Nutritional Properties of Edible Flowers from Five Pumpkin (Cucurbita sp.) Species

Edible pumpkin flowers represent a promising but still underutilized source of nutrients and bioactive compounds. Despite their traditional culinary use in various regions of the world, comprehensive studies comparing the nutritional and chemical composition of flowers from different Cucurbita species are limited. This study conducted a detailed chemical analysis of flowers from five pumpkin species: Cucurbita maxima (giant pumpkin), C. pepo (summer squash), C. moschata (butternut squash), C. ficifolia (fig-leaf gourd), and C. argyrosperma (cushaw squash). The analyses included the determination of basic nutritional components, amino acids, minerals, vitamins, and fatty acid profiles using standard analytical methods (AOAC, ISO, and HPLC). Significant interspecific differences were observed. The flowers of butternut squash exhibited the highest protein and fat contents, while the flowers of cushaw squash contained the largest amounts of dietary fiber and total sugars. Flowers of giant pumpkin were distinguished by their elevated contents of vitamin C and β-carotene. Amino acid analysis revealed a rich protein profile, particularly in cushaw squash, characterized by high lysine and cysteine levels, whereas fig-leaf gourd contained the greatest amounts of leucine and isoleucine. The fatty acid composition was dominated by oleic, stearic, and myristic acids, while a considerable proportion of linoleic acid (PUFA) indicated potential health benefits, such as anti-inflammatory effects. Mineral analysis showed that giant pumpkin was richest in potassium, summer squash in zinc, and butternut squash in calcium and sodium. The findings confirm that pumpkin flowers are a valuable source of nutrients and bioactive compounds. Their composition highlights their potential as functional food ingredients and as raw materials for use in the dietary, food, and pharmaceutical industries. Further studies on bioavailability and antioxidant capacity are recommended to better define their nutritional and functional value.