褪黑素和短波紫外联合处理对鲜切麻竹笋挥发性化合物的影响

摘要：目的：褪黑素和紫外照射(ultraviolet C, UV-C)处理能有效抑制鲜切麻竹笋褐变、腐烂等品质劣变现象。本研究拟进一步探究两种处理方式对麻竹笋香气的影响。方法: 利用气相色谱离子迁移谱联用技术(gas chromatography-ion migration spectrometry, GC-IMS)对麻竹笋挥发性香气进行分析。结果：GC-IMS检测结果结合表明麻竹笋挥发性成分以醇、醛和酯为主。鲜切麻竹笋中鉴定出70种挥发性化合物，包括18种醇、9种醛、4种酮、9种烯烃、10种酯、3种酸和7种其他挥发性化合物。紫外照射和褪黑素处理显著抑制鲜切笋发酵过程并且改变挥发性酯的种类和含量，导致2-甲基丁酸乙酯、乙酸乙酯、醋酸甲酯、丁酸丙酯明显积累。与单独紫外照射或褪黑素处理不同，联合处理可以提高反式2-丁烯乙酯、2-辛醇、3-甲基戊醇、丙酸含量，并抑制发酵过程中不良风味如对甲酚的积累。3-甲基吲哚、安息香醛、对甲酚、反式-2-庚烯醛可以作为判别不同处理贮藏麻竹笋的主要特征性标志物。结论：本文初步探究了褪黑素联合紫外处理对鲜切麻竹笋风味物质的影响，为鲜切麻竹笋保鲜提供理论支撑。

Effects of combined treatment of melatonin and ultraviolet C on volatile compounds of fresh-cut Ma bamboo shoots

ABSTRACT: Objective: Melatonin and ultraviolet C irradiation (UV-C) can effectively inhibit the browning, decay and other quality degradation of fresh-cut bamboo shoots. This study intends to further explore the effects of the two treatment methods on the aroma of Ma bamboo shoots. Methods: Gas chromatography-ion migration spectrometry (GC-IMS) was used to analyze the volatile aroma of Ma bamboo shoots.. Results: The results of GC-IMS showed that alcohol and aldehydes were the main volatile components of Ma bamboo shoots. Seventy volatile compounds were identified in fresh-cut Ma bamboo shoots, including 18 alcohols, 9 aldehydes, 4 ketones, 9 alkenes, 10 esters, 3 acids and 7 other volatile compounds. UV irradiation and melatonin treatment significantly inhibited the fermentation process of fresh shoots and changed the types and contents of volatile esters, resulting in significant accumulation of ethyl 2-methylbutyrate, ethyl acetate, methyl acetate, and propyl butyrate. Different from UV or melatonin treatment alone, combined melatonin treatment could increase the contents of trans-2-butenethyl, 2-octanol, 3-methylpentanol and propionic acid, and inhibit the accumulation of undesirable flavor such as p-cresol during fermentation. 3-methylindole, benzoaldehyde, p-cresol and trans-2-heptenal can be used as the main characteristic markers to distinguish different treatments of stored Ma bamboo shoots. Conclusion: This study preliminarily explored the effects of melatonin combined with UV treatment on flavor substances of fresh-cut bamboo shoots, which provided theoretical support for fresh-cut bamboo shoots preservation.