Melting behavior of blends of milk fat with hydrogenated coconut and cottonseed oils

The melting behavior of milk fat, hydrogenated coconut and cottonseed oils, and blends of these oils was examined by nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). Solid fat profiles showed that the solid fat contents (SFC) of all blends were close to the weighted aver ages of the oil components at temperatures below 15 degreesC. However, from 15 to 25 degreesC, blends of milk fat with hydrogenated coconut oils exhib ited SFC lower than those of the weighted averages of the oil components by up to 10% less solid fat, Also from 25 to 35 degreesC, in blends of milk f at with hydrogenated cottonseed oils, the SFC were lower than the weighted averages of the original fats. DSC measurements gave higher SFC values than those by NMR. DSC analysis showed that the temperatures of crystallization peaks were lower than those of melting peaks for milk fat, hydrogenated co conut oil, and their blends, indicating that there was considerable hystere sis between the melting and cooling curves. The absence of strong eutectic effects in these blends suggested that blends of milk fat with these hydrog enated vegetable oils had compatible polymorphs in their solid phases. This allowed prediction of melting ng behavior of mi Ik-fat blends with the abo ve oils by simple arithmetic when the SFC of the individual oils and their interaction effects were considered.