Impact of sugar and egg proteins on the physico-chemical properties of cake batters

Starch is the major ingredient in cakes and other bakery products. Its gelatinization plays an important role with the protein network on cake structure firming. This work focused on starch in complex systems in the presence of sugar, fat, eggs and pregelatinized wheat or maize starches and its effect on the end-use properties of cakes. Model systems and microcakes (without baking powder) were used in this study. Micro-calorimetry (MDSC) and micro-viscoamylograph (MVAG) were used to determine the effect of batter ingredients on starch thermal and pasting properties. The texture of microcakes was evaluated by a compression test. Egg addition decreased the gelatinization endotherm observed at 63°C and it merged with denaturation peak around 78°C at 30% water content. When egg and sugar were added, the gelatinization endotherm shifted to higher temperature to 93°C. This suggests that sugar is competing with starch for water and decreased the available water for its gelatinization. With the MVAG, egg addition to flour increased the peak viscosity from 373±49 mPa*s to 657±16 mPa*s, likely due to the egg protein denaturation. The increase was more prominent when the eggs and sugar were added. When 20% of flour was replaced by the pregelatinized wheat or maize starch, a decrease in peak viscosity and setback was observed for all mixtures. This may be due to the decrease in the native starch content when the pregelatinized starch (PS) that was used. This decrease of PS addition could explain the texture improvement in microcakes - the Young’s modulus decreased by 56%. The association of these different techniques helped to better understand the effect in batter of different ingredients on starch properties that are important for improving the texture and shelf-life of these high sugar and fat content cakes.