HOT-STAGE MICROSCOPY OF CAKE BATTER BUBBLES DURING SIMULATED BAKING -SUCROSE REPLACEMENT BY POLYDEXTROSE

A hot-stage video microscopical technique was developed to study the e ffects of sucrose replacement by polydextrose (weight for weight basis ) on the foam characteristics of cake batters, before and during heati ng. Polydextrose substitution increased the mean size of air-bubbles i n the cake batter and introduced a larger variation in bubble size dis tribution than the sucrose batter. The differences between sucrose and polydextrose batters on initial bubble size distribution were reflect ed in expansion rates of bubble populations during heating. The lack o f uniformity in the bubble distribution of batters containing polydext rose increased the rate of gas diffusion from small bubbles to larger ones. On heating, the bubble population of sucrose batters expanded mo re than that of polydextrose substituted batters.