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°C, 150°C, 180°C and 220°C) and time (30, 60, 120 and 180 minutes) used during processing. The highest contents of volatile compounds were observed during thermal processing of cholesterol at 180°C and 220°C. The most abundant group of volatiles were carbonyl compounds e.g. 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 applications: 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 e.g. 6-methylheptan-2-one or thermal oxidation e.g. 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.