## 5 Conclusions  
The results of this paper clearly show the validity of the proposed analytical method of VOC sampling and chemical characterization of the DF obtained from the _Inodorous_ melon. HS-SPME is an extremely high-performance technique and provides highly reproducible results, even for analytes present in low amounts. Indeed, this method is suitable for the effective screening of a wide variety of volatile and semi-volatile compounds related to the aromatic properties of the analyzed materials.  
Different groups of analytes allowed for discrimination of the investigated fiber samples, according to preliminary treatments, as well as aging of the DF. Furthermore, it was possible to highlight that the bleaching treatment with H\({}_{2}\)O\({}_{2}\) reduced the number of VOC groups from 9 to 7, detected at the t\({}_{0}\) time of sample preparation. Conversely, an increment of the quantitative ratios of the oxidized molecules, such as acids--at the detriment of alcohols and ketones--was observed in the bleaching treatment samples. These composition ratios progressively changed and increased even during the fiber aging, reducing the compound classes to four at t\({}_{24}\) months of shelf-life.  
The obtained results could be particularly useful in identifying some target compounds as qualitative and quantitative markers, and can increase knowledge on the influence of treatments and aging time on final compositions of samples from differently treated _Inodorus_ melon fibers.  
For example, acetic esters (ACE), pleasant aromatic molecules, were always present in 'As-it-Is' samples, but they did not persist upon treatment with H\({}_{2}\)O\({}_{2}\). On the contrary, non-acetic ester (NAE) compounds survived to bleaching treatment but disappeared after the long aging time. As far as the aldehyde group (ALD) is concerned, it was possible to note its stability and durability over time, especially for the representative compounds of the C6 subclass. Finally, organic sulfur compounds (SDCs) were identified among the groups of molecules that were not resistant to bleaching treatment; indeed, they are generally classified as off-flavor. Therefore, their elimination could have a very positive effect on the final characteristics of the fiber.  
These results surely represent a benchmark for the application of the proposed method to the study of other vegetable matrices from the _Cucurbitaceae_ family. The possibility of obtaining DF-enriched products represents an important opportunity to meet the growing market demand for dietary fiber and, at the same time, to enhance the recovery of agro-industrial pre-waste materials. Finally, the potential inclusion of this ingredient in many foods may change the needs of processing industries and consumers, as well as enabling more widespread food sustainability.  
Conceptualization, C.D. and L.M.; methodology, C.D. and L.M.; software, V.D. and C.D; validation, L.P., C.D. and V.D.; formal analysis, L.P., A.M. and L.M.; investigation, C.D., L.P., V.D. and A.M.; resources, L.M., V.D. and A.M.; data curation, L.P., C.D. and L.M.; writing--original draft preparation, V.D., L.M. and L.T.; writing--review and editing, C.D. and L.M.; visualization, V.D. and L.M.; supervision, C.D. and L.M.; project administration, L.T. and L.M.; funding acquisition, A.M., L.T. and L.M. All authors have read and agreed to the published version of the manuscript.  
Not applicable.  
Data Availability Statement: Data is contained within the article.  
The authors declare no conflict of interest.  
Samples of the compounds are available from the authors.