Volatile Aroma Compounds of Gavina® Watermelon (Citrullus Lanatus L.) Dietary Fibers to Increase Food Sustainability

To deal with climate emergency and reduce environmental impact, agro-industrial wastes are gradually gaining interest and are being used for new products and applications. The large production of watermelons represents an opportunity because of the many byproducts that can be transformed into innovative and valuable foodstuffs. In this study, we examined the lycopene-rich whole dietary fiber (WDF) obtained from the watermelon pomace of a peculiar cultivar, Gavina® (Oristano, Italy) a seedless fruit from Sardinia (Italy). The volatile chemical composition of the WDF was investigated using Solid-Phase Microextraction-Gas Chromatography/Mass Spectrometry (SPME-GC/MS). The aim was to follow the evolution of the Volatile Organic Compounds (VOCs) fraction during storage and verify its stability over time. Since watermelon is an excellent source of carotenoids, their byproducts were the most abundant VOCs of the freshly prepared samples, but their overall abundance decreased significantly during storage. The opposite trend was observed for acids and aldehydes, whose increase over time is related to amino acid degradation. Freshly prepared WDF can be used in the food industry as an antioxidant-rich dietary fiber that imparts a characteristic and pleasant aroma. Over time, its aroma profile and carotenoid content change considerably, reducing its health properties and limiting its potential application as a natural flavor.