Tsachaki Maroussa, Linforth Robert S T, Taylor Andrew J
Samworth Flavor Laboratory, Division of Food Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, United Kingdom.
J Agric Food Chem. 2005 Oct 19;53(21):8328-33. doi: 10.1021/jf051202n.
Static equilibrium headspace was diluted with a stream of nitrogen to study the stability of the volatile headspace concentration. The headspace dilution profile of 18 volatile compounds above aqueous and ethanolic solutions was measured in real time using atmospheric pressure chemical ionization-mass spectrometry. Under dynamic conditions the volatiles headspace concentration above water solutions decreased readily upon dilution. The presence of ethanol helped to maintain the volatile headspace concentration when the ethanol solution concentration was above 50 mL/L. This effect was such that under dynamic conditions the absolute volatile concentration above an ethanolic solution was higher than that above an aqueous solution, contrary to results observed in equilibrium studies. The ratio of the headspace concentration of volatiles above ethanolic 120 mL/L and water solutions was correlated to their air/water partition coefficient.
用氮气流稀释静态平衡顶空，以研究挥发性顶空浓度的稳定性。使用大气压化学电离质谱实时测量了水性和乙醇性溶液上方18种挥发性化合物的顶空稀释曲线。在动态条件下，水溶液上方的挥发性顶空浓度在稀释后很容易降低。当乙醇溶液浓度高于50 mL/L时，乙醇的存在有助于维持挥发性顶空浓度。这种效应使得在动态条件下，乙醇溶液上方的绝对挥发性浓度高于水溶液上方的浓度，这与平衡研究中观察到的结果相反。120 mL/L乙醇溶液和水溶液上方挥发性物质的顶空浓度之比与其气/水分配系数相关。
