Isolation of phenolic compounds from organic waste in wine production

Cilj ovog istraţivanja bio je ispitati utjecaj dvaju parametara konvencionalne ekstrakcije: vrijeme ekstrakcije i udio kiseline u otapalu, na izolaciju fenolnih spojeva (proantocijanidini, hidroksicimetne kiseline te ukupni flavonoli) iz pokoţice grožđa sorte Teran izdvojene iz komine nakon proizvodnje vina. Ekstrakcija je provedena uz primjenu 50% vodene otopine etanola, te s 50% vodene otopine etanola koja sadržava 0.5 i 1% klorovodične kiseline, kroz vrijeme ekstrakcije od 30, 45 i 60 minuta. Fenolni spojevi određivani su spektrofotometrijski. Povećanje udjela klorovodične kiseline u otapalu za ekstrakciju utjecalo je na povećanje prinosa svih istraživanih skupina fenolnih spojeva. Količina hidroksicimetnih kiselina i flavonola bila je u gotovo svim uzorcima najveća nakon 45 minuta, a proantocijanidina nakon 60 minuta ekstrakcije.The aim of this study was to investigate the influence of two parameters of conventional extraction: extraction time and addition of acid in solvent, to the isolation of phenolic compounds (proanthocyanidins, hydroxycinnamic acids and total flavonols) from the grape skin of grape variety Teran, separated from the pomace after wine production. Extraction was made with the use of 50% aqueous ethanol and with 50% aqueous ethanol containing 0.5 and 1% hydrochloric acid, through the extraction time of 30, 45 and 60 minutes. Phenolic compounds were determined by spectrophotometric method. Increasing the content of hydrochloric acid in a solvent for extraction contributed to the increase of all investigated groups of phenolic compounds. The amount of hydroxycinnamic acids and flavonols, in almost all samples was the highest after 45 minutes and after 60 minutes for proanthocyanidins