Phase behavior of a binary lipid shortening system: From molecules to rheology

Abstract

AbstractThe phase behavior of fully hydrogenated canola oil in soybean oil was investigated using iso‐solid lines from temperature‐controlled pulse‐NMR along with DSC data, with the rate of cooling of crystallized samples kept constant. The molecular diversity within the fat system was investigated using HPLC and GC. The microstructure of the fats was determined using a temperature‐controlled polarized light microscope, and the polymorphism of the solidified fat structures was determined via a temperature‐controlled X‐ray diffractometer. Hardness was measured by a temperature‐controlled Instron mechanical analyzer with a penetration cone. The phase behavior predicted by the DSC and iso‐solid lines did not account for the hardness trends observed, as the microstructure and polymorphism of the fat also played a significant role. The addition of hard fat to a system did not consistently increase the hardness of the fat system. Furthermore, the solution behavior demonstrated by the iso‐solid line diagram did not account for all trends in melting behavior, as both intersolubility and polymorphic changes occurred simultaneously. it was found that variations in hardness can be inferred from structural changes, although the structural level causing variation differs.