超声辅助碱性过氧化氢法提取琯溪蜜柚幼果纤维素的工艺优化及结构表征

采用超声辅助碱性过氧化氢法对琯溪蜜柚幼果中的纤维素进行提取研究，在单因素实验基础上，以纤维素纯度作为指标，利用Design-Expert 8.0设计中心组合试验，采用响应面分析法优化纤维素的提取工艺，并对纤维素进行了红外光谱分析和扫描电镜分析。结果表明，超声功率的改变对纤维素纯度和得率的影响并不显著，水浴温度、超声时间、过氧化氢溶液体积分数、氢氧化钠溶液质量浓度均对纤维素纯度和得率影响显著；优化的最佳提取条件为:超声功率200 W，超声时间40 min，水浴温度80 ℃，H₂O₂体积分数0.9%，NaOH质量浓度9%。在此条件下纤维素纯度预测值为88.48%，实测值为88.95%，该模型理论预测值与实际值拟合效果良好，此条件下纤维素得率为17.65%。红外分析表明纤维素制备成功，扫描电镜分析发现纤维素较处理前的琯溪蜜柚幼果表面结构疏松，沟壑较深，X-射线衍射分析表明纤维素具有I型结构，结晶度为44.26%。本研究优化了琯溪蜜柚幼果纤维素的超声辅助碱性过氧化氢提取工艺，耗时短、纤维素纯度高，为琯溪蜜柚幼果的利用及食品源纤维素的开发提供参考。

Optimization of Ultrasonic Assisted Alkaline Hydrogen Peroxide Extraction and Structural Characterization of Cellulose from Young Fruit of Guanxi Honey Pomelo

The extraction of cellulose from the young fruit of Guanxi honey pomelo was studied by ultrasonic assisted alkaline hydrogen peroxide method. On the basis of single factor experiments, taking the cellulose purity as the index, the combination experiment of Design-Expert 8.0 design center was used to optimize the extraction process of cellulose by response surface analysis, the cellulose was analyzed by IR and SEM. The results showed that the change of ultrasonic power had no significant effect on the purity and yield of cellulose, but water bath temperature, ultrasonic time, volume fraction of hydrogen peroxide solution and mass concentration of sodium hydroxide solution had significant effects on the purity and yield of cellulose. The optimum extraction conditions were as follows: Ultrasonic power 200 W, ultrasonic time 40 min, water bath temperature 80 ℃, H₂O₂ volume fraction 0.9%, NaOH mass concentration 9%. Under these conditions, the predicted value of cellulose purity was 88.48%, and the measured value was 88.95%, under this condition, the yield of cellulose was 17.65%. Infrared analysis showed that cellulose was successfully prepared. SEM analysis showed that the surface structure of cellulose was looser and the gully was deeper than that of Guanxi honey pomelo young fruit before treatment. X-ray diffraction analysis showed that cellulose had type I structure and the crystallinity was 44.26%. This experiment optimized the ultrasonic assisted alkaline hydrogen peroxide extraction process of cellulose from young fruits of Guanxi honey pomelo. It was an efficient and easy to popularize cellulose preparation method, which would provide a reference for the utilization of young fruits of Guanxi honey pomelo and the development of cellulose.