基于GC-IMS分析炒制温度对青稞糌粑粉挥发性风味物质的影响

GC-IMS-Based Analysis of the Effect of Frying Temperature on Volatile Flavor Substances in Highland Barley Tsampa Flour

为明确不同炒制温度及粒色对青稞糌粑粉挥发性风味物质(Volatile organic compounds,VOCs)的影响,采用气相色谱-离子迁移谱(Gas chromatography-ion mobility spectrometry,GC-IMS)对黑青稞芶芒紫(BHB)、白青稞昆仑-15(WHB)在不同炒制温度(160、180、200、220和240℃)下糌粑粉中VOCs进行分析。结果表明,受试样品中共检测出62种化合物,可准确识别的有44种有机物,包含19种醛类、10种醇类、5种酮类、5种酯类、4种吡嗪类和1种呋喃类;炒制对糌粑粉VOCs的组成具有显著影响,随着炒制温度的升高,醇类VOCs总量呈逐渐下降的趋势,醛类、酮类、酯类、吡嗪类、呋喃类VOCs则呈增加的趋势;吡嗪类、醛类和酮类是青稞糌粑粉VOCs的特征性和主要的风味物质,在较高温度(220、240℃)下炒制有利于其产生;WHB中VOCs随炒制温度的变化更加显著,除呋喃类VOCs外,其他类化合物相对变化量均高于BHB;由主成分分析可知BHB和WHB糌粑粉风味存在显著差异,可以分为两种不同的风味类型。本研究有望为青稞糌粑粉生产技术规范的制定提供理论依据。

To clarify the effects of different frying temperatures and grain colors on volatile organic compounds(VOCs)in highland barley(HB)tsampa flour,gas chromatography-ion mobility spectrometry(GC-IMS)was used to analyze the VOCs in two types of HB with two colors,Goumangzi and Kunlun-15.The VOCs were analyzed at different frying temperatures(160,180,200,220 and 240℃).The results showed that a total of 62 compounds was detected,among which 44 organic compounds could be accurately identified,including 19 aldehydes,10 alcohols,5 ketones,5 esters,4 pyrazines and 1 furan.Frying had a significant effect on the composition of VOCs in tsampa flour,with the increase of frying temperature,the total amount of alcohol VOCs tended to decrease gradually,while aldehydes,ketones,esters,pyrazines and furans VOCs tended to increase.Pyrazines,aldehydes and ketones were the characteristic and main flavor substances of HB tsampa flour,and frying at higher temperature(220,240℃)was favorable to their production.The variation of VOCs with frying temperature was more significant in WHB,except for furan VOCs,the relative changes of other compounds were higher than those in BHB.The principal component analysis showed that there were significant differences in the flavor of BHB and WHB tsampa flour,which could be classified into two different flavor types.This study was expected to provide a theoretical basis for the development of technical specifications for the production of highland barley tsampa flour.