Miura, Yamamoto, and Konishi (2002) observed granular crystals
in palm oil with added MP. TAG analysis of the granular crystals and
their surroundings revealed that agglomeration of higher melting
point TAGs (especially POP) around the MP had occurred. These findings
are in line with the above assumption that MP induces a fractional
crystallization.
When 8% MP was added to PO, a high-melting fraction of the PO
TAGs was triggered by the MP, followed by crystallization of lowermelting
TAGs (fractional crystallization). However, at a lower concentration
of 2 and 4% MP, the MP crystallized at a lower temperature
and its crystallization peak overlapped with the crystallization of
high-melting TAGs. The lower-melting TAGs of PO then crystallized at
a lower temperature (Fig. 5). In the stop-and-return melting profiles
shown in Fig. 6B and C, the melting of the MP and the high-melting
TAGs appeared as a shoulder of the melting peak of the low-melting
PO TAGs. Similar to the blend containing 8% MP, a polymorphic transition
of the α crystals took place.