【作者】 魏军香；

【导师】 张跃进； 梁宗锁；

【作者基本信息】 西北农林科技大学 ， 中药学， 2012， 硕士

【摘要】 本论文以陕南略阳县雪莲果基地2010年和2011年大田栽培的雪莲果为试验材料来源，从每年8月初开始每隔15天赴基地采挖一次雪莲果块根，直到11月中下旬进入冬季，雪莲果植株地上部分开始枯萎，雪莲果大收获为止。不同采收时间带回的块根在实验室经过去皮灭酶处理，烘干粉碎供做采收样品粉末；同时，选取2010年大收获时的块根作为储藏试验材料，将其随即装箱分为2组，一组储藏于常温实验室下，令一组储藏在4℃冷库中，对每组储存箱内雪莲果标记称重。从采收之日作为储藏0天，以后每隔20天按顺序分别取常温和冷藏块根样品，共进行7次即从储藏开始到储藏145天，采用同采收一样的处理方法，获得储藏样品粉末。测定采收各个时期样品粉末中低聚果糖（FOS）、总糖、总酚酸、绿原酸、总黄酮和粗蛋白的含量，分析其含量变化并绘制各个成分动态积累曲线，结合产量因素确定最佳采收时间；用同样方法测定储藏样品粉末中以上各成分，分析比较各种成分在2中储藏条件下随着储藏时间延长的含量变化并绘制动态变化曲线，根据利用目的不同选取适宜的储藏条件和储藏天数。通过以上研究为略阳雪莲果采收期的确定和储藏方式提供科学依据和参考，指导当地实际生产。另外，以基地产雪莲果块根为原材料，在实验室条件下试制雪莲果果脯和果汁产品，果脯考察护色剂和糖液组成对果脯品质影响，果汁考察护色剂、澄清剂、稳定剂和灭菌方法对果汁品质影响，以评分结果作为指标，选择适宜加工方法和工艺流程，为雪莲果产品开发提供指导。1.采收试验中用微波提取法提取样品中营养型物质FOS和总糖，采用分光光度法测定含量，结果表明低聚果糖和总糖的变化情况较为相似，都是在前期快速积累，到10月末11月后2次采收时，含量较为稳定，总糖含量达到干基76%，低聚果糖含量最大为干基的52%；块根中另一种考察的营养型成分粗蛋白含量变化为生长期中间10月中旬有下降，但总体变化幅度不大，到最后一次11月中下旬采收时含量达到4.28%；利用超声波提取法提取块根酚酸类物质包括绿原酸，用分光光度法和高效液相色谱法分别测定，结果显示总酚酸和绿原酸在整个生长期内的积累也是逐渐上升到后2次即10月末11月上旬时稳定并达到最大，分别为达到3.8mg·g^-1和0.35mg·g^-1；另外一种与雪莲果药理作用密切相关的物质总黄酮含量的变化较为特殊，10月中旬便达到最大9.75mg·g^-1，到最后一次采收时稍微有下降到8.05mg·g^-1，由于叶中黄酮含量和叶中相比较低，所以单独利用块根中黄酮的意义不大。综上所述，结合雪莲果块根鲜重和折干率，综合考察各营养型成分和药理功效成分，略阳雪莲果应从11月中旬开始采收，这与当地的在霜冻来临之前采收的说法一致。2.储藏试验样品中营养型成分和药理功效成分的提取方法和测定方法分别同采收试验一样。结果表明，两种储藏条件下，营养型成分的低聚果糖含量动态变化规律相似，但同一储藏天数含量各不同，在整个储藏期内，4℃低温储藏块根中FOS含量均高于常温组，且FOS的分解总是较常温组迟，也就是保存较长时间不分解为小分子单糖；两种储藏条件下总糖含量在整个储藏期内变化不大，所以，以雪莲果中低聚果糖为主要获取目标使用或加工时，以新鲜采收的或4℃低温储藏20d以内或储藏85d¹25d之内的为佳；若以生食雪莲果以甜度考虑的则在雪莲果块根外形变化不大、失水不严重前天下，选用常温储藏45d左右或低温125d以后的，但常温相较低温成本低，所以更为宜。块根中具药理功能的总酚酸常温组含量明显小于低温组各储藏时期，低温组在储藏45d和105d¹25d内含量较高，因此以总酚酸为利用目标的应选取4℃低温储藏且在45d左右和105d¹25d内；总黄酮含量变化不大且储藏条件对其影响也小，所以以块根中具有药理功效成分为目标的，结合储藏过程中块根重量损失情况，最好选用的是低温储藏45d左右或125d左右的为佳。3.产品试制结果表明，以1.5%食盐+0.5%柠檬酸+0.5%氯化钙+0.15%抗坏血酸的组合护色硬化剂和25%白砂糖+15%葡萄糖+0.1%羧甲基纤维素钠+0.2%柠檬酸的甜型糖液组合经过超声波渗糖和自然浸糖所制的的果脯没有发生褐变，色泽、软硬度、口感、酸甜度和外观良好；雪莲果果汁试制所用的0.10%抗坏血酸+0.10%柠檬酸+.0.10%NaSO₃+1.5%氯化钠组合护色剂和巴氏灭菌法都最大程度保留了雪莲果原汁的风味营养价值和雪莲果的清香味，在保存过程未出现褐变和沉淀，说明果汁选用的热烫方法、护色剂、稳定剂和灭菌方法可行可靠。总之，上述使用的加工试剂和工艺流程简单可行，操作简便，成本低，对当地小规模生产具有一定指导意义。更多还原

【Abstract】 With field cultivated yacon tuber in year2010and2011in Lueyang base of south Shaanxias this experimental materials, the method of obtaining was been to yacon base and scoop theunderground tubers every fifteen days since the beginning of August of each year until the end ofNovember when the winter was coming and the aboveground part of yacon plants were startingto wilt. The tubers of different harvest time should be peeled and deactivated enzyme every timewhen they are brought back from the base, and then drying and crushing as the harvest samples.meanwhile, selected the tubers of the final harvest of year2010as the storage experimentalmaterial and divided into two groups at random, with one stored under room condition and theother in4℃after the tubers in each group was marked and weighed; the day of final harvest isthe first day of storage and then took out the sample in orders of both storage condition everytwenty days afterwards. This step was going on seven times and that means the whole storageperiod was145days. The processing method of storage material is the same as harvestexperiment. The harvest sample and storage sample were ready to under analysis respectively.Doing determination of the main ingredients including fructooligosaccharide （FOS）, totalsugar, phenolic acids, chlorogenic acid, total flavonoids and proteins, and analysed thefluctuation and draw the curve of dynamic change of each component’s content, and according tothe output and then ascertain the best harvest time. The same determination method could applyto the storage sample. Doing analytical research on the content change of each component andcompare them under two different storage conditions and times, then draw the dynamic changecurve, selecting optimal storage condition and time according to various aims and usage. Theresults of above researches can provide scientific suggestion and reference of harvest time andway of storage for yacon in Lueyang region and offer practical guidance for them. Furthermore,using the tuber of Lueyang yacon as raw material, made yacon preserved fruit and yacon juice inLab. Investigate the impact of antibrowing agent and sugar solution constitute on yaconpreserved fruit as well as antibrowning, clarifying and sterilization method on yacon juice, whichcan provide guidance for the yacon product development.1. In harvest experiment, FOS and total sugar were extracted by microwave method, and its contents were measured by Uv-vis method. The results showed that fluctuation of FOS and totalsugar contents are similar. Both of them accumulated quickly at the first harvest stage and didn’tstay stable until beginning of November. The conten of FOS and total sugar were76%（DW） and52%（DW） at that time respectively; The content of total protein, another nutritional componentin yacon tuber, was4.28%at end of November with a drop at middle of October but didn’tobvious. The phenolic acids including chlorogenic acid were extracted by ultrasonic method, andmeasured by Uv-vis and HPLC respectively. The results indicated that the phenolic acids andchlorogenic acid accumulated and ascended gradually during entire growth period and staystable at last two harvest times, namely, the beginning of November, which content were3.8mg·g^-1and0.35mg·g^-1respectively; Flavonoids, another pharmacological component inyacon tuber, was a little bit special, which reached its maximum at middle of October and had aslight descent at the last harvest, the content is9.75mg·g^-1and8.05mg·g^-1respectively. In sum,combined with the consideration of yacon tuber’s fresh weight, drying rate and the contents ofvarious nutritional and pharmacological components, the best harvest time should start at themiddle of November. This conclusion is the same with the local opinion: yacon tuber should beharvested before the frost.2. Extraction and measurement methods of both nutritional and pharmacological componentfor storage experiment were the same as harvest experiment. The results argued that the dynamicchange of FOS are similar under two storage conditions while the content are dissimilar duringsame storage days. In the whole storage period, the FOS content of4℃were always higher thanits counterpart and the drop much later, that is to say, FOS in4℃group could stay for a longtime rather than decomposed into sucrose and monosaccharide. The fluctuation of total sugarcontent was tiny during the entire storage period, therefore, when the FOS is the main acquiredtarget, it is better the store in4℃for20days or between85to125days; On contrast, if yacon isfor raw food and sweetness is into consideration, it should better store in4℃after125days orin room condition for45day on condition that the weight loss was low, but the room condition iscosteffective, so it is more available. The content of phenolic acid in room condition were lowerthan4℃at every storage time and reached its highest when stored in4℃for45days andbetween105to125days, so it should be took out at this time when you want to get morephenolic acids. The fluctuation of total flavonoids was unconspicuous under two conditions, so itis better stored in4℃for45or125days when you want get more pharmacological compound.3. The result of trial production indicated that the yacon preserved fruit, after processed bythe antibrowning agent which consist of1.5%sodium chloride,0.5%citric acid,0.5%calciumchloride and0.15%ascorbic acid as well as sugar solution which consist of25%sucrose,15% glucose,0.1%CMC-Na2and0.2%citric acid, were not browning and had better mouthfeel andgood appearance. The antibrowning agent consist of0.1%ascorbic acid,0.1%citric acid,0.1%sodium sulfite and1.5%sodium chloride as well as pasteurization for processing of yacon juicehad preserved the flavor and nutrition value of yacon, what is more, yacon juice did notbrowning and appear precipitation for a long time, so all the agent and methods were proved tobe feasible.更多还原