【作者】 唐长波；

【导师】 岳田利；

【作者基本信息】 西北农林科技大学 ， 食品科学， 2007， 硕士

【摘要】 富马酸是浓缩苹果汁的品质检测项目之一,在实际生产中时常超标,使得我国苹果浓缩汁的国际竞争力严重下降,给果汁生产企业造成了一定的经济损失,成为浓缩苹果汁安全性控制的重要指标。论文以系统研究了大孔树脂吸附和固相萃取对富马酸的吸附、洗脱和再生的工艺条件,建立了苹果汁中富马酸的富集方法;再结合近红外光谱法,实现了苹果汁中富马酸的快速检测。论文取得的主要研究结果如下:1.研究了多种大孔吸附树脂对富马酸的吸附与脱附性能,从中选出D-296R树脂具有较大吸附量和解吸率。通过动态吸附试验,研究了温度、pH、浓度、流速对D-296R树脂吸附量的影响,以水为溶媒,富马酸吸附量为考察指标,采用L₉ （3）⁴正交试验法对富马酸吸附工艺进行优选了优选:上柱液的温度30℃, pH3.0,浓度1 mg/ml,流速1 BV/h;并从淋洗液和洗脱液两方面对解吸工艺进行了研究,结果表明:用2倍树脂体积的蒸馏水为淋洗剂,用80%的乙醇以1BV/h的流速进行洗脱,效果甚佳。2.通过对固相萃取的主要影响因素进行研究,确定了最佳条件:用0.1 M氢氧化钠溶液调节果汁pH值至7.0,用4 ml的0.1 M氢氧化钠活化柱子,取25ml的果汁上样,再用4 ml去蒸馏水淋洗柱子,最后用1.5ml 0.1 M的硫酸溶液洗脱富马酸,将洗脱液通过液相色谱检测,果汁样品中富马酸的回收率为60.8 - 79.4%.3.应用傅立叶变换近红外光谱法测定40个果汁的近红外光谱数据,用OPUS/QUANT5.5定量分析软件将光谱与对应的化学成分值相关联,建立了果汁中富马酸的回归模型。富马酸含量近红外光谱分析模型的决定系数R²为97.53,交叉验证均方根RMSECV为0.00416。用该模型对10个未知样品进行了外部验证,外部验证的决定系数（R²）为99.1 ,均方差（RMSEP）为0.00294。内部交叉验证和外部验证均证明,近红外定量分析有较高的准确度,能够应用于生产领域。更多还原

【Abstract】 The process conditions of extracting fumaric acid from apple juice concentrated with macro porous resin and ion change cartridge is studied; then we establish a mathematical prediction model of fumaric acid extracted with FT - NIR spectrometry for rapid determination. The main contributions of this thesis are as follows:The properties of static and dynamic adsorption and desorption of macro porous resin for fumaric acid were investigated. The D-296R resin was selected to purify fumaric acid. The effects of concentration, pH and work speed of the infusion on the adsorption of the D-296R resin were studied with static experiment. An orthogonal design was used for adsorption technology: the temperature is 30℃,the pH is 3.0,the concentration is 1 mg/ml,the flow velocity is 1 BV/h。;Desorption technology of studied with : The distilled water with 8 volumes of macro porous resin is used for washing impurity, 80% alcohol with the flow velocity of 1BV/h for washing fumaric acid out.The different parameters which affected the extraction procedure were studied and optimized to establish the optimal conditions for maximum recovery of fumaric acid and minimum extraction of interferences. The optimized procedure used a cartridge which was activated with 4 ml of 0.1 M sodium hydroxide solution. A 25 ml volume of apple juice solution (pH=7.0) was passed at a flow-rate. The cartridge was washed with 4 ml of water and fumaric acid was eluted with 1.5 ml of 0.1 M sulfuric acid. This solution was injected directly into the chromatograph. The recovery of juice sample was satisfactory and ranged from 60.8 to 79.4%.Near infrared reflectance spectroscopy has advantages of rapid determination, non-destruction, non-polluting and low cost. In the work, a mathematical prediction model of fumaric acid in apple juice concentrated with FT - NIR spectrometry was established. The determination coefficient ( R~2) of the model was97.53 and its root mean square error(RMSE) was 0.00416 in cross validation , and the average relative standard deviation between predicted value and measured value is 8.65%. This method was simple, rapid and accurate , it could be used to determine fumaric acid in apple juice concentrated.更多还原