In this study, the trend of VOCs of dietary fiber samples, coming from three different watermelon cultivars Citrullus lanatus L. (variety Gavina®®, Crimson Sweet, and Asahi Miyako) was investigated. This foodstuff, obtained as a by-product of residual agri-food production, has gained increasing attention because of its many bioactive components and high dietary fiber content. The result is a fibrous material for specific applications in food manufacturing, such as corrector for some functional and technological properties. In this study, a method based on headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was used to characterize the aromatic profiles of the dried raw materials. Therefore, the VOCs of the samples of the three cultivars were investigated. Experimental results have shown that watermelon fibers generate VOCs, which can be grouped into six common classes of analytes. The different distributions of the identified compounds made it possible to effectively differentiate the three cultivars studied based on their peculiar aroma profiles. In particular, Gavina®® fiber is distinguished by the high content of terpenes, Asahi Miyako by the presence of aldehydes generated as fatty acid metabolites, and Crimson Sweet by the higher content of acetyl esters.
Keywords: HS-SPME-GC-MS; biorefinery; dietary fibers; food waste; nutrients recovery; recycle; volatile compounds; watermelon.