为优化十六烷基三甲基溴化铵（CTAB）辅助提取血柚皮果胶工艺，在单因素实验基础上，选取CTAB浓度、pH、提取温度、提取时间为自变量，果胶提取率为响应值，采用Box-Behnken实验设计方法，研究各自变量及其交互作用对果胶提取率的影响，并利用Design-Expert8.05b软件，建立了果胶提取率与各因素的二次多项式模型。结果表明，CTAB辅助提取血柚皮果胶的最佳工艺条件为CTAB浓度0.62%、pH 2.1、提取温度56 ℃、提取时间93 min，该条件下果胶提取率为20.85%，与预测值的相对误差为0.28%，表明该模型有效。所得的果胶黏度为58.2×10-3 Pa·S，甲氧基含量为6.47%，酯化度为38.9%，灰分为0.82%，总半乳糖醛酸果胶含量为85.7%，其主要理化性质完全符合QB2484—2000标准，该果胶是一种低甲氧基果胶，可作为一种增稠剂使用。
The process of CTAB-assisted extraction of pectin from blood pomelo peel was optimized. Based on the single-factor experiments, selecting concentration of CTAB, pH, temperature and time as independent variables and the extraction yield of pectin as response value, the effects of each independent variable and their interactions on the extraction yield were studied by Box-Behnken design. The quadratic multinomial model of each factor and the yield was set by Design-Expert 8.05b software.The results showed that the optimal extraction conditions of pectin from blood pomelo peel were: CTAB concentration 0.62%, pH 2.1, temperature 56 ℃ and time 93 min. The yield of pectin could be up to 20.85% under the optimal extraction condition, the relative error was 0.28% compared to the predictive value, which indicated the feasible model fitted well with the experimental data. The pectin showed a viscosity of 58.2×10-3 Pa·S, content of methoxy group 6.47%, degree of esterification 38.9%, ash content 0.82%, content of total galacturomic acid pectin 85.7%, which accorded with the standard of QB2484-2000. The pectin was a kind of low methoxy pectin and could be used as thickener.