【作者】 肖静；

【导师】 康学军；

【作者基本信息】 东南大学 ， 营养与食品卫生学， 2006， 硕士

【摘要】 洋葱是传统的药食两用植物,在保健和预防、治疗慢性疾病等方面具有多种功效。近年来,随着人们对自身保健意识的增强,日益强调食品原料及添加剂的天然性、功能性,使得人们更加关注洋葱的药食兼用特性。本实验的主要目的是从洋葱中提取洋葱油,对洋葱油的有效成分进行分析,并对洋葱油微胶囊的制备进行研究,以期能够对洋葱油的提取方法和利用有所突破。本实验的主要工作包括以下三个方面:3.建立了溶剂提取和固相萃取洋葱油的实验方法采用溶剂提取法提取洋葱油,应用正交实验设计,考察了洋葱粉碎程度、酶解条件、干燥条件、提取溶剂以及提取方法等实验条件对洋葱油得油率的影响,经实验摸索,最佳的提取条件为:将新鲜洋葱剥皮、去根、洗净、切块后加入适量重蒸水进行匀浆(11800r/min)。称取匀浆液200克, 37℃避光,超声酶解48小时,酶解后置于80℃烘箱干燥,干燥物经研钵研细后石油醚回流提取2.5小时,提取结束后,将提取液过滤,滤液经55℃旋转蒸发浓缩后即得。提取的洋葱油为橙黄色透明液体,得油率为2.12%。以聚苯乙烯纤维丝为固定相,乙醇为流动相,采用固相萃取法提取洋葱油,考察了洋葱浆液的Ph值、固相萃取柱的活化、固相萃取柱的柱容量以及洗脱液的体积等因素对萃取效果的影响,最佳的萃取条件为:将新鲜洋葱去皮、去根、洗净、切块后加入适量重蒸水进行匀浆(11800r/min)。称取匀浆液200克,37℃避光酶解48小时后,用双层纱布过滤后滤纸过滤,用5mol/L的氢氧化钠溶液将滤液的Ph值调节至Ph=8,备用。称取15mg PS纤维丝,均匀密实地装填于自制的固相萃取装置中。将100Ml样品注入活化后的固相萃取柱,利用抽真空的方法,使样品中的有效成分吸附在固定相上,然后用50Μl乙醇作为洗脱液将目标物洗脱下来并加以收集。分别采用氧化还原聚合法和原子转移自由基聚合法合成了硅胶-温度敏感水凝胶颗粒,采用红外光谱、接触角测定及扫描电镜技术对其精细结构进行了表征。以该颗粒为固定相,荧光素钠为被分离物质,考察了其分离性能,探讨了其作为色谱固定相的可能性。结果显示空白硅胶颗粒与载体-温度敏感水凝胶颗粒在低温和高温时对荧光素钠的分离有截然不同的色谱行为,说明以载体-温度更多还原

【Abstract】 Onion is a medical and edible plant. It is an important flavoring that commands universal application as seasonings and flavorings in the food industry with the development of snacks and prepared foods. Furthermore, onion is used in folk therapy because of its biologically active sulphur compounds. In recent years, the general public has exhibited increased awareness of health-promoting functional foods.The goal of this work was to determine the optimal conditions of extraction for producing oleoresin with the highest yield and the best quality. Essential analysis and microcapsule preparation were carried out in the paper to make some breakthrough on the exploitation and utilization of onion oleoresin.Several main parts of this paper were summarized as follows:3. Solvent extraction and solid phase extraction of onion oleoresin With the oil yield as the evaluation index, the technology of extracting of onion oleoresin was studied. The effects of crushing degree, enzyme digestion condition, drying condition, extracting solvent, extracting method were investigated. An appropriate procedure of extracting onion oleoresin was established. The oil yield was 2.12%.Solid phase extraction with polystyrene as stationary phase, ethanol as mobile phase was studied. The effects of onion serous Ph, activation and capacity of the extracting column, the volume of mobile phase were investigated.Silica gel-thermosensitive hydrogel particles have been prepared and its application on stationary phases in chromatography have been evaluated.2. Sulphur concentration of onion oleoresin was determined by titration. The volatile compounds of extracted onion oleoresin were separated by gas chromatograph. The extracts of solid phase extraction were estimated by gas chromatography-mass spectrometry (GC-MS).Sulphur content of onion oleoresin was quantitatively determined by titration with bromimetry.更多还原