The effects of adding “flavour enhancers” on levels of chloropropanediol esters and glycidyl esters in savoury shortbread

The effect of the addition of selected flavour enhancers (dried garlic, dried onion, caraway seeds, poppy seeds, kelp, sesame, Herbs de Provence) on levels of chloropropanediol esters (2-MCPDE, 3-MCPDE) and glycidyl esters (GE) was investigated in classic savoury shortbread with standard and reduced salt level. The changes in the amount of esters after a 2-month storage period were also analysed. Finally, selected products with reduced salt level were evaluated by consumers. The obtained results suggested that the MCPDE and GE present in bakery fat were transferred to the dough and partially decomposed during baking. Ester degradation depended on the presence of flavour additives and the amount of salt. The addition of poppy seeds or sesame accelerated the degradation, whereas onion and garlic inhibited the decomposition and, in some cases, promoted the endogenous formation of 3-MCPDE. The added salt also partially inhibited the decomposition of 3-MCPD esters but had no impact on 2-MCPDE changes. After a 2-month storage period, the level of 3-MCPDE increased in all samples that did not contain salt, while in salty products as well as for 2-MCPDE no such trends were observed. GE levels decreased after 2 months in almost all investigated samples. The consumer acceptability tests showed that the addition of poppy seeds or sesame seeds to the shortbread with reduced salt was highly evaluated by consumers. Hence, the addition of these flavour enhancers can mask the reduced salt amount, thereby lowering not only the level of sodium in the diet, but also the levels of toxic contaminants such as MCPDE or GE.