This report presents a comparative analysis of grape pomace in three forms: raw, as a vitreous biomaterial, and as an ultrafine powder. As the matrix undergoes transformation, the levels of bioactive compounds increase dramatically. Total polyphenol content rises from 1,015.7 mg GAE/100 g in raw pomace to 2,693.2 mg in the vitreous biomaterial, reaching 3,925.8 mg in the ultrafine powder—an overall increase of +287% compared to the original material. In parallel, antioxidant capacity (ORAC) increases from 15,235.8 to 38,990.5 µmol TE/100 g, representing a +256% enhancement. This multiplier effect results from the progressive breakdown of cell wall polymers during the vitrification process, followed by a more efficient release of bioactive compounds through particle size reduction. Together, these processes unlock previously trapped functional fractions, significantly improving their bioavailability and functional potency.
