本文展开了乙醇浸泡对鲜切荸荠品质变化的研究，通过分析在贮藏期内鲜切荸荠的多酚氧化酶活性、呼吸速率、硬度、外观色度、气味、菌落总数及大肠菌群数等变化，确定乙醇浓度对鲜切荸荠品质的影响。结果表明：浸泡时乙醇浓度对鲜切荸荠中多酚氧化酶活性和荸荠硬度变化不显著，但对鲜切荸荠的呼吸速率、气味和外观色度影响显著。在贮藏1 d，当浸泡用乙醇浓度由15%增加到75%时，鲜切荸荠的呼吸速率由74 μg/(kg·h)增加到134 μg/(kg·h)；随着贮藏时间的延长，乙醇处理组鲜切荸荠的呼吸速率呈现下降趋势。色度分析知，贮藏0～4 d浸泡时乙醇浓度对荸荠色泽影响不显著；随着贮藏时间的延长，当浸泡乙醇浓度≥35%时，乙醇处理组的鲜切荸荠不产生黄化现象。电子鼻分析浸泡用乙醇浓度越高，在贮藏过程中生成的甲基类和醇、醛、酮类等物质越多，其中75%乙醇处理组荸荠对代表甲基类和醇、醛、酮类等物质的传感器R(6)和R(8)响应值分别由111.13和37.10上升至270.65和121.70。此外，乙醇可减少鲜切荸荠中的菌落总数和大肠菌群数；当浸泡时乙醇浓度由15%增加到35%时，贮藏至13 d荸荠中的菌落总数和大肠菌群数降低到可计数范围内；当浸泡时乙醇浓度大于55%时，在贮藏期内没有菌落总数和大肠菌群检出。在贮藏温度4 ℃、贮藏时间为13 d的条件下，用浓度35%～55%乙醇对鲜切荸荠进行浸泡处理，可显著延长鲜切荸荠的贮藏期。

In this study, the changes in the quality of fresh-cut water chestnut caused by the soaking in aqueous ethanol were examined.The changes of polyphenol oxidase activity, respiration rate, hardness, appearance color, odor, total number of colonies and number of coliforms of fresh cut mites during storage were analyzed. The effects of the ethanol concentration on the quality of fresh-cut water chestnut was evaluated through analyzing the activity of polyphenol oxidase, respiratory rate, hardness, color, flavor, total number of colonies and the number of coliforms of the fresh-cut water chestnut. The results showed that the ethanol concentration during soaking did not cause significant changes in the polyphenol oxidase activity and hardness of fresh-cut water chestnuts, but had significant effects on their respiratory rate, flavour and color.During 1 d storage, the respiration rate of fresh-cut water chestnut increased from 74 μg/(kg·h) to 134 μg/(kg·h) when the concentration of ethanol was elevated from 15% to 75%; The respiration rate of fresh-cut water chestnut treated with ethanol exhibited a downward trend over the storage . There was no significant change in the color of fresh-cut water chestnut within the first 4 d. With the prolongation of storage time, a high concentration of ethanol (≥35%) could prevent the change in the color of fresh-cut water chestnut from white to yellow. Analysis with an electronic nose showed that the higher the concentration of ethanol, the more the methyl groups and alcohols, aldehydes, ketones and other substances formed during storage. The response values of the sensors R(6) and R(8) corresponding to the methyl groups, alcohols, aldehydes,ketones increased from 111.13 and 37.10 to 270.65 and 121.70, respectively, when fresh-cut water chestnut treated with 75% ethanol. In addition,the ethanol treatment could reduce the total number of colonies and the number of coliforms in fresh-cut water chestnut. When the concentration of ethanol increased from 15% to 35%, the soaking led to the total number of colonies and the number of coliform in fresh-cut water chestnut(stored for 13 d) decreased to a countable range. When the ethanol concentration was greater than 55%, no colonies and coliforms were detected during the storage period. Thus, the shelf life of the fresh-cut water chestnut could be prolonged if they were soaked in 35%～55% aqueous ethanol and stored at 4 ℃ for 13 d.

湖北省重大科技创新项目（2017ABA153）；湖北省农业科学院基金（2018NKYJJ17）