Ohmic versus conventional heating for studying molecular changes during pound cake baking. (September 2019) - Deleu, Lomme J.
Abstract: Ohmic or electrical resistance (ER) heating of pound cake batter results in a crumb only cake that corresponds to the center of conventionally baked cake. ER heating in an ER oven (ERO) excludes significant temperature and moisture gradients during pound cake baking and was here combined with a proportional integral derivative (PID) controller imposing a predefined temperature-time profile corresponding to that in the center of a batter/cake during conventional (CONV) baking. As a result of this homogenous baking, in contrast to what is the case in CONV baking, there is no cold front in the batter where water condenses. Therefore, the sucrose concentration in ERO batter can be lower than in CONV batter while still obtaining similar extents of both starch gelatinization and protein network formation. This study also provides the insights that during the metamorphosis of batter into cake a primary role is to be attributed to protein network formation and that starch gelatinization only contributes in a later phase. Ohmic heating is thus an interesting method to study the mechanisms involved in cake baking. Highlights: Baking by ohmic heating strongly reduces temperature and moisture gradients during pound cake baking. More water is needed in pound cake recipe to gelatinize starch in absence of a cold front. Batter movement during ohmic heating is opposite to conventional baking. The metamorphosis of batter into cake is initiated by protein network formation.