Effect of Lactose Monolaurate and High Intensity Ultrasound on Crystallization Behavior of Anhydrous Milk Fat

Crystallization behavior of anhydrous milk fat (AMF) was studied with the addition of 0.025 and 0.05 % lactose monolaurate (LML). The crystallization behavior was studied at low (Delta T = 3 A degrees C) and high supercooling (Delta T = 6 A degrees C). Polarized light microscopy and laser turbidimetry indicated a delay in crystallization on addition of 0.025 % and 0.05 % LML or Tween 20 to AMF. High intensity ultrasound (HIU) was applied to AMF samples with 0.05 % LML and lower supercooling (T (c) = 31 A degrees C; Delta T = 3 A degrees C). HIU application in AMF and AMF + 0.05 % LML induced crystallization (p < 0.05) changing the induction time (tau) at 31 A degrees C from 34.20 +/- A 1.67 min (AMF) and 47.07 +/- A 1.27 min (AMF + 0.05 % LML) to 23.23 +/- A 3.26 min (AMF) and 25.00 +/- A 0.87 min (AMF + 0.05 % LML). Melting enthalpies (Delta H) of AMF were significantly higher (p < 0.05) than the ones observed for AMF + 0.05 % LML when crystallized without HIU, while enthalpy values increased significantly in AMF + 0.05 % LML samples when crystallized with HIU reaching similar values to the ones obtained for AMF without LML. The viscosity of AMF significantly decreased (p < 0.05) on addition of 0.05 % LML and significantly increased on HIU application.