【作者】 刘杰超；

【导师】 王思新；

【作者基本信息】 中国农业科学院 ， 农产品加工及贮藏工程， 2003， 硕士

【摘要】 本文首先以秦冠、富士、嘎拉、华冠、华帅、金冠、国光、首红、澳洲青苹等9个品种为试材，对苹果果实发育过程中总酚、绿原酸、黄烷醇、原花色素含量进行了分析，并通过对树脂的筛选和吸附及解吸条件的优化，结合苹果浓缩汁加工工艺提出了树脂法分离提取苹果汁中多酚物质的工艺路线，最后对按照提出的工艺所制备的苹果多酚提取物的生物活性进行了研究，以期为苹果加工原料的选择和工艺技术的改进及苹果多酚的开发利用提供基础资料和参考依据。 结果表明： 苹果果肉中多酚物质的含量和组成在不同品种间存在着较大差异；总酚、绿原酸、黄烷醇和原花色素含量在苹果发育初期迅速下降，其后下降速度逐渐减缓，最后则趋于稳定或稍有下降。从多酚物质含量方面考虑，澳洲青苹为加工苹果汁比较适宜的原料品种，幼果是提取多酚物质的最佳原料。 XDA-5树脂是吸附分离苹果汁中多酚物质的优良材料，其吸附最适温度为40℃，适宜洗脱溶剂为80％乙醇溶液。从苹果汁中分离提取多酚物质的最佳工艺路线为：苹果在破碎时加入防护剂，并在榨汁后立即进行灭酶处理；然后果汁再经过酶解、澄清、超过滤等工艺后，对澄清的果汁进行XDA-5树脂吸附（40℃）处理，所得清汁经浓缩、杀菌、灌装后成为苹果浓缩汁产品，而树脂吸附量达到一定程度后用80％的乙醇溶液洗脱，洗脱液经真空浓缩后进行喷雾干燥或真空干燥得到苹果多酚提取物。本工艺既能提高苹果浓缩汁的品质，又实现了资源的充分利用。根据该工艺制备的苹果多酚提取物中总酚含量可达到96.72％，其中各类多酚物质的含量分别为绿原酸20.76％，黄烷醇70.58％（其中原花色素占88.21％）。 按照以上工艺制备的苹果多酚提取物具有较强的还原能力和抗脂质过氧化活性，并对羟自山基、超氧阴离子自由基及亚硝基具有很强的清除作用，且优于同浓度的维生素C。在试验浓度范围内，其对亚油酸自氧化、NO₂^-、Fenton反应产生的羟自由基及光照核黄素和邻苯三酚自氧化产生的O（?）的最大清除率或抑制率分别可达到94.4％、95.76％、96.64％、95.19％和90.48％。这说明该提取物是一种优良的天然抗氧化剂和自山基及NO₂^-清除剂，同时也证明本文提出的工艺能够较好地保持苹果多酚的生物活性。更多还原

【Abstract】 In this dissertation, the contents of total phenolics, chlorogenic acid, flavanols and proanthocyanidins in nine apple varieties, including Qinguan, Fuji, Gala, Huaguan, Huashuai, Golden Deliciou, Rails, Redchief Delicious and Granny Smith, were determined during development of fruits firstly. The process for extracting polyphenol compounds from apple juice was designed by resin screening and optimizing the condition of absorption and desoption. Finnaly, the bioactivities of apple polyphenol extracts made according to the process were studied.The results pointed to great quantitative differences in polyphenols composition and contents in the flesh of various apple varieties. The contents of total phenolics, chlorogenic acid, flavanols and proanthocyanidins in apple fruits fell sharply during early stage of development, and then decreased slightly or inclined to constant. It was suggested that Granny Smith was a better variety for production of apple juice and immature fruit was the best for extraction of polyphenol compounds according to the polyphenol content.XDA-5 resin was exellent for extraction of polyphenol compounds from apple juice, and the optimum absorption temprature was 40 C, 80% ethnol solution was better for desorption. The optimal process for extracting polyphenol compounds from apple juice was: Apples were crashed with repellent, and the juice were heated to inactive PPO after pressing immediatelly; Clarified juice obtained following enzyme treatment, clarification and ultrafilatration were adsorbed with XDA-5 resins; Resins were desorped with 80% ethnol solution, and apple polyphenol extratcts were obtained by concentrating and drying the washing-out solution at hypobaric conditions. This process not only can improve the quality of apple juice concentrate, but also utilize the resources sufficiently. The total phenol content of apple polyphenol extracts made according to the process came to 96.72%, the content of chlorogenic acid, flavanols and proanthocyanidins was 20.76%, 70.58% and 62.26% respectively.The apple polyphenol extracts had stronger reducing capacity, antioxidant activity on lipid-peroxidation, and scavenging effects on hydroxyl radical, superoxide anion radical and nitroso than ascorbic acid at the same concentration. In the range of test concentration, the maximum scavenging or inhibition rate of apple polyphenol extracts to linoleic acid auto-oxidation, nitroso, hydroxyl radical generated by Fenton reaction, superoxide anion radical generated by illuminating riboflavin and pyrogallol auto-oxidation was 94.4%, 95.76%, 96.64%, 95.19% and 90.48% respectively. The results suggested that the apple polyphenol extracts was an excellent natural antioxidants, free radical and nitroso scavenger. And they also proved that the process designed in this dissertation could maintain the bioactivities of apple polyphenols.更多还原