【作者】 张静；

【导师】 樊婷婷； 李玉；

【作者基本信息】 合肥工业大学 ， 食品工程（专业学位）， 2022， 硕士

【摘要】 草莓果实因富含各种营养成分且酸甜可口,故成为最受欢迎的水果之一。但草莓果实的果皮薄,容易损伤和病原菌感染,采摘后很快就腐烂了。传统上,化学试剂用于果蔬的保鲜,但如果控制不好其用量会导致化学试剂残留在果蔬表面,可能会对环境和人体健康带来潜在危害。因此,需要找到一种天然的生物活性物质来更好的保持草莓果实的营养品质。本文主要是从品质、抗氧化活性、活性氧（ROS）代谢和抗病机理这几个方面探索了白藜芦醇（Res）处理对采后草莓果实的保鲜效果。主要的结果如下:1.Res处理对采后草莓果实品质的影响。在4℃和25℃贮藏条件下,不同浓度的Res处理可以延长草莓果实的贮藏期,并且能够不同程度的延缓草莓果实的腐烂、水分流失和可溶性固形物（TSS）含量的下降。同时,100μM和200μM Res处理能够不同程度延缓草莓果实的硬度和总糖含量的下降。100μM Res处理能够保持草莓果实较高的维生素C（Vc）含量。另外,不同浓度的Res处理对草莓果实的果皮颜色、p H值和可滴定酸（TA）均没有显著的影响。上述结果说明不同浓度的Res处理能够保持草莓果实较好的营养品质,延长其货架期。2.Res处理对采后草莓果实抗氧化活性的影响。4℃贮藏条件下,与对照组相比,100μM和200μM Res处理能够保持草莓果实中较高的总酚、总黄酮和花青素含量。同时,采后草莓果实用100μM和200μM Res处理后,可以保持其较高的1,1-二苯基-2-三硝基苯肼（DPPH）、2,2’-联氮-双-3-乙基苯并噻唑啉-6-磺酸（ABTS）和羟基（·OH）自由基清除能力以及还原力。总之,Res处理可以保持草莓果实较高的抗氧化能力,从而保持草莓果实良好的品质。3.Res处理对采后草莓果实ROS代谢的影响。100μM和200μM Res处理能够抑制过氧化氢（H₂O₂）、超氧阴离子(O₂^·-)和丙二醛（MDA）在草莓果实中的积累。同时,100μM Res处理能够促进草莓果实中编码抗氧化酶相关基因（Fa Fe SOD1、Fa Fe SOD2、Fa CAT和Fa APX）表达,从而能够保持其较高的超氧化物歧化酶（SOD）,过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）活性。综上所述,Res处理通过调控ROS代谢途径来延缓草莓果实的衰老进程。4.Res处理对采后草莓果实抗病机理的研究。4℃贮藏条件下,100μM和200μM Res处理能够抑制草莓果实病斑直径和发病率的发生,并且能够保持草莓果实较高的酪氨酸解氨酶（TAL）、苯丙氨酸解氨酶（PAL）、过氧化氢酶（POD）、β-1,3-葡聚糖酶（β-1,3-GA）和几丁质酶活性。同时,100μM和200μM Res处理能够促进草莓果实中抗病相关基因表达。总之,Res处理能够有效的抑制草莓果实青霉病的发生,减少其腐烂,延长其货架期。更多还原

【Abstract】 The strawberry fruit is one of the most popular fruits because it is rich in various nutrients and tastes sour,sweet and delicious.But the peel of strawberry fruit is thin,so the fruit is damaged and infected by pathogenic bacteria,and quickly decay after harvesting.Traditionally,chemical reagents are used for the preservation of fruits and vegetables,but if the dosage is not well controlled,it will cause chemical reagents to remain on the surface of fruits and vegetables,which may bring potential harm to the environment and human health.Therefore,it is necessary to find a natural bioactive substance to better maintain the nutritional quality of the strawberry fruit.In this paper,we explored the effects of resveratrol（Res）treatment on the preservation of postharvest strawberry fruit mainly from such aspects as quality,antioxidant activity,reactive oxygen species（ROS）metabolism,and disease resistance mechanism.The main results were as follows:1.Effects of Res treatment on postharvest strawberry fruit quality.Under the storage conditions of 4℃and 25℃,different concentrations of Res treatment could prolong the storage period of strawberry fruit,and delay the decay,water loss and the decrease of total soluble solid（TSS）content of strawberry fruit to different degrees.At the same time,100μM and 200μM Res treatment could delay the decrease of firmness and total sugar content of strawberry fruit to different degrees.100μM Res treatment could maintain the high content of vitamin C（VC）in strawberry fruit.In addition,different concentrations of Res had no significant effect on the peel color,p H value and titratable acidity（TA）of strawberry fruit.The above results indicated that different concentrations of Res treatment can maintain the better nutritional quality of strawberry fruit and prolong its shelf life.2.Effects of Res treatment on antioxidant activity of postharvest strawberry fruit.Under the storage condition of 4℃,100μM and 200μM Res treatment was able to maintain higher total phenolic,total flavonoid and anthocyanin contents in strawberry fruit compared to the control group.Meanwhile,the postharvest strawberry fruit treated with 100μM and 200μM Res could maintain higher 1,1-diphenyl-2-picrylhydrazyl（DPPH）,2,2’-azino-bis（3-ethylbenzothiazoline-6-sulfonic acid）（ABTS）and hydroxyl（·OH）radical scavenging capacities as well as reducing power.In conclusion,the Res treatment could maintain the higher antioxidant capacity of strawberry fruit and thus maintain the good quality of strawberry fruit.3.Effects of Res treatment on ROS metabolism of postharvest strawberry fruit.100μM and 200μM Res treatment could inhibit the accumulation of hydrogen peroxide（H₂O₂）,superoxide anion(O₂^·-)and malondialdehyde（MDA）in strawberry fruit.Meanwhile,100μM Res treatment could promote the expression of genes encoding antioxidant enzymes（Fa Fe SOD1,Fa Fe SOD2,Fa CAT and Fa APX）in strawberry fruit,so as to maintain its high activities of superoxide dismutase（SOD）,catalase（CAT）and ascorbic acid peroxidase（APX）.In conclusion,Res treatment can delay the aging process of strawberry fruit by regulating ROS metabolism pathway.4.Study on the mechanism of disease resistance of postharvest strawberry fruit by Res treatment.Under the storage condition of 4℃,100μM and 200μM Res treatment inhibited strawberry fruit lesion diameter and decay incidence,and maintained high tyrosine ammonia-lyase（TAL）,phenylalanine ammonia-lyase（PAL）,catalase（POD）,β-1,3-glucanase（β-1,3-GA）and chitinase activity.Meanwhile,100μM and 200μM Res treatment could promote the expression of disease resistance-related genes in strawberry fruit.In conclusion,Res treatment can effectively inhibit the occurrence of penicillium disease of strawberry fruit,reduce its decay and prolong its shelf life.更多还原