摘要
In this study, pectin was extracted from grapefruit peels with hydrochloric acid and precipitated with 95% ethanol solution and 5% tartaric acid. The physical and chemical properties of pectin obtained were analyzed, including color, texture, degree of esterification, and water solubility. The effects of peel to sol- vent ratio, pH of the solvent, extraction temperature and extraction duration on pectin extraction rate were investigated. On the basis of single-factor experiments, an L9 （34） orthogonal experiment was performed to screen the optimal extraction conditions. According to the results, the optimal combination of technical parame- ters was A1B3 C1 D3, i. e. , solid to liquid ratio 1：40 （g： ml）, pH 2.0, extraction duration 70 rain, extraction temperature 90 ℃. The average pectin extraction rate was 68.60% ; the color of pectin extracted under the optimal conditions varied from milky white to light yellow; the degree of esterification of pectin extracts was 65. 71% ; the extracted pectin exhibited good water solubility. Key words Pomelo peel; Pectin extraction; Optimum conditions; Esterification degree; Water solubility
In this study, pectin was extracted from grapefruit peels with hydrochloric acid and precipitated with 95% ethanol solution and 5% tartaric acid. The physical and chemical properties of pectin obtained were analyzed, including color, texture, degree of esterification, and water solubility. The effects of peel to sol- vent ratio, pH of the solvent, extraction temperature and extraction duration on pectin extraction rate were investigated. On the basis of single-factor experiments, an L9 （34） orthogonal experiment was performed to screen the optimal extraction conditions. According to the results, the optimal combination of technical parame- ters was A1B3 C1 D3, i. e. , solid to liquid ratio 1：40 （g： ml）, pH 2.0, extraction duration 70 rain, extraction temperature 90 ℃. The average pectin extraction rate was 68.60% ; the color of pectin extracted under the optimal conditions varied from milky white to light yellow; the degree of esterification of pectin extracts was 65. 71% ; the extracted pectin exhibited good water solubility. Key words Pomelo peel; Pectin extraction; Optimum conditions; Esterification degree; Water solubility
基金
Supported by Project of Education Department of Jiangxi Province(JXJG-08-4-27)
