Thermal and Structural Behavior of Milk Fat

Thermal and Structural Behavior of Milk Fat

“…10). It is worth noting that, contrary to previous studies (29) except for the first and last species formed on crystallization and remaining on melting, respectively, no clear attribution of the lateral packing was possible because of the large number of varieties observed at small angles. In this respect, the first two species formed upon crystallization were 2L and likely alpha (Fig.…”

“…Fast cooling of cream and AMF resulted in the formation of unstable forms the crystallization of which likely obeys homogeneous nucleation (29). Thus, no drastic difference is expected in the thermal and structural behavior of the bulk and dispersed systems when quenched.…”

“…From our data, it is not possible to demonstrate that the nucleation of crystallization in cream globules is a heterogeneous process, although, the much slower crystallization behavior observed by DSC for cream is rather more easily explained by such a hypothesis rather than related to the size distribution of the globules. It is worth noting that the size distribution of fat globules in this study is equivalent to that studied in (29). Assuming that the cream crystallization is heterogeneous, it likely triggered a water-fat globule interface by the molecules that coat the droplet such as proteins and lipids.…”

“…Concentrated creams (fat content ≥40% (wt/wt)), resulting from industrial skimming of fresh whole milks collected in Brittany in May 1998 (identical to that analyzed in (29)) and July 2000, were obtained from two French dairy plants, Laïta and Lactalis. The extraction protocol of AMF from cream is detailed elsewhere (34).…”

“…The examination of cream polymorphism is especially difficult since (i) both small and wide angles should be considered at the same time and compared to determine the evolution of each of the species as a function of temperature, (ii) the X-ray diffracted by each of the species is reduced to the proportion of the fraction considered, (iii) the whole X-ray diffraction signal is largely absorbed by the surrounding water and its solutes, and (iv) the peak broadening results from the crystallization constraints in dispersed systems (29). Then, polymorphic evolution as a function of time and temperature of cream fat requires the use of the synchrotron X-ray diffraction facilities and the consideration of the possible coexistence of different species in cream as shown in milk fat.…”