Influence of dough composition on the formation of processing contaminants in yeast-leavened wheat toasted bread

Abstract

The influence of dough composition on acrylamide, 3-monochloropropane-1,2-diol (3-MCPD) esters, and glycidyl esters (GE) formation during bread toasting was investigated. The doughs differed in added amounts of soy lecithin, salt, and reducing agents (l-cysteine and glutathione). The toasting of bread for 2.5 min considerably enhanced the formation of acrylamide and 3-MCPD esters. The addition of lecithin (1%, w/w) resulted in four times higher content of 3-MCPD esters in toasted bread slices. No distinct relationship between dough composition and GE formation in untoasted and toasted bread was found. The addition of reducing agents (0.05%, w/w) mitigated during toasting not only the formation of 3-MCPD esters (more than six times) but also the extent of Maillard reaction that resulted in three times lower amounts of acrylamide and predominant formation of alcohol-like compounds. Toasted bread without reducing agents contained typical Maillard reaction compounds such as aldehydes, alkyl pyrazines, and derivatives of furan.

Keywords: 3-MCPD esters; Acrylamide; Glutathione; Glycidyl esters; L-cysteine; Soy lecithin; Toasted bread; Volatile compounds.