【作者】 谢永娟；

【导师】 童军茂；

【作者基本信息】 石河子大学 ， 农产品加工及贮藏工程， 2010， 硕士

【摘要】 新疆库尔勒香梨(Pyrus bretschneideri Rehd)为蔷薇科、梨属中的白梨品种,其种植历史已有1400--2000年。它以皮薄、肉脆、汁多、味甜等特点驰名中外。果胶物质是复杂的高分子化合物,可广泛的应用到食品、医药、工业等方面,可见其用途非常广泛[2]。对于果胶已有大量基础和应用研究工作,国内外主要从橘皮、西番莲果皮、柚皮、橙皮等中采用水和乙醇溶剂提取。目前,我国香梨的种植面积逐渐扩大、产量不断提高,但受到香梨产季集中和消费能力的限制,供大于求的矛盾相当突出,同时产生了大量的落果以及残次果[5],而在国内未对其进行果胶提取。如对此领域进行开发研究,将具有很深的开发潜力。本文以残次香梨为原料,通过对香梨中果胶的提取和含量测定,实现落果以及残次果再利用为目的,比较了传统酸萃取、微波辅助提取和超声波法提取三种方法对果胶得率的影响,采用活性炭对果胶提取液进行脱色；并研究了所提取香梨果胶的理化性质。研究所得结果表明：(1)采用单因素实验和正交实验设计法,得到传统酸水解提取果胶的最佳工艺参数为：提取温度90℃、提取时间pH为4.5、料液比1：20,果胶得率为4.79%；微波辅助提取果胶的最佳工艺参数为：微波炉功率400W,时间5mmin,pH为3.5,料液比1：9,果胶得率为4.89%；超声波提取果胶的最佳工艺参数为：pH为5、功率420W、时间45mmin、料液比1：25,果胶得率为2.21%。(2)香梨果胶液活性炭脱色的最佳工艺条件为：活性炭用量为1g/100m1、果胶液pH值为7、脱色温度为70℃、脱色时间为60 mmin,色素吸附率能达到78.5%。(3)本实验中还利用国标法测定香梨果胶的酯化度、干燥失重、灰分、半乳糖醛酸和pH等指标,均达到了我国的质量标准要求；另外,本论文分别对商品果胶与香梨果胶的溶解度、热稳定性和凝胶性等理化性质进行了比较分析。更多还原

【Abstract】 Xinjiang Korla Pear (Pyrus bretschneideri Rehd.) belongs to the Rosaceae, the white pear of Pyrus species. It has a cultivation history of about 1400-2000 years. It is well known for its thin, juicy and sweet both at home and abroad.Pectin is a complex polymer material and can be applied to a wide range of food, medicine, industry and so on. So its use can be seen at a very wide range. A large number of basic and applied research work have been made toward the pectin. They were extracted mainly from orange peel, passion fruit peel, naringin and hesperidin by using water and ethanol solvent from at home and abroad.At present, the planting area of pear is expanding gradually and the production is continued to increase in China. But the contradiction of supply exceeding demand is quite prominent because of constraints of the seasonal pear production and consumption capacity. At the same time, a large amount of droped fruit and the defective pears are produced[5,6],however, their pectins are not extracted at home. If this field can be researched and developed, profound potential for development will be produced.Used Pear as raw materials, this paper tries to achieve the re-using of droped fruit and defective fruit by the extraction and content determination of pectin in Pear, compares influences of three methods toward the content of fruit rubber, that is, the traditional acid extraction, microwave-assisted extraction and ultrasonic extraction, decolorats by the use of activated carbon, and finally ethanol precipitation method using high purity of pectin, and studied the physical and chemical properties of pectins in Pear. The results show that:(1) Optimization of single-factor experiments and orthogonal experimental design method are chosen. The best process parameters of traditional acid extraction of pectin is:extraction temperature 90℃, extraction time 80min, pH 4.5, solid liquid ratio 1:20, pectin yield is 4.79%; the best process parameters of microwave-assisted extraction of pectin is as follows:microwave power 400W, extraction time 5min, pH 3.5, solid liquid ratio 1:9, pectin yield is 4.89%; the best process parameters of ultrasonic extraction:pH 5, extraction power 420W, extraction time 45min, solid liquid ratio1:25 pectin yield is 2.21%.(2) Conclusion got by optimized single factor selecting experiment:active carbon dosage is 1g/100ml, pH is 7, temperature is 70, decolorization time for 60 min, pigment absorption rate of 78.5percent.(3) Degree of esterification, moisture, ash, pH, galacturonic acid content were determined by GB standard, and all the parameters of Korla Pear pectin was found to be in accord with the specification of GB. The solubility, hot-stability and gel properties were compared Korla Pear pectin with Commodities pectin. Key words:pear pectin; extraction; decolor; analysis of physical-chemical properitie and Application of pectin.更多还原