【作者】 陈芳；

【导师】 蔡同一；

【作者基本信息】 中国农业大学 ， 农产品加工与贮藏工程， 2003， 博士

【摘要】 二十八烷醇是具有显著抗疲劳功能的天然产物。本论文以米糠为原料，采用SFE-CO₂、酯交换和MD等技术，对其中的二十八烷醇进行提取、精制。通过动物实验对二十八烷醇提取物的抗疲劳功能进行了鉴定，并采用ME技术，获得了适用范围广泛的二十八烷醇微胶囊。实验结果如下： 1．建立了毛细管气相色谱法直接测定二十八烷醇含量的方法。结果表明，在HP-5柱上，内标物TPB、二十八烷醇、三十烷醇与其它高碳脂肪醇之间分离效果好，保留时间分别为8.28min，10.09min和11.81min。该法的线性范围为200-900μg／g，对同一试样平行测定5次的RSD为0.72％。 2．首次应用溶解度参数理论估计米糠中油脂和蜡质在SF中的溶解度。结果表明，油脂比蜡质更容易被SF-CO₂萃取出来。 系统研究了影响SF-CO₂萃取米糠中油脂和蜡质的相关因素，包括物料粒径、溶剂前处理、萃取压力、萃取温度、萃取时间等。并通过正交试验，确定萃取米糠蜡质的最佳参数为：萃取压力50MPa，萃取温度40℃，萃取时间50min；萃取米糠油脂的最佳参数为：萃取压力50MPa，萃取温度40℃，萃取时间35min。与己烷提取相比，SFE对油脂和蜡质的萃取率更高，分别为16.70％和4.25％，且感官品质更好，但两种工艺所获得的提取物在组成上很相似。 3．采用不同溶剂精制糠蜡，产物在得率、熔程、外观以及组成上均有区别。乙酸乙酯是最适合的精制溶剂，精制糠蜡的得率和糠蜡中二十八烷醇的含量均高于其它溶剂。 4．国内首次采用酯交换工艺从精糠蜡中提取高碳脂肪醇。研究了不同溶剂种类、反应时间、蜡醇比、催化剂种类、催化剂浓度、酯交换次数以及萃取时间等因素对高碳脂肪醇提取效果的影响。并以丁醇作为酯交换溶剂，通过正交试验，确定最佳的酯交换工艺参数为：蜡醇比1：12（w／v），反应时间4h，0.2％KOH为催化剂，丙酮萃取6h，其高碳脂肪醇提取物得率为43.99％，二十八烷醇含量为10.89％。与皂化工艺相比，更有利于提高生产率，减轻环境污染。 5．首次系统研究了分子蒸馏温度和真空度对高碳脂肪醇精制效果的影响，采用DORRD，确定最佳的一级蒸馏参数为：温度176℃，真空度1.3Torr，产物中二十八烷醇的含量为28.2％。在蒸馏温度为150℃下进行二级蒸馏，真空度为0.5Torr效果最好，产物中二十八烷醇的含量为37.6％。 6．通过小鼠行为学指标和生化指标的变化，研究二十八烷醇提取物的抗疲劳功能。结果表明，二十八烷醇提取物能够增加小鼠的运动耐力，改善小鼠运动后的多项生化指标，具有抗疲劳功能。 7．研究了二十八烷醇提取物的微胶囊化技术，以阿拉伯胶、β-羟丙基环糊精和麦芽糖（1：1：2）为复合壁材，确定了制备稳定的微胶囊乳化液的参数为：心材：壁材：Tween 80为1：10：5（w：w：v），乳化温度80℃，乳化时间6h。经均质和喷雾干燥后，获得的微胶囊产品水溶性好，MEE和MEY高。 8．在总配方中，添加12.5％的二十八烷醇提取物微胶囊为功能性添加剂，研制了一种泡腾片。采用柠檬酸30％，碳酸氢钠35％，糊精5％的混合物为泡腾片赋形剂，采用柠檬酸15％，阿斯巴甜0.5％，柠檬黄色素1.5％，橙浊0.1％为泡腾片辅料，冲饮时能够产生最佳的泡腾效果和感官品质。更多还原

【Abstract】 Octacosanol has significant antifatigue function. The extraction and purification of octacosanol from rice bran by SF-COa extraction, transesterification and MD were studied in this dissertation. Additionally, the antifatigue function of octacosanol extract was assessed, and a microencapsulated octacosanol was developed. The results were summarized as follows:1. A method for quantitative analysis of octacosanol by GC has been established. The samples were determined in HP-5 column, and TPB was used as the internal standard. The retention times of TPB, octacosanol and triacontanol were 8.28min, 10.09min and ll.Slmin respectively. The calibration curve of octacosanol was linear over a range from 200 u g/ml to 900 u g/ml with a correlation coefficients of 0.992, and the mean coefficient of variation for octacosanol was 0.72%.2. The solubility parameter theory was applied to evaluate solubility of rice bran wax and rice bran oil in SF-COi for first time. It was indicated that the oil was easier to be extracted by SF-CCh-Effects of particle size, pre-treatment by solvents, extracting pressure, extracting temperature, and extracting time on the extraction of wax and oil from rice bran by SF-CO2 were studied. The results of orthogonal experiment using rice bran with particle size of 0.18-0.86mm as material showed that the optimum parameters of wax from rice bran by SF-CO2 extraction were: extracting pressure SOMPa, extracting temperature 40 ℃, extracting time SOmin; The optimum parameters of oil from rice bran by SFE were: extracting pressure 50MPa, extracting temperature 40℃, extracting time 30min. Under the above conditions the yields of wax and oil reached 4.25% and 16.70% respectively. The wax and oil had higher yield and better sensory quality by SF-CO2 extraction in comparison with by n-hexane extraction, but the compositions of extracts were similar.3. Effects of different solvents on the refining of rice bran wax were studied. The results indicated that the composition, yield, melting point and sensory quality of refined rice bran wax were different. Acetyl acetate was a suitable refining solvent, and the wax yield and the octaconsanol content were the highest, which reached 57.8% and 12.5% respectively.4. Effects of solvent, reaction time, ration of wax to solvent, kind and concentrate of catalyst, reaction degree and extracting time on the extraction of higher aliphatic alcohol mixtures from refined rice bran wax by transesterification were studied. The results of orthogonal experiment showed that the yield of higher aliphatic alcohol mixture and octacosanol content were the highest when ration of wax to n-butynol was 1:12 (w/v), catalyzed by 0.2% KOH for 4h and extracted for 6h by acetone. Transesterification was beneficial to surrounding protection in comparison with saponification.5. Higher aliphatic alcohol mixtures were purified by MD to increase octacosanol content. Influence of distilling temperature and distilling vacuum degree on the purification were studied systematically for first time. The results of DORRD showed that optimum distilling temperature was 176癈, optimum distilling vacuum degree was 1.3Torr in the first MD, and the octacosanol content increased to 28.2%. The optimum distilling vacuum degree was O.STorr under 150癈 in the second MD,and the octacosanol content increased to 37.6%.6. Effects of octacosanol extract on behavior and biochemical index of swimming mice were examined. The increase of sport stamina was observed, in the meanwhile, some biochemical index also have been improved. Octacosanol extract would be considered to have an antifatigue bioactivity.7. A novel functional additive was developed by ME using acacia gum, P-HP-CD and maltose (1:1:2) as shell materials and octacosanol as core material. The optimum parameters of preparing stable emulsifying liquid for spray drying were: ratio of core material to shell material to Tween 80 was 1:10:5 (w:w:v), emulsifying temperature was 80℃, emulsifying time was 6h. The microcapsule produ更多还原