Functionality of emulsifiers in sponge cake production

The effects of emulsifiers (glyceryl monostearate and polyglycerol ester) and air inclusion on the structure of sponge batters were studied. Batter samples, immediately after mixing in a continuous mixer, were imaged for bubbles using an optical microscope and a CCD video camera. The bulk rheology of the batters was also determined to characterise their physical properties. The aqueous phases of the batters were separated by centrifugation and their surface tension was measured. The crumb structure of the finished sponge cakes was studied using a commercial texture analyser. The results showed that addition of an emulsifier helped in binding water and decreased the fluidity of the batter as well as the tension of the air/aqueous phase interface. Increasing the concentration of the emulsifier affected the distribution and size of the air bubbles trapped in the batter during mixing as well as the texture and volume of the baked sponge.