Effect of sweeteners on acrylamide formation in extruded breakfast cereals

Sammanfattning: Acrylamide is a possible carcinogen to humans, formed upon heat-treatment of carbohydrate-rich foodstuffs via the Maillard reaction. Reducing sugar and the amino acid asparagine are the primary precursors for acrylamide formation, of which free asparagine is the limiting factor. Among the foods being subjected to acrylamide formation, breakfast cereal is one. Substitution of sucrose with alternative sweeteners such as fruit juice concentrate in extruded breakfast cereals has been linked to increased content of acrylamide. Therefore, this literature study aimed to review how the usage of alternative sweeteners can affect acrylamide formation in the manufacture of extruded breakfast cereals. Furthermore, a fruit juice analysis was done in order to determine whether concentrated fruit juice may contribute to the formation of acrylamide. Free asparagine was the major amino acid determined in both of the concentrated apple juice samples. The content of free asparagine was considerably lower than the content of reducing sugars, confirming that free asparagine is the limiting factor in the formation of acrylamide. Acrylamide was formed in concentrated fruit juice upon analysis, indicating that there is a possibility for developing acrylamide under right conditions in the final product containing concentrated fruit juice. Thus, to reduce the amount of acrylamide being formed in extruded breakfast cereals, the sources of free asparagine should be minimised. As the content of free asparagine varies between different fruits, a concentrated fruit juice with lower free asparagine content should be favoured in the manufacture. Also, a sweetener absent in free asparagine could be chosen in front of concentrated fruit juice. Treating the concentrated fruit juice is another possibility to reduce the content of free asparagine. This study confirms that the concentrated fruit juice may influence the total amount of acrylamide being formed in extruded breakfast cereals. More research is warranted to examine the correlation between alternative sweeteners and acrylamide formation in breakfast cereals. Research on the physiological and metabolic function of free asparagine in plants is also needed.