Published online by Cambridge University Press: 01 June 2009
The effects of varying salt contents and cream-cooling treatments on thermograms of the resultant butters were determined by differential scanning calorimetry (DSC). A procedure is described for loading the calorimeter without erasing the thermal history of the sample. Unsalted butter had only one melting transition associated with the aqueous phase, at −0·5 °C. Salted butters had two such transitions. One occurred at a constant −22 °C and corresponded to melting of a NaCl–water eutectic mixture. The other varied with the salt content and probably corresponds to melting of the ice in a NaCl solution. Slow-cooling treatment of cream resulted in butter thermograms similar at 10 and 25 °C to those from the Alnarp treatment, but differed between 22 and 25 °C. Shock-cooling resulted in higher amounts of crystallization than the other 2 treatments. The DSC was shown to be useful in following the effects of cream treatment upon the melting characteristics of the resulting butter.