固相微萃取条件优化及福建红曲醋特征挥发性风味物质分析

Optimization of Solid Phase Microextraction Conditions and Analysis of Characteristic Volatile Flavor Compounds in Fujian Monascus Vinegar

摘要:

本研究通过顶空固相微萃取-气相色谱-质谱联用（HS-SPME-GC/MS）对福建红曲醋（永春老醋和永春香醋）中的挥发性风味物质进行分析，以峰面积为指标，确定固相微萃取最优条件为：50/30 μm DVB/CAR/PDMS萃取头，6 mL稀释10倍的醋样中添加1.5 g氯化钠，萃取温度50 ℃，萃取时间40 min。在该条件下采用HS-SPME-GC/MS共检测出福建红曲醋挥发性风味物质达63种，主要包括酯类（20种）、醇类（12种）、酸类（13种）、醛类（7种）、酮类(5种)、酚类（2种）、及其他类物质（4种）。热图分析发现，乙酸乙酯、苯乙醇、苯甲醛、乙酸异丁酯、雪松醇、乙偶姻和乙酸是永春老醋和永春香醋二者共有的主要香气成分，主成分分析发现，永春老醋密切相关的挥发性风味物质为乙酸异丁酯、2-乙酰氧基-3-丁酮和庚酸，而辛酸、2-十二醇、丁酸、苯乙烯、己酸乙酯和1-壬醇为永春香醋的密切相关的挥发性风味物质。

Abstract:

A method based on headspace solid-phase microextraction (HS-SPME) coupled to chromatography-mass spectrometry (GC-MS) was developed to quantify the volatile flavor compounds in Fujian Monascus vinegar (Yongchun aged vinegar and Yongchun aromatic vinegar). Optimal extraction conditions showed that incubation of 6 mL vinegar (diluted 10-fold) with 1.5?g of sodium chloride, an extraction time of 40?min, an extraction temperature of 50 ℃ using a DVB/CAR/PDMS fiber will give the best extraction. Under these conditions, totally 63 volatile flavor compounds were identified in Fujian Monascus vinegar, including esters (20), alcohols (12), acids (13), aldehydes (7), ketones(5), phenols (2) and others (4). Ethyl acetate, phenylethyl alcohol, benzaldehyde, isobutyl acetate, cedrol, acetoin and acetic acid were the main volatile compounds in Fujian Monascus Vinegar. Isobutyl acetate, 2-acetoxy-3-butanone and heptanoic acid were strongly associated with Yongchun aged vinegar, whereas octanoic acid, 2-dodecanol, butanoic acid, styrene, ethyl hexanoate and 1-nonanol showed statistically significant positive correlations with Yongchun aromatic vinegar.