【作者】 陈静静；

【导师】 孙志高；

【作者基本信息】 西南大学 ， 农产品加工与贮藏工程， 2009， 硕士

【摘要】 苧烯是柑桔、蔬菜及香料中广泛存在的一种单环单烯烃,它具有抗癌、抑菌等生理功能,并且在香料工业、日化工业和食品工业上有广泛的应用,具有广阔的发展前景。本论文以柑桔精油和柑桔皮渣为原料,采用减压蒸馏萃取、水蒸汽蒸馏萃取、超临界CO₂萃取和化学纯化等技术,对苧烯进行了提取、纯化,获得了高纯度的苧烯;并对不同柑桔品种果汁和果皮、浓缩橙汁和鲜橙汁中苧烯的含量进行了测定和对比分析,获得了柑桔中苧烯含量分布的统计数据。论文重点研究了各种不同的工艺条件对提取纯化效果的影响,并确定了适宜的工艺参数。实验结果如下:1.利用蒸馏滴定法对90个不同柑桔品种果汁和果皮中苧烯含量进行了分析测定。结果表明,不同柑桔种类果汁中苧烯含量不同,甜橙、宽皮柑桔、杂柑和柚果汁中苧烯平均含量分别为0.0824‰、0.2785‰、0.1063‰、0.0450‰。实验对企业生产的9个浓缩果汁样品和11个鲜榨汁样品中苧烯含量进行了研究,结果发现浓缩果汁中苧烯的含量均很低,平均含量为0.0018‰;鲜榨汁中苧烯的平均含量为0.1125‰。并且经过贮藏后柑桔果汁和果皮中苧烯含量均下降;不同柑桔品种其果皮中苧烯的含量差异较大,甜橙类、柚类、杂柑类果皮中苧烯平均含量分别为4.527g/kg、2.115g/kg、4.994g/kg。不同采收期的柑桔品种,其苧烯含量也各有差异。2.研究了两种不同的方法对食品级苧烯和工业级苧烯的提取。影响减压蒸馏技术对食品级苧烯提取效果的相关因素,包括真空度、蒸馏时间、蒸馏温度。以冷磨橙油为原料,通过正交实验,确定了减压蒸馏萃取苧烯的适宜工艺组合:真空度为0.08MPa、蒸馏时间为10min、料液温度为170℃,所得苧烯浓度达到了95.46%。同时研究了水蒸汽蒸馏技术对工业级苧烯提取效果的影响因素,包括蒸馏温度、蒸馏时间等。以柑桔皮渣压榨液为原料,研究确定了水蒸汽蒸馏提取苧烯的适宜蒸馏温度为110℃、蒸馏时间为45min,其苧烯的浓度达到了90.38%。3.研究了苧烯的纯化技术。以减压蒸馏所得苧烯为原料,通过加入氧化剂、酸洗和水洗后,得到了纯度为98.2%的苧烯。其最适宜的工艺组合为:氧化剂为3%次氯酸钠,酸为2%磷酸。4.研究了超临界CO₂萃取苧烯的技术。研究了影响超临界CO₂萃取技术对苧烯提取效果的相关因素,包括萃取温度和萃取时间等。通过单因素实验,确定了萃取温度为55-60℃,萃取压力为8MPa-10MPa时能最大限度地将苧烯提取出来。影响超临界CO₂精馏萃取技术对苧烯提取效果的相关因素,包括萃取压力、萃取时间、萃取温度、温度梯度等,以橙油为原料,通过正交实验,确定了超临界CO₂精馏萃取苧烯的适宜工艺参数。以苧烯萃取率为判定指标时,其最适宜工艺组合为:萃取压力为8MPa,萃取温度为60℃,萃取时间为80min,温度梯度为40℃-55℃-60℃-65℃,萃取率达到94.16%;以苧烯浓度为判定指标时,其最适宜工艺组合为:萃取压力为8MPa,萃取温度为55℃,萃取时间为80min,温度梯度为40℃-55℃-60℃-65℃,苧烯浓度达到975.7μl/mL。更多还原

【Abstract】 D-limonene is a member of cyclohexanoid monoterpenes,which is especially found in citrus,vegetables and spices.It has great development-perspectives for its anti-cancer,antibacterial and other physiological functions,is widely used as flavour and fragrance additive in food and perfume industry,and also used in pharmaceutical industry for its physiological function.The thesis is about the extraction and purification of d-limonene aming at acquiring d-limonene product with high-content limonene. Taking citrus essential oil and citrus peel residues as raw materials,the vacuum distillation extraction,water steam distillation,Supercritical Fluid Extraction-CO₂ and chemical purification were used;and also the content of d-limonene in different citrus varieties juices and peels,concentration juices and fresh orange juices were determined and analyzed,and the statistic datas of d-limonene content in Citrus fruits were obtained.For getting safty and highly purified limonene product,the various procedure effects on the extraction and purification were studied and the best procedure parameters were acquired.The results is:1.The d-limonene content in juices and peels of 90 different citrus varieties is analyzed by distillation titration.The results showed that different citrus juices have different limonene content.The d-limonene content in Sweet orange,Tangerine,Tangor and grapefruit juices is obviously different,whose average levels is 0.0824‰、0.2785‰、0.1063‰、0.0450‰respectively.In our experiments the d-limonene content of 9 concentrated juices and 15 fresh juices from company also had been studied,the results showed that concentrated juices have a very low limonene levels,the average content is 0.0018‰;and the average content of fresh juices is 0.1125‰.The d-limonene content in Sweet orange,Tangerine,Tangor and grapefruit peels is obviously different,whose average levels is 4.527g/kg,2.115g/kg,4.994g/kg respectively.It is found that after storage the limonene content in citrus juice and peels all decreased,and as well as found in different varieties of citrus from different harvest-period. 2.The differences of two extraction methods were studied,The parameters having effect on vacuum distillation extraction for food-grade limonene include vacuum, distillation time,distillation temperature.Take the cold-pressed orange oil as raw material,by orthogonalexperiment,the optimistic combination is:vacuum 0.08MPa, distillation time 10min,liquidte-mperature170℃.The concentration of limonene reached 95%.At the meantime,also the steadistillation technology for technology-grade limonene was studied,the parameters aredistillation temperature,distillation time. Taking Citrus Peels slurry as raw material,byorthogonal experiment,the optimistic combination is:distillation temperature 110℃,distillation time 45min.The concentration of limonene reached 95.46%.3.Taking food-grade Limonene as raw materials,the purification technology was studied.The 98.2%limonene was obtained by a process including the step of mixing d-Limonene with an oxidizer and separating the oxidizer from the d-Limonene,and then mixed with an acid and separated and finally with a wash water step.The optimistic combination:3%sodium hlorite- oxidants and 2%phosphoric acid.The concentration of limonene reached 90.38%.4.Supercritical Fluid Extraction-CO₂ technology was studied.The parameters having effect on d-Limonene extraction include extraction-temperature and extraction-time.By single factor experiments,it was found that the maximum d-Limonene will be extracted under the extraction temperature 55-60℃and the extraction pressure 8-10MPa.The parameters having effect on d-Limonene extraction by supercritical fluid extraction-fractionation include the extraction-pressure,extraction -time,extraction-temperature and temperature gradient.Taking citrus oil as raw material,by the orthogonal experiment,regarding the extraction rate as the index,the optimistic combination is:extraction pressure 8MPa,extraction temperature 60℃, extraction time 80min,the temperature gradient 40℃-55℃-60℃-65℃.The extraction rate reached 94.16%;regarding the content of limonene as the index,the appropriate combination is:extraction pressure 8MPa,extraction temperature 55℃,extraction time 80min,temperature gradient 40℃-55℃-60℃-65℃.The concentration reached 975.7μl/ mL.更多还原