It has been said since ancient times that the secret to making bread is flour, yeast, and technique. Although the amount used is small, yeast is one of the most important ingredients. The yeast enzyme breaks down sugars to produce carbon dioxide, which is then wrapped in a gluten membrane, and the dough expands and hardens during baking to make bread. This expansion increases the commercial value of bread, improves cooking and digestibility, and the volatile compounds produced by fermentation improve the smell and taste. Recently, in Japan, the use of levain yeast, which is mainly composed of lactic acid bacteria, has been attracting attention for its improved flavor, which is a quality characteristic of deliciousness. In this study, in order to clarify the characteristics of the flavor components of levain yeast bread, flavor analysis was performed on levain yeast bread and conventional yeast bread on the first to fifth days after baking. The flavor components were measured using high-performance liquid chromatography (HPLC) and gas chromatography/mass spectrometry (GC/MS) to measure the free amino acid and sugar content. In addition, a comprehensive analysis of odors was performed using a two-dimensional gas chromatograph time-of-flight mass spectrometer (GC×GC-TOFMS), and the analyzed data was subjected to multivariate analysis using JMP Pro 17.
