热空气复合茉莉酸甲酯处理对杨梅果实采后腐烂和品质的影响

目的 分析热空气复合茉莉酸甲酯(methyl jasmonate, MeJA)处理对杨梅果实采后腐烂和品质的影响。方法 将“乌种”杨梅在48 °C下进行10 μmol/L MeJA的熏蒸处理, 随后在20 °C下贮藏3 d或者1 °C下贮藏5、10 d、15 d后再20 °C贮藏1 d以模拟货架条件, 贮藏期间或结束后测定果实发病率以及硬度、可滴定酸(titratable acid, TA)、可溶性固形物(Total Soluble Solid, TSS)、维生素C和总酚等品质指标。同时, 采用芽管离体培养法测定该复合处理对Verticicladiella abietina(杨梅轮帚霉)孢子萌发和菌丝生长的影响。结果 10 μmol/L MeJA处理对V. abietina孢子萌发无明显抑制作用, 但可显著抑制病原菌菌丝的生长; 48 °C热空气处理则可显著抑制病原菌孢子萌发和菌丝生长。单一热空气或茉莉酸甲酯处理均可抑制杨梅果实采后贮藏期间绿霉病发病率, 但两者复合处理较单一处理更为显著的抑制了杨梅果实病害发生, 且经复合处理的杨梅果实其硬度、TA、TSS、维生素C和总酚含量均显著高于单一处理果实。结论 热空气复合茉莉酸甲酯处理可通过抑制V. abietina的生长从而控制杨梅果实采后腐烂并同时延缓果实品质下降, 从而为该复合处理的实际应用提供理论依据。     

茉莉酸甲酯处理对不同成熟度草莓果实采后腐烂和品质的影响

用1 μmol/L的茉莉酸甲酯(MeJA)处理八成熟和全熟时采摘的"丰香"草莓果实24h,然后在20℃下贮藏.结果表明,MeJA处理可显著抑制八成熟草莓贮藏过程中果实腐烂发生,而对全熟草莓果实腐烂发生无显著影响.MeJA处理促进八成熟果实贮藏前期可溶性固形物(TSS)含量的增加和总酸含量(TA)的下降,并促进果实红色的发育.经MeJA处理的八成熟果实在贮藏后期,果实表面颜色、可溶性固形物和VC含量等品质指标都接近于全熟果实.因此,对于采后不能及时销售和需要长途运输的草莓果实,可于较低成熟度时采摘,并采用MeJA处理,这样既能有效降低果实腐烂,同时又可保持其商品价值.     

采后热处理对草莓果实货架品质的影响

在预实验基础上,采用热空气46℃-1h、48℃-30min,热水浸润44℃-20min、46℃-15min对采后新鲜草莓(品种:永丰)进行热处理。处理后的草莓置(1±0.5)℃条件下冷藏1d,(20±1)℃条件下3d,对果实的呼吸作用和品质进行检测,发现处理后果实的呼吸作用明显减弱,热处理能够有效地起到防腐抑菌的作用,热水浸润处理对于根霉生长繁殖的抑制作用明显。48℃热空气处理30min和44℃热水浸润20min的果实具有较好的货架品质。     

茉莉酸甲酯对草莓果实采后腐烂、苯丙烷类代谢及抗氧化活性的影响

为研究茉莉酸甲酯处理(Methyl jasmonate,MeJA)对草莓果实采后腐烂、苯丙烷类代谢及抗氧化活性的影响,将果实先于20℃下以10μmol/L MeJA熏蒸处理6h,然后转入(1±1)℃下贮藏12d,每隔3d测定果实腐烂率、苯丙烷类代谢相关酶苯丙氨酸解氨酶(PAL)、对香豆酰-CoA连接酶(4-CL)、肉桂酸羟化酶(C4H)和二氢黄酮醇还原酶(DFR)活性以及总酚、总花色苷和酚类和花色苷类单体物质含量,并且同时测定果实DPPH(1,1-diphenyl-2-picrylhydrazyl)自由基清除率和总还原力。结果显示,MeJA处理可显著抑制草莓果实贮藏期间腐烂率的上升;同时MeJA可诱导PAL、4-CL、C4H和DFR活性的上升,从而有效延缓了酚类和花色苷类物质含量的下降,提高了果实DPPH自由基清除率和总还原力,维持了果实的抗氧化活性。这些结果表明,MeJA处理在草莓果实保鲜中具有较好的应用前景。     

杨梅果实采后热空气处理条件的优化

采用响应曲面法研究了不同温度-时间组合的热空气处理对"乌种"杨梅果实采后贮藏品质的影响,并对热空气条件进行了优化。结果表明:当热处理温度为48.5℃,处理时间为173 min时,有最优贮藏保鲜效果:杨梅果实于1℃下贮藏7 d再转移至20℃下模拟货架期放置1 d后的腐烂指数为18.81%、硬度为3.31 N、Vc含量为5.25 mg/kg(鲜重)、固酸比为16.42。     

采后热空气处理对杨梅果实冷藏期间品质及生理的影响

研究了杨梅果实(Myrica rubra sieb.et Zucc.)在47℃-3 h与53℃-2.5 h条件下热空气处理对果实在1℃,16 d贮藏期间品质及生理的影响。研究表明,杨梅果实采后在47℃-3 h与53℃-2.5h条件下热空气处理对可溶性固形物、可滴定酸、总糖、还原糖含量影响不大,但可减少冷藏期间果实腐烂的发生,抑制贮藏后期果实呼吸速率的上升,抑制果实的MDA含量、相对电导率和腐烂指数的上升。相比于53℃-2.5 h的处理,47℃-3 h处理能保持较高杨梅果实Vc含量和果肉硬度,减少果实失重,在维持品质方面效果更好。总之,热空气处理能够维持杨梅果实的品质、延缓衰老,延长贮藏寿命。     

1-MCP处理对贮藏后草莓的货架期品质的影响

草莓采后分别用500nL/L和1000nL/L浓度的1-MCP处理,贮藏于-1℃条件下21d后,置于4℃条件下,研究其货架期内品质变化。结果表明,经1-MCP处理过的果实,失水率远远低于对照组,货架期保持腐烂率低于10%能达到3～4d,货架期8d时腐烂率比对照减少约一半。1-MCP处理增加了果实中蛋白质含量,提高了超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性。实验表明,1-MCP处理提高了草莓贮藏后货架期的品质。     

热空气复合茉莉酸甲酯处理对杨梅果实采后腐烂和品质的影响（英文）

目的分析热空气复合茉莉酸甲酯(methyl jasmonate,Me JA)处理对杨梅果实采后腐烂和品质的影响。方法将"乌种"杨梅在48°C下进行10μmol/L Me JA的熏蒸处理,随后在20°C下贮藏3 d或者1°C下贮藏5、10 d、15 d后再20°C贮藏1 d以模拟货架条件,贮藏期间或结束后测定果实发病率以及硬度、可滴定酸(titratable acid,TA)、可溶性固形物(Total Soluble Solid,TSS)、维生素C和总酚等品质指标。同时,采用芽管离体培养法测定该复合处理对Verticicladiella abietina(杨梅轮帚霉)孢子萌发和菌丝生长的影响。结果 10μmol/L Me JA处理对V.abietina孢子萌发无明显抑制作用,但可显著抑制病原菌菌丝的生长;48°C热空气处理则可显著抑制病原菌孢子萌发和菌丝生长。单一热空气或茉莉酸甲酯处理均可抑制杨梅果实采后贮藏期间绿霉病发病率,但两者复合处理较单一处理更为显著的抑制了杨梅果实病害发生,且经复合处理的杨梅果实其硬度、TA、TSS、维生素C和总酚含量均显著高于单一处理果实。结论热空气复合茉莉酸甲酯处理可通过抑制V.abietina的生长从而控制杨梅果实采后腐烂并同时延缓果实品质下降,从而为该复合处理的实际应用提供理论依据。     

热处理与贮藏温度对草莓果实保鲜效果的影响

以大棚新鲜草莓为实验材料,分别研究2种热处理方式(40℃热空气,15min和40℃无菌水,15min)以及不同贮藏温度(常温20℃和低温4℃)对草莓的腐烂率、失重率的影响。结果表明,热处理明显有利于草莓的保鲜,其中热空气处理优于热水处理,低温贮藏优于常温贮藏。基于这一结论后,又以相同的新鲜草莓为实验材料,研究3种不同温度(35、40、45℃)的热空气和不同时间(10、15、20min)处理对草莓色泽、气味、硬度、酸度、糖含量以及呼吸强度的影响。结果表明,热处理能明显影响草莓贮藏期的生理和品质,热处理可保持草莓贮藏过程中的色泽、气味、硬度,降低其呼吸强度,减少草莓果实中糖和酸的损失,延缓草莓衰老。其中以45℃热空气处理10min保鲜效果最好。     

热空气处理对草莓果实品质和抗氧化活性的影响

研究热空气处理（45 ℃,3.5 h）对草莓在20 ℃、4 d贮藏期间果实品质、抗氧化活性及相关基因表达的影响。结果表明,热空气处理可以显著抑制果实腐烂的发生,延缓果实硬度、总黄酮、总酚和VC含量的下降,抑制花青素的积累,保持较高的DPPH自由基清除能力和还原力。另外,热处理可显著促进果实中黄酮醇合酶、查耳酮合酶和苯丙氨酸解氨酶基因的表达,而抑制β-木糖苷酶和花青素合酶基因的表达。这些结果表明,热空气处理可以通过调控相关基因的表达,较好地保持果实的品质和抗氧化活性。     

Reducing Chilling Injury of Loquat Fruit by Combined Treatment with Hot Air and Methyl Jasmonate

The effects of a combined treatment of hot air (HA, 38 °C for 6 h) and methyl jasmonate (MeJA, 16 μmol L^?1) on chilling injury, fruit quality, and physiological changes in loquat fruit stored at 1 °C were investigated. The results showed that treatment with HA or MeJA alone both significantly alleviated chilling injury in loquat fruit compared with the control, while their combination had the lowest level of chilling injury symptoms and highest quality. The activities of antioxidant enzymes such as superoxide dismutase, ascorbate peroxidase, and catalase were enhanced by the combination of HA and MeJA. In addition, the combined treatment significantly inhibited the activities of phenylalanine ammonia-lyase, peroxidase, and polyphenol oxidase, which resulted in lower lignin content. Highest level of polygalacturonase activity and water-soluble pectin content and lowest level of protopectin content were also observed in the combined treatment. These results suggested that the enhanced chilling tolerance by combination of HA and MeJA treatment in loquat fruit was related to the induction of antioxidant enzymes and the inhibition of lignin biosynthesis. The combination of HA and MeJA treatment could be a useful technique to alleviate chilling injury and maintain quality of loquat fruit during cold storage.     

Control of anthracnose rot and quality deterioration in loquat fruit with methyl jasmonate

BACKGROUND: Loquat (Eriobotrya japonica Lindl.) fruit has a short shelf‐life, mainly due to fungal decay. Current control of postharvest disease of the fruit is mainly dependent on fungicides. However, because of the increasing consumer concern over food safety, there is an urgent need to search for effective alternatives to control disease. The objective of this work was to determine the efficacy of methyl jasmonate (MeJA) in controlling anthracnose rot caused by Colletotrichum acutatum and maintaining quality of loquat fruit. RESULTS: Loquat fruit were treated with 10 µmol L^?1 MeJA and wound inoculated with C. acutatum spore suspension of 1.0 × 10⁵ spores mL^?1 24 h after treatment, and then stored at 20 °C for 6 days. The percentage of infected wounds showing decay symptom was reduced from 54.4% to 16.7% and the lesion diameter was reduced from 7.26 mm to 4.00 mm by MeJA treatment on the 4th day after inoculation. MeJA treatment induced higher activities of two defense‐related enzymes—chitinase and β‐1,3‐glucanase—during 6 days storage. Meanwhile, the treatment inhibited increases in fruit firmness and internal browning index, and maintained higher extractable juice rate and total soluble solids and titratable acidity contents, thereby delaying the development of flesh leatheriness. CONCLUSION: MeJA treatment effectively inhibited anthracnose rot and maintained quality in loquat fruit. Inhibition of the disease was mainly because of resistance induced in loquat fruit by MeJA. A postharvest application of MeJA could be an alternative to chemical fungicides for control of postharvest disease in loquat fruit. Copyright © 2008 Society of Chemical Industry     

Enhancing disease resistance in peach fruit with methyl jasmonate

BACKGROUND: Peaches are susceptible to microbial decay during postharvest distribution at ambient temperature. To search for effective alternatives to currently used fungicides for disease control, in this study the effect of methyl jasmonate (MeJA) on disease resistance and fruit decay of peaches after harvest in response to pathogen attack was investigated. RESULTS: Freshly harvested peaches were treated with 1 µmol L^?1 MeJA vapour at 20 °C for 24 h. At 0, 12, 24 and 36 h after this treatment, both treated and untreated fruits were artificially wounded and inoculated with Penicillium expansum, Botrytis cinerea or Rhizopus stolonifer spore suspension (1 × 10⁵ spores mL^?1) and then incubated at 20 °C for 6 days. MeJA treatment significantly reduced the postharvest diseases. Incubation for 12 h was the optimal length of time after MeJA treatment, resulting in the lowest disease incidence and lesion diameter for all pathogens. The activities of defence enzymes including chitinase, β‐1,3‐glucanase, phenylalanine ammonia‐lyase, polyphenol oxidase and peroxidase were enhanced by MeJA treatment, and the level of total phenolics in MeJA‐treated fruit was also higher than that in control fruit. In addition, MeJA affected hydrogen peroxide (H₂O₂)‐metabolising enzymes such as superoxide dismutase, catalase and ascorbate peroxidase and induced a higher level of H₂O₂ during incubation, which might serve as a signal to induce resistance against P. expansum. CONCLUSION: MeJA was effective in reducing decay and might enhance disease resistance in peach fruit by increasing levels of antipathogenic proteins and antimicrobial phenolic compounds. Copyright © 2009 Society of Chemical Industry     

采后热空气处理对枇杷果实抗病性的诱导

研究热空气处理对枇杷果实腐烂和抗病相关酶活性及基因表达的影响。枇杷果实先用43 ℃热空气处理3 h,然后接种炭疽病菌,接种后的果实置于20 ℃条件下贮藏8 d。结果表明,热空气处理有效降低了枇杷果实的自然发病率,显著抑制了接种枇杷果实病斑直径的扩展,诱导了果实中几丁质酶、β-1,3-葡聚糖酶、苯丙氨酸解氨酶（PAL）和多酚氧化酶（PPO）等抗病相关酶活性的增强。热空气处理还可显著诱导接种枇杷果实PAL、PPO、过氧化物酶和热激蛋白基因的表达。同时,热空气处理对枇杷果实的硬度、可滴定酸和可溶性固形物含量等品质指标没有显著影响,但促进了类胡萝卜素的积累。以上结果表明,热空气处理可通过诱导抗病相关基因的表达和抗病相关酶活性的上升,提高枇杷果实的抗病能力。     

茉莉酸甲酯提高膜醭毕赤酵母对杨梅果实采后绿霉病生防效力的研究

研究了茉莉酸甲酯(Methyl jasmonate,MeJA)复合膜醭毕赤酵母(Pichia membranaefaciens)处理对"乌种"杨梅果实由桔青霉(Penicillium citrinum)引起的绿霉病的抑制效果,同时分析了MeJA对酵母菌和病原菌生长以及果实抗病性的影响。结果显示:MeJA可有效提升P.membranefacien生防效力,10μmol/L MeJA与1×109CFU/mL P.membranefacien菌悬液的复合处理比单一处理能更有效抑制杨梅果实绿霉病的发生;该复合处理也更为显著的诱导了杨梅果实抗病相关酶活性的上升;此外,MeJA还可直接提高P.membranaefaciens在NYDB培养基和杨梅果实伤口处的数量,但MeJA对病原菌P.citrinum生长无抑制效果。这些结果表明,MeJA主要是通过直接促进拮抗酵母生长以及间接诱导果实抗病性来提升P.membranaefaciens生防效力,从而起到有效抑制杨梅果实采后腐烂的作用。     

拮抗酵母结合热空气处理对采后海红果的保鲜效果

研究拮抗酵母结合热空气处理对提高采后海红果果实贮藏性能的效果。分别用107CFU/mL拮抗罗伦隐球酵母悬浮液浸泡处理2 min,36℃热空气处理海红果10 h以及二者结合先后处理海红果,于20℃下储藏15 d,贮藏期每3 d测定相关指标,研究不同处理对海红果果实贮藏期的保鲜效果。结果表明,热空气处理、拮抗酵母处理、先拮抗酵母后热空气处理和先热空气后拮抗酵母处理均能降低贮藏过程中海红果的失重率、腐烂率和丙二醛含量,提高SOD、CAT和POD活性,其中先热空气后拮抗酵母处理组的各项指标除POD外,其他均显著(P<0.05)优于单一处理组,表明先热空气后拮抗酵母处理海红果的保鲜效果优于单独处理方式;能明显降低果实水分和有机质的减少以及病害的发生率,提高果实抗氧化酶活性,减少丙二醛的积累,进而延缓细胞衰老,延长货架期。先36℃热空气处理10 h后107 CFU/mL罗伦隐球酵母悬浮液浸泡处理2 min是采后海红果果实保鲜处理的适宜方式。     

采后茉莉酸甲酯处理对富士苹果青霉病和贮藏品质的影响

以富士苹果为材料,研究采后茉莉酸甲酯（methyl jasmonate,MeJA）处理对果实损伤接种扩展青霉的抑制效果及对过氧化氢（H2O2）含量、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性及果实贮藏品质的影响。结果表明,100 μmol/L MeJA处理10 min对苹果果实青霉病的抑制效果最好,MeJA处理提高了果实SOD活性,促进了果实体内H2O2的积累,抑制了CAT的活性。此外,外源MeJA处理明显提高了果实抗坏血酸含量,降低了贮藏期间果实的质量损失率,对果肉硬度、可溶性固形物和可滴定酸含量无显著影响。由此推测,采后经MeJA处理的苹果果实抗病性提高和果实品质保持与抗氧化能力的提高有关。     

A combination of hot air treatment and nano‐packing reduces fruit decay and maintains quality in postharvest Chinese bayberries

BACKGOUND: Chinese bayberry is susceptible to microbial decay during postharvest handling and storage. To search for effective alternatives to currently used fungicides for disease control, the efficacy of hot air (HA) treatment at 48 °C for 3 h alone or in combination with nano‐packing (NP) containing nano‐TiO₂ and nano‐Ag in controlling green mould decay caused by Penicillium citrinum and natural decay, and their effects on fruit quality in harvested Chinese bayberries were investigated in this study. RESULTS: The combined treatment of HA and NP resulted in a remarkably improved control of green mould and natural decay in Chinese bayberries compared with treatment of HA or NP alone. The in vitro growth of P. citrinum was significantly inhibited by individual HA or NP. In addition, HA in combination with NP showed interactive effect on inhibiting fruit respiration, ethylene production and membrane lipid peroxidation, and maintained higher fruit firmness and DPPH radical scavenging activity. CONCLUSION: These results suggest that a combination of HA treatment and NP may be a useful technique to reduce fruit decay and maintain quality in Chinese bayberries during postharvest storage and retail conditions. Copyright © 2010 Society of Chemical Industry