Chemical changes in wheat pan bread during storage and how it affects the sensory perception of aroma, flavour, and taste

Wheat bread and whole wheat bread were stored for up to 3 weeks and specific chemical reactions were related to perceptual flavour changes as analysed by sensory profiling. Volatile and non-volatile compounds were quantified using GC MS and HPLC. Results were examined by multivariate data analysis. Fresh wheat bread had a higher concentration of the fermentation products 2,3-butandione and 3-hydroxy-2-butanone and the Strecker aldehydes 2- and 3-methylbutanal. The fresh bread and bread stored for 1 week were described by dough and bran aroma and flavour whereas samples stored 2 and 3 weeks were characterised by dust aroma and flavour together with bitter taste. Bread stored 2 and 3 weeks generally had a higher content of secondary lipid oxidation products than the more fresh samples. The total content of soluble phenolic acids stayed unchanged during storage. Most sensory attributes could be directly related to changes in the chemical composition of volatiles. The formation of off-flavours in bread could be related to the formation of secondary lipid oxidation products together with decreasing levels of compounds from Maillard reactions. (C) 2011 Elsevier Ltd. All rights reserved.