Effect of different drying methods on the content of polyphenolic compounds of red grape skins

The aim of this work was to determine the effect different drying treatments: freeze-drying, room-drying, and oven-drying on grape phenolic composition 'Regent' 'Cabernet Sauvignon' varieties. After drying, samples were grounded, submerged ultrasound-assisted extraction, analyzed with high-performance liquid chromatography (HPLC). This study demonstrated that use methods significantly affects content polyphenols in skins extracts. greatest anthocyanins-diglucoside preserved using i.e. 15706.86 mg/kg for 'Regent', while anthocyanins-monoglucoside best by 216778.68 9220.30 Sauvignon', respectively. highest flavonol glycosides (2583.04 1429.64 respectively), hydroxycinnamic acids (1303.31 544.88 stilbene (2321.52 79.36 respectively) observed oven-dried samples. By applying freeze-drying most optimal flavan-3-ol preserved. Contents polyphenolic compounds after 6 months storage almost identical those immediately drying. rate degradation room-dried it moderate freeze-dried ones. results experiment demonstrate is necessary dry ways obtain a certain group compounds. application method determined goal final dried product terms compounds; thus, obtained could have an scientific research commercial purposes as well.