番茄新鲜度与其挥发性成分的关系研究

HS-SPME-GC-MS Study on the Relationship between the Freshness of Tomato and Its Volatile Components

摘要:

采用顶空固相微萃取-气相色谱-质谱联用技术分析了新鲜番茄在高温加速失鲜（38℃±1℃）和低温保鲜（4℃±1）环境下挥发性成分的变化及其失鲜的特征性气味成分，同时分析了番茄的新鲜度指标。结果表明：番茄在高温环境中保藏至第6d时失鲜，乙酸乙酯、乙醇、反式-2-己烯醛、1-辛烯-3-醇、1-庚醇、乙酸等为高温环境下失鲜的特征性气味成分。番茄在低温保鲜条件下第14 d开始失鲜，乙醇、2-己烯醇、α-法尼烯、乙酸、1,1-二乙氧基辛烷、辛醇、辛酸等为其失鲜时的特征性气味成分。番茄失鲜后其可溶性固形物含量及果实硬度下降，pH值、失重率上升。乙醇为番茄失鲜的特征性气味成分，其阈值为234.48 ?g/L。研究为通过检测挥发性气味成分判断番茄新鲜度提供了理论依据，亦可据此研发基于挥发性成分判断番茄新鲜度的智能冰箱，但探头响应阈值的设定还需要进一步探索。

Abstract:

Changes in the volatile components of tomatoes and the characteristic odor components arising from high-temperature (38°C ± 1 ℃, reduces freshness) and low-temperature (4 ℃± 1 ℃, preserves freshness) storage were analyzed by headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS). Additionally, the indexes of tomato freshness degree were analyzed. Tomatoes in the high-temperature environment lost their freshness on the 6th day, with ethyl acetate, ethanol, trans-2-hexenal, 1-octen-3-ol, 1-heptanol, and acetic acid being the resultant characteristic odor components. Tomatoes in the low-temperature environment started losing freshness on the 14th day, where ethanol, 2-hexen-1-ol, α-farnesene, acetic acid, 1,1-diethoxy-octane, octanol, and octanoic acid were the characteristic odor components. After loss of freshness, the content of soluble solids and the hardness of the tomato fruits decreased, while the pH value and the rate of weight loss increased. Ethanol was the characteristic odor for tomatoes with reduced freshness, with a threshold value of 234.48 μg/L. This study provides a theoretical basis for judging the freshness of tomatoes by measuring their volatile components. Meanwhile, the results can be used to develop a smart refrigerator to determine the freshness of tomatoes via detection of their volatile components. However, the set of threshold values of the probe needs further exploration.