“赤霞珠”葡萄皮渣中原花青素的提取工艺研究

Orthogonal Test Design for Optimization of the Ethanol Extraction and the Microwave-assisted Ethanol Extraction of Proanthocyanidins from Cabernet Sauvignon Grape Skin

研究乙醇浸提法和微波辅助浸提法提取"赤霞珠"葡萄皮渣原花青素的工艺。乙醇浸提法研究提取时间、提取温度、料液比、乙醇浓度四个因素对原花青素提取率的影响;微波辅助浸提法研究微波时间、乙醇浓度、料液比三个因素对原花青素提取率的影响。乙醇浸提法的最佳提取工艺为:提取时间55min,提取温度50℃,料液比1:8.5(g/ml),乙醇浓度55%,提取率为2.61%;微波辅助浸提法的最佳提取工艺为:微波功率320W,微波时间30s,乙醇浓度50%,料液比1:13(g/ml),50℃恒温水浴中浸提30min,提取率为3.99%。在最佳提取工艺条件下研究pH值对原花青素提取率的影响。乙醇浸提法和微波辅助浸提法分别在pH4.5和pH5时,原花青素提取率最大,提取率分别为2.67%和4.11%,表明酸提高了原花青素的提取率。

Effects of extraction duration, temperature, solid/liquid ratio and concentration of aqueous ethanol solution on yield of proanthocyanidins from Cabemet Sauvignon grape skin extracted individually with ethanol were studied by single factor test, as well as effects of microwave radiation duration, concentration of aqueous ethanol solution and solid/liquid ratio on yield of proanthocyanidins extracted with ethanol under the assistance of microwave. Based on the results of single factor test, the two extraction technologies were optimized by orthogonal test design. Under optimized conditions for individual ethanol extraction [temperature, 50 ℃; extraction duration, 55 min, solid/liquid ratio, 1：8.5 （g/ml）; and concentration of aqueous ethanol solution, 55%], the yield of proanthoeyanidins was 2.61%; under optimized conditions for microwave-assisted extraction [microwave radiation power, 320 W; microwave radiation duration 30 s; concentration of aqueous ethanol solution, 50%; and solid/liquid ratio, 1：13 （g/ml）], the yield of proanthocyartidins was 3.99%. When acidic ethanol solutions at pH 4.5 and 5.0 were used to extract proanthocyanidins by the two optimized technologies, the yields of proanthocyanidins were 2.67% and 4.11%, respectively, indicating that the addition of acid is favorable to increase the yields of proanthocyanidins.