble ash were estimated using standard analytical procedures. Ethanolic extracts of powdered seeds were prepared using Soxhlet extraction, followed by qualitative phytochemical screening for major bioactive constituents using standard chemical tests. Results: The average moisture loss of pumpkin seeds was 5.62%, indicating moderate moisture content reduction under controlled drying conditions. The average total ash content was 4.46% for Batch I and 4.43% for Batch II, reflecting consistency in mineral composition across samples. Acid-insoluble ash (1.48%), water-insoluble ash (4.02%), and water-soluble ash (0.41%) indicated low levels of extraneous inorganic impurities and moderate mineral solubility characteristics. Phytochemical screening of ethanolic extracts revealed the presence of protein in all samples, while alkaloids, carbohydrates, starch, flavonoids, terpenoids, saponins, steroids, tannins, and glycosides were absent. Resin was detected only in Sample I. Conclusion: The findings indicate that the analyzed pumpkin seed samples possess stable physicochemical properties with appreciable protein content. However, the absence of several key phytochemicals in the ethanolic extracts suggests possible influence of factors such as solvent specificity, seed maturity, storage conditions, or varietal differences. Further detailed quantitative and advanced chromatographic analyses are recommended to better characterize the bioactive profile of pumpkin seeds.