【作者】 陈精明；

【导师】 包宗宏；

【作者基本信息】 南京工业大学 ， 化学工程， 2003， 硕士

【摘要】 双液相溶剂萃取技术是近年来开发出的新型油脂浸出技术，应用此技术处理油菜籽，可以在制取高质量毛油的同时，得到色浅、味淡、流动性好、蛋白质含量高、硫甙含量低的菜籽饼粕。双液相溶剂萃取技术从实验室研究到工业化应用，有许多问题需要探索和解决。本文对双液相溶剂萃取过程的动力学进行了研究，测得了菜油和硫代葡萄糖甙(以下简称硫甙)的萃取动力学数据，建立了萃取传质模型，得到了菜油和硫甙在油菜籽中的扩散系数，从而为双液相溶剂萃取技术的工业放大提供参考。为此进行的具体工作如下：(1) 建立适用于双液相溶剂萃取油菜籽饼粕的硫甙分析方法。通过实验证实了氯化钯法对双液相溶剂萃取的菜籽饼粕适应性良好，完全可以用于硫甙总量的测定。作者比较了氯化钯法在450nm和540nm处比色的测定效果，发现在450 nm处测定的平均误差小于在540 nm处的。另外，选用由HPLC法测定硫甙浓度在13.3～110.3 μmol/g范围内的8个油菜籽饼粕样品，作为标准样品，由此建立工作曲线。结果平均误差为6 μmol/g左右，最大误差约10μmol/g，能满足实验测定的需要。(2) 分析了民用磨磨碎油菜籽的颗粒粒度分布情况。通过对磨碎后的油菜籽颗粒进行筛分，测得磨碎时间分别为30 s、60 s、90 s、180 s的油菜籽颗粒名义粒径分别为0.755 mm、0.499 mm、0.424 mm、0.326 mm。这些粒径大小的油菜籽，能满足考察粒径大小对菜油和硫甙萃取速率影响的实验需要。(3) 考察了对萃取过程有影响的各种因素。在不同的萃取条件下，测定了菜油和硫甙在不同时间下的萃取率，发现减小油菜籽粒径、提高萃取温度、提高石油醚相溶剂比(ml石油醚/g菜籽)能促进菜油的萃取。减小油菜籽粒径、提高萃取温度、提高甲醇相溶剂比(ml甲醇/g菜籽)、提高石油醚相溶剂比能促进硫甙的萃取。作者分析了各种因素的影响，进行了机理的初步探讨。(4) 从油菜籽颗粒角度出发，根据菲克第二定律，对半径为R各向同性的球形油菜籽颗粒作扩散过程分析，建立萃取传质模型：并对模型进行了进一步修改，提出扩散系数随萃取时间的变化率为：<WP=6>实验数据对模型参数进行回归分析，得到双液相溶剂萃取条件下菜油和硫甙在油菜籽中的扩散系数平均值数量级为10－13 m2/s。(5) 分析了扩散系数与萃取温度的关系，指出了扩散系数与萃取温度满足阿仑尼乌斯定律，求得了菜油和硫甙在油菜籽中扩散的表观活化能分别为4.512 kJ/mol、0.7 kJ/mol。更多还原

【Abstract】 Two-liquid phase solvent extraction technology is a novel method. Two improved products, a proteinaceous meal with reduced glucosinolates and a high quality triglyceride oil, both acceptable as feed and food ingredients could be yielded by the process. The meals were free-flowing, light in color, bland in taste and rich in proteins. Two-liquid phase solvent extraction technology has been developed since 1980’s and many achievements were acquired in the labs, but there were some troubles in the industrialization. In this paper, the kinetics of extracting both of oil and glucosinolates from rapeseed particles with two-liquid phase solvent system was studied. Valuable data of the mass transfer through a serial of experiments were obtained. A mass transfer model was set up to describe the extraction process. The diffusion coefficients of the rapeseed oil and glucosinolates within rapeseed particles, which would be useful in the scale up of the process, could be calculated by the model. During the periods to finish the experimental tasks, following as main items were done. (1) The method to determine the glucosinolates in rapeseed meal extracted by two-liquid phase solvent system was improved. Palladium test was proved to be suitable for detection the total glucosinolates in rapeseed meal. Both wavelengths of 450nm and 540nm were test and found that detection with 450nm would gaine a minor mean error. Further more, some standard meal which the glucosinoates concentration were 13.3～110.3μmol/g detected by HPLC were selected and used to set up the standard curve. Finally, a mean error of 6μmol/g was obtained and used to determine the glucosinolates with the wavelength of 450nm. (2) The distribution of particle size of the ground rapeseed was determined. The mesh analysis was completed for the rapeseed particles, which were ground in 30, 60, 90, and 180s and the nominal diameters of these ground rapeseed were 0.755, 0.499, 0.424 and 0.326 mm. (3) Many factors influencing the extracting rate in two-liquid phase solvent extraction were studied. It was concluded that minor rapeseed diameter, higher temperature and hexane ratio were benefit for the rapeseed oil extraction. Also minor rapeseed diameter, higher<WP=8>temperature, higher hexane ratio and methanol ratio were benefit for the glucosinolates extraction.(4) A model as follows based on differential mass balances performed along the radial of the isotropic rapeseed particle was proposed: Regression for the parameters of the model using the rapeseed oil and glucosino- lates extraction rate data was completed. At last, the diffusion coefficient of the extraction process was obtained and their order of magnitude was 10－13 m2/s.(5) The relationship between the diffusion coefficient and temperature could be expressed by Arrhenius law and the activation energy of the extraction process was calculated.更多还原