Elaidinized Lipid in Relation to Its Effect on Emulsification

Emulsification as affected by substitution of elaidinized lipid was investigated. Cream puffs were prepared with lipids of 0, 40, 60 and 80 percent levels of substitution of elaidinized lipid for corn oil. Viscosity of the lipids at 61^oC was measured. Oil separation data were obtained from frozen, thawed and centrifuged batter. Penetrability of batters was measured. Volume by rapeseed displacement was determined for the baked products. Samples of batter, interior and crust were prepared for microscopic study by freeze-drying, staining of lipid with osmium tetroxide vapors, infiltration with paraffin and sectioning. Judges evaluated the sections on a descriptive score sheet. Batter sections for the four levels of substitution also were ranked in order of increasing dispersity of lipid.

Viscosity of the lipids increased with level of substitution of elaidinized lipid. The batters with elaidinized lipid at the zero and 40 percent levels showed more oil separation than those at the 60 and 80 percent substitution levels, although photomicrographic examination of batters revealed that dispersity of lipid decreased with substitution. Highly substituted lipid probably left the batter with difficulty because of relatively high viscosity. Differences in seepage from the baked products were observed visually; the less finely dispersed, highly substituted lipid was lost more readily than was the unsubstituted lipid. Batters with elaidinized lipid had relatively low penetrability; they also had relatively low volumes, probably because of greater resistance to expansion of the firmer batters. Judges did not detect any differences attributable to the four treatments for the interior and crust samples.

Substitution of elaidinized lipid for oil in cream puffs appeared not to be of practical benefit. The reduced tendency for lipid to separate from batter containing elaidinized lipid and subjected to a low storage temperature suggests a possible application in the making of mayonnaise.