Improve creaming and aeration properties of milkfat fractions.

Butter and anhydrous milkfat have been replaced by vegetable shortenings for many applications in the baking industry. Many times the poor performance of butter in bakery products, compared with specialty vegetable shortenings, is a drawback to the image and flavor of butter. With this in mind, researchers at the University of Wisconsin (Department of Food Science, Babcock Hall, Madison, WI 53706) are trying to overcome the limitations of poor creaming and aeration of milkfat in cakes, cookies and icings in order to expand opportunities for using milkfat and milkfat fractions in baked goods.

Cake volume is governed by the creaming and aeration properties of shortenings or fats in cake batters. Creaming results from fat particles incorporating and stabilizing air bubbles in cake batter. The entrapped air provides a way for cake volumes to expand during baking. Generally, higher cake volumes are considered desirable, given that other structural features of the cake remain within acceptable parameters. The type of shortening employed in the preparation of cake batters greatly affects creaming functionality. Specialty vegetable shortenings manufactured specifically for this application provide superior functionality to intact butter.

Measuring the specific gravity of cake batters provides an index of the degree of aeration achieved in batters, and measuring the volume of finished baked cakes is a way to assess the final functionality of the shortening in relation to air retention. Researchers chose butter pound cakes as the model for studies on cakes. In these studies, investigators found that vegetable shortenings performed better than butter or anhydrous milkfat.

Investigations into the effects of mixing temperatures for cake batters upon creaming showed that relative creaming functionality or efficiency of milkfat and butter improved as the temperature decreased from 29 C to 13 C. Texturizing or physically reducing the size and increasing the numbers of milkfat crystals greatly improved the creaming functionality of anhydrous milkfat. This approach increased cake volumes and decreased the instrumentally-measured firmness of cakes. The result was a more moist finished cake.

Several emulsifiers were evaluated for their ability to improve the creaming and aeration capabilities of anhydrous milkfat. The use of lecithin yielded only marginally-acceptable cakes, and over-emulsification was frequently encountered. This resulted in the destabilization and collapse of the foam structure during baking. However, adding 1% mono- and di-glycerides significantly improved cake volumes. This emulsifier system appears to be highly compatible and functional in anhydrous milkfat. Studies with milkfat fractions revealed that texturized middle- and higher-melting fractions containing monoglycerides performed comparable to vegetable shortening in pound cakes. However, lower-melting milkfat fractions performed inadequately in pound cakes because they lacked suitable solid fat crystals to stabilize air bubbles in batters.

Butter cream icings prepared with milkfat fractions were characterized for volume, stability and sensory characteristics. Higher-melting fractions provide improved icings compared with intact butter and lower-melting milkfat fractions. Further information. Robert Lindsay; phone: [phone]; fax: [phone].