【作者】 赵丛枝；

【导师】 张子德； 马俊莲；

【作者基本信息】 河北农业大学 ， 农产品加工及贮藏工程， 2004， 硕士

【摘要】 赞皇大枣皮薄、肉厚，甘甜鲜美、营养丰富，食用价值和商品价值极高。赞皇大枣可用于鲜食或加工蜜枣、干枣，随着人们对鲜食枣果营养价值的认同，鲜枣作为一种新型水果已逐渐开始被消费者所接受，鲜食的赞皇大枣的消费量逐渐增加，市场前景也比较看好。但赞皇大枣采后在自然状态下极易失水皱缩、酒软或霉烂，并伴有大量的Vc损失，营养价值降低，鲜食品质逐渐丧失。 目前赞皇大枣的贮藏保鲜问题尚未解决，严重影响着赞皇大枣业的发展。本研究以赞皇县所产的赞皇大枣为试材，研究了赞皇大枣采后的贮藏生理特性、品质变化，以及不同温度、不同气体条件下赞皇大枣的贮藏效果，确定了赞皇大枣最佳的气调贮藏工艺。其主要研究结果如下： 1 赞皇大枣果实在整个贮藏期间无呼吸高峰出现，属非跃变型果实。 2 对不同处理赞皇大枣失重率的测定表明，PVC打孔袋包装、低温、适宜的低氧气体条件能够减少水分蒸腾，抑制呼吸作用，从而显著地降低赞皇大枣果实的失重速率。 3 赞皇大枣果实硬度随着贮藏期的延长而逐渐降低，气调贮藏对保持果实的硬度有很好的作用。 4 赞皇大枣在贮藏过程中Vc、可滴定酸含量逐渐降低，还原糖含量逐渐升高，总糖含量前期下降迅速，后期变化平缓，乙醇和MDA含量前期缓慢上升，后期上升加快，PG酶和淀粉酶活性逐渐降低。 5 PG酶和淀粉酶的活性与赞皇大枣果实硬度的保持均呈显著的负相关，相关系数分别为r=-0.981和r=-0.648。 6 赞皇大枣的冰点温度为-3.5℃。 7 果皮转红与枣果的软化次序相一致，果面全部转红后，果肉会迅速的软化褐变，果皮颜色的变化可指示果肉软化的程度。 8 全红果不耐贮藏，适宜采后立即销售或仅作短期贮藏；初红果和半红果耐贮性较好，但初红果采后失重率较高，不宜长期贮藏，半红果适宜作长期贮藏。 9 用作长期贮藏的鲜食赞皇大枣，采收时一定要用手采摘，而且要留有果柄，但是不要带叶采收，更不要带有枣吊。 10 采收后的枣果用1％的蜂胶处理后再进行贮藏，可以大大减少枣果的霉烂损失，延长果实的保鲜期，改善其外观，提高赞皇大枣的商品价值。 11 气调贮藏效果明显优于单纯的冷藏，赞皇大枣最佳的气调贮藏工艺为：赞皇大枣在半红期带果柄采收→及时运输并在0℃下预冷→分级，剔除机械伤、病虫害等不合格果实→防腐剂处理→用0.03mm厚的PVC打孔袋包装→在0℃，相对湿度90％～95％，O₂浓度2％～4％，CO₂浓度小于3％的条件下贮藏。在该条件下贮藏赞皇大枣80d，好果率达79.8％，可食率可达98.6％。更多还原

【Abstract】 Zanhuang Jujube, with thin peel and sweet crisp flesh, is affluent in nutrition. Its edible value and commercial value are very high. Zanhuang jujube can be used for the fresh food or process candied date and merchandise of dried fruits. With people to worth the nourishment valuer in fresh jujube, it’s consumption increased gradually, and the marketforeground is vast. But after harvest, Zanhuang jujube is inclined to lose water and crimpled, with softening, rotting and Vitamin C lose, the nutrition and the high quality is not maintained under condition of room temperature.At present, the problem of fresh-keeping for Zanhuang jujube is not resolved, which affects the development of Zanhuang jujube greatly. In this paper, changes in quality and physiology of fresh Zanhuang jujube were studied under different storage temperature and different atmosphere conditions, and the optimum storage technology of the jujube was developed. The main research results were as follow:1 The study on the respiration of Zanhuang jujube in the different temperatures showed that the respiration peak were not found during storage after harvest. It was belong to non-cKmacteric fruit.2 The weight-loss rate of Zanhuang jujube during storage was reduced markedly by the low temperature combining with the appropriate lowoxygen content storage and package of PVC film bag with holes.3 with the storage time, the firmness of Zanhuang jujube reduced gradually, C A had a good effect on keeping firmness. The condition that temperature of 0℃ and the oxygen content of 2%~4% had the best effect on inhibiting softening, and excellent quality of the fruit was maintained after 80 days storage.4 During storage, Vc and titratable acid content decreased constantly, reducing sugar content increased gradually, total sugar content increased rapidly in the earlier stage and slowly in the later time, ethanol and MDA content rose slowly in the earlier stage and rose rapidly in the later time. The activity of PG enzyme and the activity of amylase decreased constantly.5 The activity of PG enzyme and the activity of amylase was negatively correlated withthe firmness of Zanhuang jujube significantly, r=-0.98l and r==-0;648 respectively.6 Zanhuang jujube fruit’s freezing point is -3.5℃.7 The fruit peel was turned red in accordance with the Zanhuang jujube softening in proper orderly mutually. When the fruit was turned red, flesh of the fruits soften quickly. The changes of the fruit peel color could instruct the degree that flesh fruits softening.8 The study on store-resisting ability of Zanhuang jujube in different maturity stage showed that the whole-red Zanhuang jujube’s store-resisting was low, so it was apt to market immediately or to store for short time after harvest. The white-ripening fruit and half-red fruit’s store-resisting ability was high, but the white-ripening fruit was inclined to lose water; so it was not fit for storage, the half-red fruits was apt to store for a long time.9 The fresh fruits used to stored over a long period of time, must be picked by hand, and reserve the fruit’ s handle, but do not take the leaf, even do not take the branches of the tree.10 Treatment the fruits with Propolis content of 1%. before storage, can reducing the loss of the fruits, prolong the fresh fruit period, improving its external appearance, increasing the merchandise value of the fruits.11 Compared with cold storage, controlled atmosphere storage(CA) had significant effects on keeping the fruit quality and delaying the fruit senescence, and the best CA storage technology was that: harvesting half-red Zanhuang jujube fruits, and reserving the fruit s handle → cooling at 0℃ on time→ rating and picking out the unqualified fruits →treatment with Propolis → packaging the fruit with PVC film bag → storage at 0℃, relative humidity of 90%- 95%, O2 content of 2%~ 4% and CO2 content less than 3%, After 80days storage, the percent of good fruit and edible fruit of Zanhuang jujube under this condition was 79更多还原