Mitigation role of erythritol and xylitol in the formation of 3-monochloropropane-1,2-diol and its esters in glycerol and shortbread model systems

The effect of the addition of six sweeteners (erythritol, xylitol, maltitol, sucrose, steviol sweetener, and stevia leaves) on the formation of 3-monochloropropane-1,2-diol (3-MCPD) and 3-MCPD esters in glycerol and shortbread model systems subjected to heat treatment was investigated. The highest level of free 3-MCPD was reached for the glycerol model system with the addition of steviol sweetener (114.8 mu g kg(-1)), in contrast to the model with stevia leaves (51.9 mu g kg(-1)). The level of free 3-MCPD in the shortbread model was roughly similar, whilst the levels of esterified 3-MCPD were about 12 times higher. The maximum content was obtained in the model with sucrose (1112 mu g kg(-1)) and the lowest with erythritol (676.4 mu g kg(-1)). In the glycerol model system, 3-MCPD esters were not detected at all. The experiment revealed that acidic conditions, generated mainly by thermal decomposition of glucose, were a key factor promoting the formation of free and bound 3-MCPD, while in the case of the application of polyols, especially erythritol or xylitol, the chloropropanol production was significantly lower. The experiment also showed that antioxidant capacity of products formed under heat treatment (0.53-1.03 mol Trolox kg(-1)) might have some significance in 3-MCPD formation. The findings of the study suggest that erythritol and xylitol added instead of sugar to shortbread can be effective agents in the mitigation of free and bound 3-MCPD formation. However, we also revealed that the application of sweeteners based on maltodextrin or pure stevia extract did not show any inhibitory effect, and in some cases led to the increase in the 3-MCPD generation, so their use in the bakery industry should be reconsidered.