Volatile markers of cholesterol thermal changes

The goal of the study was to determine profile of volatile compounds and asses the markers of cholesterol transformations during thermal processing using SPME-GC-MS technique. The profile of volatile compounds of cholesterol is dependent on the temperature (120, 150, 180 and 220 degrees C) and time (30, 60, 120 and 180min) used during processing. The highest contents of volatile compounds were observed during thermal processing of cholesterol at 180 and 220 degrees C. The most abundant group of volatiles were carbonyl compounds, for example, aldehydes, ketones and hydrocarbons. Statistical analysis of data allowed to point out markers of cholesterol changes like degradation, oxidation, polymerisation and formation of cholestadienes. 4-methylpentan-2-ol was recognized as possible marker of cholesterol oxidation, 6-methylheptan-2-one was markers of cholesterol degradation and 4-mehyldec-2-ene and 5-methylhexanal as markers of cholesterol polymerization. Volatile components that can be associated with formation of cholestadienes were 2-pentanone and 2-methylheptane. Practical application: The method reported in this study may be used for determination of volatile compounds in thermally processed sterol standards especially cholesterol. The developed method able us to determine the profile and content of volatiles, which were used during evaluation of cholesterol changes after thermal treatment. The reported data are crucial for assessment of markers of cholesterol degradation, for example, 6-methylheptan-2-one or thermal oxidation, for example, was 4-methylpentan-2-ol. Markers of cholesterol dimerization were 4-methyldec-2-ene and 5-methylhexanal. Moreover 2-pentanone and 2-methylheptane are volatiles which presence can be associated with formation of cholestadienes. This method can be used as evaluation method for changes of sterols, without a need of determination of sterols and other compounds like oxysterol, polymers of cholesterol and cholestadienes. During heating, cholesterol can undergo few processes for example degradation, polymerisation and oxidation. The aim of this study is to select volatile compounds, which can be used as markers of mentioned above processes. Due to performed SPME-GC-MS analysis of aroma components and other component like oxysterols, cholestadienes and cholesterol polymers (determined in previous study) and statistical analysis, it is possible to evaluate the volatile markers of particular processes for example 4-methylpentan-2-one as marker of cholesterol oxidation, 6-methylheptan-2-one as marker of cholesterol degradation and 5-methylhexanal as dimerization marker.