Abstract: In this work, we explored the effects of white sugar and butter on sensory quality, specific volume, volume, texture and volatile flavor substances of bread made with a mixed starter culture of Saccharomyces cerevisiae and Lactobacillus plantarum. The results showed that addition of white sugar and butter could significantly improve the appearance, color, organizational structure, elasticity, smell and taste of bread, increasing bread volume by 13.80%, and decreasing hardness and elasticity by 35.35% and 37.91%, respectively. Principal component analysis (PCA) performed on electronic nose data showed that breads with sugar alone and in combination or with neither of them were clearly discriminated according to their volatile flavor components. Addition of white sugar and butter significantly changed the volatile flavor substances in bread samples, and had a significant impact on nitrogen oxides, sulfur compounds, aromatic compounds, aromatic hydrocarbons, methane and ethanol. The results of gas chromatography-ion mobility chromatography (GC-IMS) showed that addition of white sugar and butter significantly affected the type and concentration of volatile flavor substances in bread samples, significantly increasing the contents of methyl acetate, isoamyl acetate, ethyl caproate and furfural. These esters were not only volatile flavor substances, but also major aroma substances produced during fermentation. In conclusion, white sugar and butter play an important role in improving the eating quality of bread.

Key words: bread; white sugar; butter; flavor substances; gas chromatography-ion mobility spectrometry