Examining Oil Blends

August 26/Food & Farm Week -- "Blends of canola oil (CO) and fully hydrogenated cottonseed oil (FHCSO), with 20%, 25%, 30%, 35% and 40% FHCSO (w/w) were interesterified under the following conditions: 0.4% sodium methoxide, 500 rpm stirring, 100C, 20 minutes. The original and interesterified blends were examined for triacylglycerol composition, melting point, solid fat content (SFC) and consistency," investigators in Campinas, Brazil, report.

"Interesterification caused considerable rearrangement of triacylglycerol species, reduction of trisaturated triacylglycerol content and increase in disaturated-monounsaturated and monosaturated-diunsaturated triacylglycerols in all blends, resulting in lowering of respective melting points. The interesterified blends showed reduced SFC at all temperatures and more linear melting profiles if compared with the original blends. Consistency, expressed as yield value, significantly decreased after the reaction. Iso-solid curves indicated eutectic interactions for the original blends, which were eliminated after randomization. The 80:20, 75:25, 70:30 and 65:35 (w/w) CO: FHCSO interesterified blends showed characteristics which are appropriate for their application as soft margarines, spreads, fat for bakery/all-purpose shortenings, and icing shortenings, respectively.

"PRACTICAL APPLICATIONS: Recently, a number of studies have suggested a direct relationship between trans isomers and increased risk of vascular disease. In response, many health organizations have recommended reducing consumption of foods containing trans fatty acids. In this connection, chemical interesterification has proven the main alternative for obtaining plastic fats that have low trans isomer content or are even trans isomer free," wrote A.P.B. Ribeiro and colleagues.

The researchers concluded, "This work proposes to evaluate the chemical interesterification of binary blends of canola oil and fully hydrogenated cottonseed oil and the specific potential application of these interesterified blends in food products."

Ribeiro and colleagues published their study in the Journal of Food Lipids ("Effect of Chemical Interesterification on Physicochemical Properties and Industrial Applications of Canola Oil and Fully Hydrogenated Cottonseed Oil Blends." Journal of Food Lipids, 2009;16(3):362-381).

For additional information, contact A.P.B. Ribeiro, State University Campinas UNICAMP, Dept. of Food Technology, Faculty Food Engineering, CP 6041, BR-13083970 Campinas, SP, Brazil.

From the August 31, 2009, Prepared Foods E-dition