Unlocking the nutritional and economic potential of cucurbitaceae seeds: a comprehensive review of their chemical composition, bioactive compounds, uses and global significance.

Cucurbitaceae fruits are cultivated globally, but their seeds are mostly a waste product, although compositional data suggest real potential for food, nutraceutical and industrial uses. Existing reviews generally summarize the reported values without discussing the variability among studies or providing an explanation of the status of the mechanistic evidence. The present paper attempts to fill this gap by reviewing the composition, bioactive profile and oil quality of Cucurbitaceae seeds based on the consistency of the existing literature. The seeds are shown to be a genuine source of high-quality protein, essential fatty acids dominated by linoleic acid and a favourable complement of phenolic compounds, tocopherols and phytosterols with antioxidant activity supported across multiple in vitro systems. Their oils show physicochemical properties suitable for food, cosmetic and pharmaceutical use. The review also points out that much of the reported variation in phenolic content, flavonoid content and oil yield reflects methodological fragmentation rather than genuine biological differences. Based on this evidence, specific valorisation directions are outlined, including the circular use of seed by-products in producing regions where they are currently wasted. Mechanistic and analytical gaps, particularly the scarcity of in vivo data, that need to be filled before Cucurbitaceae seeds become an established component of the functional food and bioeconomy landscape are highlighted.