Ningjian Liang, Xiu-Min Chen and David D Kitts
Health agencies state that total dietary energy intake should not exceed a maximal of 25% of calories derived from added sugars. Bakery products are major food sources that contribute to the added sugars intake; however potential sugars losses due to Maillard reaction and caramelization, occur at typical baking temperatures. In this study we employed markers associated with non-enzymatic browning, that corresponded to loss of free sugars, generation of α-dicarbonyl compounds with changes in caloric content of digestible constituents in sugar-amino acid model and cake formulations. Sugars losses in simple model systems that reached 100 percent after 40 min baking at baking temperatures of 150°C and 180°C corresponded to reduced calorie content, in fractions with a MW<3000 (p<0.05). In comparison, less gross energy calories from sucrose were lost after a similar heat treatment in sucrose-amino acid mixtures. Model cakes baked at 150°C and 180°C, respectively followed this trend with invert sugar, having greater losses losses (p<0.01) than cakes containing sucrose. We conclude that thermal temperatures typical of baking that result in non-enzymatic browning reactions, reduce both the total sugars and corresponding calories due to conversation to non-bioavailable high molecular weight browning products.