It is interesting that we still observe two peaks in the DSC cooling runs, showing that a rotator phase is adopted prior to crystallization of C30d. Previously, the role of the rotator phase upon homogeneous nucleation was not clear . Rotator phases were observed in droplets of odd n-alkanes between 15 and 19 carbons, and both the liquid-to-rotator and rotator-to-crystal transition temperatures were decreased notably. However, the liquid-to-rotator transition temperature was affected more strongly, reducing the interval in which the rotator phase could be observed . For odd and even nalkanes between C20 and C32, rotator phases were observed during heating, but not upon cooling . Consequently, it was argued that these n-alkanes crystallize directly, without transitioning through a rotator phase, upon homogeneous crystallization. It has also been found that the interface between n-alkane and the confining material (e.g. surfactant or polymer microcapsules) can induce surface heterogeneous nucleation . In such systems the freezing temperatures are not reduced as much as in the case of homogeneous nucleation, and rotator phases occur if the surfactant hydrocarbon tails are of similar length as the alkane . Our measurements show a rotator phase even during cooling, as well as significant undercoolings for both the liquid-to-rotator and rotator-to-crystal transition. It seems reasonable that the lipid acyl tails can induce surface heterogeneous nucleation similar to the surfactants mentioned above. Weidinger et al. argue that such nucleation does not necessarily have to result in smaller undercoolings, since the number of molecules exposed to the surface, and therefore available for nucleation, is comparatively small . Possibly, the liquid-to-rotator transition of C30d in our samples is indeed heterogeneous, and therefore still visible in the DSC scans. Only the rotatorto-crystal transition might be truly homogeneous, similar to mixtures of C18/C19 investigated by Jiang et al. or observations by Kovacik et al. on C16 in surfactant emulsion droplets .