Determination of the Volatile Components

The metabolic activity of sourdough microbial community is exploited not only to leaven dough but also to produce a complex array of volatile and nonvolatile flavor compounds that influence the sensory properties of the final bread product. The sourdough and the processing parameters applied in the production of sourdough bread affect both the diversity of microorganisms and their metabolic activity and flavor generation during fermentation. Volatile organic compounds (VOCs) are important contributors to the characteristic flavors and off-flavors of baked goods, affecting the overall acceptability to consumers. A wide range of volatile compounds have been identified in sourdough bread, including acids, alcohols, aldehydes, esters, ketones, lactones, hydrocarbons, pyrroles, pyrazines, and sulfur compounds. The gas chromatography — mass spectrometry (GC—MS) analysis have been described for VOC detection, by using a method for volatile extraction based on headspace solid phace microextraction (HS—SPME). This chapter will provide a description of HS-SPME GC-MS analysis for the evaluation of volatile compounds in sourdough bread including sample treatment, HS-SPME conditions, GC-MS conditions, as well as quantification methods.