Spent grape pomace as a still potential by-product

This research consisted of the determination of several phenolic compound and fatty acid contents of the grape seeds and skins obtained from pomace PRE and POST distillation. The quantification of flavan-3-ol composition, the determination of the mean degree of polymerisation (mDP) of the condensed tannins and the estimation of their antiradical activity have been also realised. The distillation process applied did not seem to significantly affect the fatty acid distribution of extracted oils. Conversely, the antiradical activity of both seeds and skins changed. Heating significantly decreased the seeds' activity, while increased the skins' activity to around 50% compared to PRE sample. The conclusion from this study is that despite the degradation caused by the drastic conditions, many interesting, valuable compounds are still present in the extract from the waste of this process, which makes it a useful matter for a better exploitation than as fertiliser or for producing renewable energy.