Optimization of Ultrasound Assisted and Maceration Extraction of Bioactive Compounds of Sardasht Black Grape residue by using Response Surface Methodology

Abstract

Sardasht black grape (Vitis Viniferae cv. Rash) is one of the most important grape cultivars in west Azerbaijan province in Iran that mainly used for grape juice production. Black grape residues are a cheap source of bioactive compounds. In this research ultrasound-assisted (UAE) and maceration extraction (ME) were applied for bioactive compounds extraction of Sardasht black grape residues.A central composite design was used to obtain the optimal conditions of UAE and ME; the effects of operating conditions (temperature and time) on phenolic compounds, anthocyanin content and antioxidant activity were studied through response surface methodology (RSM). Optimized conditions were as follows: extraction time was 24 h, and temperature was 35°C for ME and 55°C and 15 min for UAE.Under these conditions the phenolic compounds, anthocyanins and antioxidant activity obtained by ME and UAE methods were 96.779 mg GAE/100 ml, 118.345 mg/L, 55.49% and 114.115 mg GAE/100 ml, 121.645 mg/L, 64.89%, respectively.This study provides evidence that UAE is an effective technique for the extraction of bioactive compounds from Sardasht black grape residues.