engleski

Polyphenolic profile of enriched grape juice

Grape is a fruit with an exceptional composition of polyphenols. However, after juice processing most of phenolic compounds remain in the by- product grape pomace, and only part of them pass to juice. The aim of this research work was to determine the potential of grape juice enrichment process with polyphenols extracted from different varieties of grape pomace. The autochthonous white grape varieties of Kastavština were used for the juice production while the polyphenolic extracts from grape pomace were obtained by extraction with 70% ethanol and by ultrasound treatment. The polyphenolic profile of enriched juices was determined by liquid chromatography coupled to mass spectrometry (LC-MS / MS). With the analysis of individual polyphenols, total phenols were also spectrophotometrically determined. The obtained results showed that the grape variety significantly influences the polyphenolic profile of the juice, but it has also been observed that the variety of pomace affects the overall polyphenolic profile both qualitatively and quantitatively. The phenolic- enriched grape juices proved to be a good source of bioactive compounds and an interesting product with potential grape-derived health benefits.

grape juice ; grape pomace ; polyphenols ; LC-MS/MS

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