Trans Isomers in Relation to Their Effect on the Aeration Function of a Shortening

Lipid effects on aeration of batters and sensory attributes of cakes were investigated. The shortenings were prepared from lard with elaidinized vegetable oil substituted at the 0, 40, 60 and 80 percent levels. These levels of substitution represented trans isomer contents of 0 to 56 percent of the total monoene. Penetrability of the manipulated lipids decreased with increasing elaidinized lipid substitution.

Viscosity and density determinations were made on the batters. Viscosity increased (P<0.01) up to the 60 percent level of substitution, at which level density was the lowest (P<0.01).

Volume index was measured as the area (cm²) of the center-cut cross-section. Cakes made with unsubstituted lard were smallest (P<0.01) and those made from lipid at the 80 percent substitution level were largest (P<0.01).

The sensory panel judged the cakes made of unsubstituted shortening to be of highest quality (P<0.01) and those made from lipid at the 80 percent substitution to be of lowest quality (P<0.01).

Addition of elaidinized lipid to lard up to the 60 percent level of substitution increased aeration during mixing and the cakes produced at the 40 and 60 percent substitution levels had acceptable sensory qualities.