Characterizing quality of rendered duck fat compared to other fats and oils

The characteristics of rendered duck fat (RDF) were compared to commercial sources of soybean oil, lard, tallow, butter and olive oil. RDF was highly susceptible to lipid oxidation during storage compared to the other fats and oils. However 0.005% tert-butyl hydroquinone delayed the onset of lipid oxidation to an extent that was comparable to the lag phase observed in the commercial fats and oils. Positive attributes of RDF included a relatively high oleic acid content and low saturated fat content. Undesirable attributes of RDF included a lack of conjugated linoleic acid (CLA) and intermediate levels of trans fatty acids (TFA) compared to the other lipid sources. Decreasing the time and temperature of rendering decreased the TFA content in RDF. Around one-half of the TFA content in RDF was vaccenic acid which is converted to CLA after ingestion.