1-甲基环丙烯对红星苹果常温贮藏期间生理、品质和电子鼻特性的影响

Effect of 1-Methylcyclopropene on the Physiology,Quality and Electronic Nose Characteristic of Starking Delicious Apple During Ambient Temperature Storage

为了探讨1-甲基环丙烯(1-MCP)对红星苹果贮藏品质、生理以及电子鼻特性的影响,以红星苹果为研究对象,测定1-MCP处理后常温贮藏(20±1)℃过程中果实呼吸速率、乙烯释放速率、内在品质及外观色泽和电子鼻响应情况。结果表明:随着贮藏时间延长,红星苹果采后呼吸速率、乙烯释放速率升高,分别于10,15 d达峰值后降低。同时,果实硬度下降、可滴定酸含量降低,SSC先升高后降低;果皮a^(*)值、b^(*)值、C^(*)值和ΔE^(*)值升高。1-MCP处理抑制红星苹果贮藏期呼吸速率和乙烯释放速率,延缓果实硬度、SSC和TA含量下降,同时抑制果皮a^(*)值、b^(*)值、C^(*)值和ΔE^(*)值升高。电子鼻检测表明,1-MCP处理明显减少了硫化物和萜烯类化合物(W1W)、氮氧化合物(W5S)、有机硫化物和芳香族化合物(W2W)、甲基类芳香物(W1S)以及醇类和醛酮芳香化合物(W2S)的生成。判别分析(LDA)能区分不同贮藏时期对照和1-MCP果实的电子鼻感应值。载荷分析表明,W1W、W5S、W2W、W1S和W2S等5个传感器对区别不同贮藏时期对照和1-MCP处理的贡献较大。1-MCP处理可延缓红星苹果软化,使其保持较低的固酸比,对于维持常温贮藏下果实风味和色泽具有显著效果;但1-MCP降低了果实电子鼻敏感传感器的响应值,在一定程度上减少了挥发性物质的生成。相关分析表明,红星苹果电子鼻敏感探头响应值与果实品质显著相关,为电子鼻作为红星苹果快速无损检测提供了依据。

In order to investigate the effect of 1-methylcyclopropene(1-MCP)on the physiology,storage quality and electronic nose characteristic of Starking delicious apple.Fruits were treated with 1-MCP and then stored at ambient temperature(20±1)℃.Respiration rate,ethylene production rate,fruit intrinsic quality,color difference and the electronic nose response was analyzed during storage.The results showed that the postharvest respiration rate and ethylene release rate of Starking delicious apple increased at first,then decreased after peaking at 10 d and 15 d,respectively.At the same time,fruit firmness and titratable acid(TA)content decreased,soluble solid content(SSC)increased then decreased.Fruit chromaticity varied,a^(*),b^(*),C^(*)andΔE^(*)values increased.1-MCP treatment inhibited fruit respiration rate and ethylene release rate,delayed the decline of fruit firmness,SSC and TA content,inhibited increasing of a^(*),b^(*),C^(*)andΔE^(*).1-MCP treatment significantly reduced the production of sulfides and terpene compounds(W1W),nitrogen oxides(W5S),organic sulfides and aromatic compounds(W2W),methyl aromatic compounds(W1S),alcohols,aldehydes and ketones aromatic compounds(W2S).Linear discriminant analysis(LDA)combined with electronic nose could distinguish control and 1-MCP fruit at different storage periods.Loading analysis showed that W1W,W5S,W2W,W1S and W2S sensors played key roles in differentiating control and 1-MCP treatment fruit during storage.During ambient temperature storage,1-MCP treatment delayed fruit softening and kept a lower solid-acid ratio,effectively maintained fruit flavor and color of Starking delicious apple.However,1-MCP decreased the response value of sensitive sensors in electronic nose,and inhibited the production of fruit volatile substances.According to correlation analysis,electronic nose sensor response values were significantly correlated with the internal quality and color difference,which may provide a basis for the rapid and nondestructive detection of Starking delicious apple.