Publication no. C-2002-0605-01R |  VIEW ARTICLE

Microstructure of alpha-Crystalline Emulsifiers and Their Influence on Air Incorporation in Cake Batter.

G. Richardson (1), M. Langton (1,2), P. Fäldt (3), and A.-M. Hermansson (1). (1) SIK—The Swedish Institute for Food and Biotechnology, PO Box 5401, S-402 29 Göteborg, Sweden. (2) Corresponding author. Phone: +46-31-3355600. Fax: +46-31-833782. E-mail: <ml@sik.se> (3) Aromatic AB, PO Box 440 40, S-100 73 Stockholm, Sweden. Cereal Chem. 79(4):546-552. Accepted March 18, 2002. Copyright 2002 American Association of Cereal Chemists, Inc.

The microstructure of alpha-gel and beta-crystalline emulsifiers and their effects on cake batter foam have been studied with polarized light microscopy, confocal laser scanning microscopy (CLSM) and image analysis, freeze-etching, and transmission electron microscopy (TEM). The emulsifiers Colco and Aroplus, which are commercial alpha-gels, and the monoglyceride Dimodan P in its alpha-gel and beta-crystalline forms were added to the batter in concentrations of 0.8, 2.0, 3.1, and 4.2%. Dimodan P alpha-gel was also prepared with three NaCl concentrations (0.05, 0.67, and 1.35‰). The distribution of air in the foam was evaluated with density measurements and with image analysis of bubbles in optically sectioned batter. In the cake batter, all the alpha-gel emulsifiers decreased the density, thereby increasing the incorporation of air, more than the beta-crystalline emulsifier, which did not have any effect on the density. There were noticeable differences in microstructure between the different alpha-crystalline emulsifiers. Large, regular alpha-structures seemed to increase the batter volume and interfacial area more than smaller aggregates. Adding salt in the emulsifier gel changed the structure, probably into alpha-lamellar liposomes, which impaired the aerating effect at lower concentrations.