【作者】 张艳芬；

【导师】 郁志芳；

【作者基本信息】 南京农业大学 ， 食品工程， 2007， 硕士

【摘要】 新鲜荠菜去除根须、腐坏和黄叶片，按200g／袋装入塑料袋，并按挽口和敞口两种方式包装后置0℃环境贮藏，每处理重复三次。贮藏期间每3天测定荠菜组织的失重率、黄化率、超氧阴离子（O₂^-）和丙二醛（MDA）的含量、叶绿素含量和叶绿素酶活性、纤维素含量和纤维素酶活性，超氧化物歧化酶（SOD）、苯丙氨酸解氨酶（PAL）和过氧化物酶（POD）的活性，研究荠菜冷藏过程中品质和生理特性的变化，结果如下：1、0℃贮藏条件下，不论挽口还是敞口包装的新鲜荠菜前6天均未发生明显失重，6天后敞口包装荠菜重量损失随时间的延长迅速增加，贮藏12天后的荠菜失重率达到7.3％，显著高于相同条件下挽口包装荠菜2.0％的失重率。2、0℃冷藏条件下，新鲜荠菜黄化前6天相对较慢，以后随时间延长而迅速增加，贮藏结束时两种包装荠菜的黄化率均达到近30％。两种包装荠菜黄化速度的比较显示，贮藏前6天敞口包装荠菜黄化稍快，6天后挽口包装荠菜的黄化速度大于敞口包装的荠菜，并在9天后超过敞口包装的荠菜。3、0℃贮藏期间，挽口和敞口包装荠菜还原糖含量的变化不一致，前者持续缓慢下降；后者最初3天有明显下降，3～6天基本稳定，6天后出现增加直至贮藏结束。两种包装条件下的荠菜维生素C变化相似且没有明显差异，表现为前3天增加，3～6天下降，以后基本不变。低温贮藏期间，两种包装荠菜的叶绿素含量均有较大幅度的下降，但挽口包装荠菜的叶绿素损失少；纤维素含量逐步增加，至贮藏结束12天时比入贮时均增加了20％以上，且增加量以敞口包装为高。4、0℃贮藏条件下，挽口包装荠菜的呼吸要大于敞口包装荠菜，前者在前9天呼吸出现明显的上升，而后着总体呈现缓慢降低趋势。挽口包装荠菜叶片组织的电导率整个贮藏期间略有增加，而敞口包装荠菜的电导率贮藏前6天显著增加以后明显下降。挽口包装的荠菜的O₂和MDA含量的变化总体小于敞口包装荠菜，最大值也以敞口包装荠菜为高。5、0℃贮藏、挽口包装荠菜的叶绿素酶和纤维素酶变化幅度都不大，随贮藏时间延长增加的量小于敞口包装的荠菜；叶绿素酶活性呈先增长后下降趋势，纤维素酶先上升后呈下降趋势。低温贮藏期间荠菜超氧化物歧化酶（SOD）活性的变化呈下降趋势、过氧化物酶（POD）和苯丙氨酸解氨酶（PAL）活性呈上升趋势、PPO活性极弱且贮藏期间没有变化，两种包装方式间没有显著差异。6、新鲜荠菜组织中TP和FP含量分别为9.483和2.177ug.g^-1.FW，FP占TP的比例27.86％；贮藏期间两种包装方式荠菜组织中TP和FP含量均有所减少，且挽口包装总酚含量较低。荠菜组织中酚类物质的初步鉴定结果显示荠菜组织中的主要酚类物质是焦性没食子酸。7、荠菜在0℃和挽口的条件下，贮藏时间可达到12d以上。更多还原

【Abstract】 The fresh Capsella bursa-pastoris after removing roots, decay and yellow leaves werepacked in plastic bags either loosely closed or opened with each sample 200 grams, andthen stored at 0℃. The treatment was replicate for 3times. The weight loss, etiolation rate,contents of chlorophyll, cellulose, O₂^·-and MDA, activities of chlorophyllase, cellulase,SOD, POD and PAL were determined at the interval of 3 days to investigate the quality andphysiological characteristic change of Capsella bursa-pastoris during storage period. Theresults is showed as following:1. The weight loss of Capsella bursa-pastoris at 0℃, no matter loosely closed packedor openly packed, was all very small during first 6 days, and then the weight loss of openlypacked Capsella bursa-pastoris increased greatly with extending storage duration reached7.3% at the end storage of 12days, compared with only 2.0% weight loss in the looselyclosed packed Capsella bursa-pastoris.2. The etiolation rate of Capsella bursa-pastoris increased graduallyat the early stageof storage and increased sharply after 6 days during storage at 0℃. Both etiolation rate ofloosely closed packed and openly packed Capsella bursa-pastoris at the end of storage （12days） reached nearly 30%. Making comparison of etiolation rate of two type package,openly packed Capsella bursa-pastoris etiolated faster during first 6 days, while looselyclosed packed etiolated faster during second 6 days.3、Reducing sugar change of two type packed Capsella bursa-pastoris had differentpattern at 0℃storage period. Reducing sugar in loosely closed packed Capsellabursa-pastoris slowly decreased continously, while reducing sugar in openly packedCapsella bursa-pastoris redued at first 3 days, remained stable between 3 and 6 days, andthen increased until the end of storage. Vitamin C in both loosely closed packed andopenlypacked Capsella bursa-pastoris showed the same change trendency, i.e. increasing winthin3 days, decreasing between 3 and 6 days and then remainging stable, and there was nosignificant different between them. The chlorophyll content of both packed Capsellabursa-pastoris decreased significantly during storage at 0℃with a little less loss of chlorophyll in loosely closed packed Capsella bursa-pastoris. Compared to celluloseamount at the beginning of the storage, cellulose gradually increased up to more than 120%with more increase in opened packed Capsella bursa-pastoris.4. The respiratory rate of Capsella bursa-pastoris packed in loosely closed plastic bagsand stored at 0℃was increased dring first 9 days and then sharply decreased, while thatof Capsella bursa-pastoris packed openly in plastic bags and stored at 0℃was overallslightly decreased, therefore the loosely closed packed Capsella bursa-pastoris had agreater respiratory rate. The relative conductivity of loosely closed packed Capsellabursa-pastoris during storage at 0℃was stabe with a little increase, while the relativeconductivity of openly packed Capsella bursa-pastoris during storage at 0℃was increasedsignificantly in first 6 days and then decreased greatly. The both content of O₂ and MDAand maximum value in the tissue of Capsella bursa-pastoris packed in loosely closedplastic bags and stored at 0℃were smaller than that of Capsella bursa-pastoris packedopenly in plastic bags and stored at 0℃.5. The activities of chlorophyllase and cellulase in Capsella bursa-pastoris packed inloosely closed plastic bags and stored at 0℃were all changed not too much, and theactivity change was smaller than that of Capsella bursa-pastoris packed openly in plasticbags and stored at 0℃. The change of chlorophyllase and cellulase activities showed thesame tendency, which was increased first and then decreased. Capsella bursa-pastoris hadno PPO activity. During storage period at 0℃, SOD activity in Capsella bursa-pastoriswas slow down, while POD and PAL were slowly increased. The activity difference ofSOD, POD and PAL between two package types was not significant.6. The content of total phenols （TP） and free phenols （FP） in fresh Capsellabursa-pastoris was 9.483 and 2.177ug·g^-1FW, respectively, and the ratio of free phenols （FP）to total phenols （TP） was 27.86%. The main phenol in the tissue of bursa-pastoris wasPyrogallol Pyrogallic Acid.7. The storage duration of Capsella bursa-pastoris which was loosely packed andstored at 0℃could be as long as 12 days.更多还原