Differential scanning calorimetry analysis

To perform thermal analysis, Perkin Elmer’s (Shelton, Connecticut, USA) differential scanning calorimetry (DSC) 4000 equipped with a standard single-furnace was used. A known protocol was used [22], which includes using a temperature range of 25–300 °C (this range can cover all thermal events associated with lactose) while increasing the temperature at a rate of 10 °C/min. All samples were run under N₂ gas, which allows for the samples to be purged, at a rate of 50 mL/min. Each of the samples was accurately weighed, where the mass ranged from 4 to 5 mg per sample on aluminum pans and sealed with an aluminum cap. Calibration was completed through the use of indium and zinc prior to any DSC run. All DSC traces were analyzed in terms of melting point and enthalpy with the accompanied Pyris Series software.