ENZYME-RESISTANT STARCH IN YELLOW LAYER CAKE

Enzyme-resistant starch (RS) from amylomaize VII starch replaced up to 50% of the total shortening (40 parts per 100 parts of flour) and up to 15% of the flour in a yellow layer cake. Starch gelatinization and melting of the amylose-lipid complex, as determined by differential sc anning calorimetry, were delayed by a high concentration (100 parts pe r 100 parts of flour) of sugar in the cake batter. The melting tempera ture for RS was also raised by the high concentration of sugar. The en dothermic peak for melting of RS was decreased by the limiting amount of water in the cake system. In cakes in which RS replaced 15% of the flour, no significant effects were recorded on physical characteristic s (specific gravity of batter, cake weight and volume, water activity, moisture, and softness [determined by a compression test]) and scanni ng electron microscopy pictures. Cake batters containing shortening an d RS incorporated similar amounts of air, but the air cell numbers dec reased as increasing levels of shortening were replaced by RS. As the level of shortening replacement increased, cake crumb became more comp act. A high degree of shortening replacement also reduced the volume a nd firmed the cake. However, when RS was used at a low replacement lev el (12.5%), yellow layer cake quality was improved. RS in the cake bat ter or cake crumb could be detected in samples in which 50% of the sho rtening was replaced by RS.