Download citation
Download citation
link to html
An improved crystal structure model has been established for the β2 polymorph of the symmetric mono-unsaturated triacylglycerol 1,3-distearoyl-2-oleoylglycerol (SOS) and the equivalent β-V polymorph of Ivory Coast cocoa butter. In addition, the crystal structures of the β2 polymorphs are reported for the triacylglycerols 1,3-dipalmitoyl-2-oleoylglycerol (POP) and 1-palmitoyl-2-oleoyl-3-stearoylglycerol (POS), which are, together with SOS, the major components of cocoa butter, and that of 1-stearoyl-2-oleoyl-3-arachidoylglycerol (SOA). The existence of β2-POS and β2-SOA has not been previously reported in the literature. All structures have been solved from high-resolution laboratory or synchrotron powder diffraction data with the direct-space parallel-tempering program FOX and refined with the Rietveld module of GSAS. All compounds crystallize in similar monoclinic unit cells (Cc) with very long b axes (> 127 Å). The oleic chains are packed together and sandwiched between saturated chain layers, forming acyl-chain three-packs. An analysis of the β2 polymorphs and β1 polymorphs [van Mechelen et al. (2006). Acta Cryst. B62, 1121–1130] shows that they contain the same three-packs and differ only in the symmetry relation between the three-packs. The three-pack build-up provides an explanation of the mechanism of the phase transition that causes the formation of fat bloom on dark chocolate.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768106037086/dr5012sup1.cif
Contains datablocks SOS-B2-XPERT-ENAN2_publ, IV14_B5_280K-ENAN_publ, POP-B2-CH1731-2_ENAN_publ, POS-B2-ENAN_publ, SOA-B2CAP2-XPERT-EXS_publ

rtv

Rietveld powder data file (CIF format) https://doi.org/10.1107/S0108768106037086/dr5012SOS-B2-XPERT-ENAN2_publsup2.rtv
Contains datablock SOS-B2-XPERT-ENAN2_publ

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108768106037086/dr5012SOS-B2-XPERT-ENAN2_publsup3.hkl
Contains datablock SOS-B2-XPERT-ENAN2_publ

rtv

Rietveld powder data file (CIF format) https://doi.org/10.1107/S0108768106037086/dr5012IV14_B5_280K-ENAN_publsup4.rtv
Contains datablock IV14_B5_280K-ENAN_publ

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108768106037086/dr5012IV14_B5_280K-ENAN_publsup5.hkl
Contains datablock IV14_B5_280K-ENAN_publ

rtv

Rietveld powder data file (CIF format) https://doi.org/10.1107/S0108768106037086/dr5012POP-B2-CH1731-2_ENAN_publsup6.rtv
Contains datablock POP-B2-CH1731-2_ENAN_publ

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108768106037086/dr5012POP-B2-CH1731-2_ENAN_publsup7.hkl
Contains datablock POP-B2-CH1731-2_ENAN_publ

rtv

Rietveld powder data file (CIF format) https://doi.org/10.1107/S0108768106037086/dr5012POS-B2-ENAN_publsup8.rtv
Contains datablock POS-B2-ENAN_publ

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108768106037086/dr5012POS-B2_ENAN_publsup9.hkl
Contains datablock POS-B2-ENAN_publ

rtv

Rietveld powder data file (CIF format) https://doi.org/10.1107/S0108768106037086/dr5012SOA-B2CAP2-XPERT-EXS_publsup10.rtv
Contains datablock SOA-B2CAP2-XPERT-EXS_publ

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108768106037086/dr5012SOA-B2CAP2_XPERT-EXS_publsup11.hkl
Contains datablock SOA-B2CAP2-XPERT-EXS_publ

pdf

Portable Document Format (PDF) file https://doi.org/10.1107/S0108768106037086/dr5012sup12.pdf
Supplementary material

CCDC references: 629822; 629823; 629824; 629825; 629826

(IUCr) Crystallography Journals Online - supporting information

Follow Acta Cryst. B
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds