超声辅助酶法提取咖啡果皮果胶工艺的优化及其理化特性分析

Optimization of Ultrasound-assisted Enzymatic Extraction of Pectin from Coffee Peel and Analysis of Its Physicochemical Properties

为研究咖啡果皮中果胶的提取工艺和理化特性,以云南小粒咖啡果皮为原材料,在单因素实验的基础上采用响应面设计优化果胶的超声辅助酶法提取工艺,采用傅里叶红外光谱(Fourier Transform Infrared Spectroscopy,FT-IR)检测粗果胶的官能团组成;通过AB-8大孔树脂、Sevage法脱色脱蛋白纯化粗果胶,并比较纯化前后果胶理化特性的差异。结果表明,最佳提取条件为:纤维素酶添加量1.49%,酶解时间45.78min,超声时间19.30min,得率为16.42%。FT-IR结果显示咖啡粗果胶含有典型的多糖结构。纯化后,果胶总糖含量增加了17.51%,多酚、蛋白质含量、酯化度和乙酰化度分别减少了72.41%、23.53%、77.43%和91.16%。与粗果胶相比,纯化可增加果胶持水性(20.05g/g)持油性(8.13g/g)、乳化性(48.06%)和乳化稳定性(45.59%),分别增加了470%、52.25%、26.31%和9.64%,但是降低了咖啡果胶的起泡性和泡沫稳定性。该研究为云南小粒咖啡果皮果胶的开发利用提供了试验基础。

To investigate the extraction process and physicochemical properties of the pectin from coffee peel,the Yunnan arabica coffee peel was used as the raw material.Based on single factor experiments,response surface design was employed to optimize the ultrasound-assisted enzymatic extraction of pectin.Fourier transform infrared spectroscopy(FT-IR)was used to identify the functional groups of the pectin.Crude pectin was purified through decolorization and deproteinization by the AB-8 macroporous resin and Sevage method.The physicochemical properties of the pectins before and after purification were compared.The results showed that the optimal extraction conditions were as follows:cellulase addition,1.49%,enzymolysis time,45.78 min;ultrasonic time,19.30 min.The resulting extraction yield was 16.42%.FT-IR results showed that the crude pectin had a typical polysaccharide structure.After purification,pectin's total sugar content increased by 17.51%.The polyphenol content,protein content,esterification degree and acetylation degree decreased by 72.41%,23.53%,77.43% and 91.16%,respectively.Compared with the crude pectin,the purified pectin had an increased water-holding capacity(20.05 g/g),oil-holding capacity(8.13 g/g),emulsifying capacity(48.06%)and emulsion stability(45.59%)(increased by 470%,52.25%,26.31% and 9.64%,respectively),but a decreased foaming ability and foam stability.This study provides an experimental basis for the development and utilization of pectin from the pericarp of Yunnan arabica coffee.