scholarly journals Structures of mono-unsaturated triacylglycerols. II. The β2 polymorph

2006 ◽  
Vol 62 (6) ◽  
pp. 1131-1138 ◽  
Author(s):  
Jan B. van Mechelen ◽  
Rene Peschar ◽  
Henk Schenk
Keyword(s):  
Cocoa Butter ◽  
Acyl Chain ◽  
Parallel Tempering ◽  
Structure Model ◽  
Symmetry Relation ◽  
Fat Bloom ◽  
Acta Cryst ◽  
Synchrotron Powder Diffraction ◽  
Unit Cells ◽  
Saturated Chain

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.

scholarly journals Structures of mono-unsaturated triacylglycerols. I. The β1 polymorph

2006 ◽  
Vol 62 (6) ◽  
pp. 1121-1130 ◽  
Author(s):  
Jan B. van Mechelen ◽  
Rene Peschar ◽  
Henk Schenk
Keyword(s):  
Structural Model ◽  
Least Square ◽  
Brute Force ◽  
Fat Bloom ◽  
Acta Cryst ◽  
Synchrotron Powder Diffraction ◽  
Bloom Formation ◽  
Saturated Chain ◽  
Pure Compounds ◽  
Acyl Chains

The crystal structures of the β1 polymorphs of mono-unsaturated triacylglycerols have been solved from high-resolution laboratory and synchrotron powder diffraction data for five pure compounds, the 1,3-dimyristoyl-2-oleoylglycerol (β1-MOM), 1,3-dipalmitoyl-2-oleoylglycerol (β1-POP), 1,3-distearoyl-2-oleoylglycerol (β1-SOS), 1-palmitoyl-2-oleoyl-3-stearoylglycerol (β1-POS), 1-stearoyl-2-oleoyl-3-arachidoylglycerol (β1-SOA) and three mixtures: the co-crystallized 1:1 molar mixture of SOS and POP [β1-SOS/POP (1:1)] and two cocoa butters from Bahia and Ivory Coast, both in their β-VI (= β1) polymorph. All eight β1 structures crystallized in the space group (P21/n) and have two short cell axes (5.44–5.46 and 8.18–8.22 Å), as well as a very long b axis (112–135 Å). The dominant-zone problem in the indexing of the powder patterns was solved with the special brute-force indexing routine LSQDETC from the POWSIM program. Structures were solved using the direct-space parallel-tempering method FOX and refined with GSAS. Along the b axis, alternations of inversion-centre-related `three-packs' can be discerned. Each `three-pack' has a central oleic zone, with oleic acyl chains of the molecules being packed together, that is sandwiched between two saturated-chain zones. The conformation of the triacylglycerol molecules is relatively `flat' because the least-square planes through the saturated chains and those through the saturated parts of the olein chain are parallel. The solution of the β1 structures is a step forward towards understanding the mechanism of fat-bloom formation in dark chocolate and has led to a reexamination of the β2 structural model [see van Mechelen et al. (2006). Acta Cryst. B62, 1131–1138].

The crystal structure of Na(NH4)Mo3O10·H2O

2017 ◽  
Vol 32 (2) ◽  
pp. 140-147 ◽  
Author(s):  
Joel W. Reid ◽  
James A. Kaduk ◽  
Jeremy A. Olson
Keyword(s):  
Crystal Structure ◽  
Density Functional Theory ◽  
Rietveld Refinement ◽  
Software Package ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Parallel Tempering ◽  
Powder Diffraction Data ◽  
Functional Theory ◽  
Synchrotron Powder Diffraction

The crystal structure of Na(NH4)Mo3O10·H2O has been solved by parallel tempering using the FOX software package with synchrotron powder diffraction data obtained from beamline 08B1-1 at the Canadian Light Source. Rietveld refinement, performed with the software package GSAS, yielded orthorhombic lattice parameters of a = 13.549 82(10), b = 7.618 50(6), and c = 9.302 74(7) Å (Z = 4, space group Pnma). The structure is composed of molybdate chains running parallel to the b-axis. The Rietveld refinement results were compared with density functional theory calculations performed with CRYSTAL14, and show excellent agreement with the calculated structure.

Acyl chain that matters: introducing sn-2 acyl chain preference to a phospholipase D by protein engineering

2019 ◽  
Vol 32 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Jasmina Damnjanović ◽  
Hideo Nakano ◽  
Yugo Iwasaki
Keyword(s):  
Protein Engineering ◽  
Phospholipase D ◽  
Enzymatic Synthesis ◽  
Acyl Chain ◽  
Saturation Mutagenesis ◽  
Structure Model ◽  
Streptomyces Antibioticus ◽  
In The Wild ◽  
Structured Phospholipids ◽  
Experimental Findings

AbstractPhospholipase D (PLD) is an enzyme widely used for enzymatic synthesis of structured phospholipids (PLs) with modified head groups. These PLs are mainly used as food supplements and liposome ingredients. Still, there is a need for an enzyme that discriminates between PLs and lysoPLs, for specific detection of lysoPLs in various specimens and enzymatic synthesis of certain PLs from a mixed substrate. To meet this demand, we aimed at altering sn-2 acyl chain recognition of a PLD, leading to a variant enzyme preferably reacting on lysoPLs, by protein engineering. Based on the crystal structure of Streptomyces antibioticus PLD, W166 was targeted for saturation mutagenesis due to its strong interaction with the sn-2 acyl chain of the PL. Screening result pointed at W166R and W166K PLDs to selectively react on lysophosphatidylcholine (lysoPC), while not on PC. These variants showed a negative correlation between activity and sn-2 chain length of PL substrates. This behavior was not observed in the wild-type (WT)-PLD. Kinetic analysis revealed that the W166R and W166K variants have 7–10 times higher preference to lysoPC compared to the WT-PLD. Additionally, W166R PLD showed detectable activity toward glycero-3-phosphocholine, unlike the WT-PLD. Applicability of the lysoPC-preferring PLD was demonstrated by detection of lysoPC in the mixed PC/lysoPC sample and by the synthesis of cyclic phosphatidic acid. Structure model analyses supported the experimental findings and provided a basis for the structure model-based hypothesis on the observed behavior of the enzymes.

Complete crystal structure of decafluorocyclohex-1-ene at 4.2 K from original neutron diffraction data

2014 ◽  
Vol 70 (2) ◽  
pp. 395-397
Author(s):  
Leonid A. Solovyov ◽  
Alexandr S. Fedorov ◽  
Aleksandr A. Kuzubov
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Molecular Orientation ◽  
State Energy ◽  
Structure Model ◽  
Perfect Agreement ◽  
Acta Cryst ◽  
Difference Density ◽  
Density Analysis ◽  
The Difference

The crystal structure model of decafluorocyclohex-1-ene at 4.2 K derived from simulated powder diffraction data and solid-state energy minimization [Smrčoket al.(2013).Acta Cryst.B69, 395–404] is found to be incomplete. In this study it is completed by an additional alternative molecular orientation revealed from the difference density analysis and direct space search. The structure is refined by the derivative difference method in the rigid-body approximation leading to perfect agreement between observed and calculated neutron powder patterns.

Delaying fat bloom formation in dark chocolate by adding sorbitan monostearate or cocoa butter stearin

2018 ◽  
Vol 256 ◽  
pp. 390-396 ◽  
Author(s):  
Monise Helen Masuchi Buscato ◽  
Larissa Miho Hara ◽  
Élida Castilho Bonomi ◽  
Guilherme de Andrade Calligaris ◽  
Lisandro Pavie Cardoso ◽  
...  
Keyword(s):  
Cocoa Butter ◽  
Sorbitan Monostearate ◽  
Dark Chocolate ◽  
Fat Bloom ◽  
Bloom Formation

scholarly journals Structures of Na9[SO4]4 X·2H2O2, where X = Cl or Br, in which the halide anions orchestrate extended orientation sequences of H2O2 solvate molecules

2005 ◽  
Vol 61 (6) ◽  
pp. 663-668 ◽  
Author(s):  
Robin Gavin Pritchard ◽  
Zubeda Begum ◽  
Yuf Fai Lau ◽  
Jonothan Austin
Keyword(s):  
Hydrogen Peroxide ◽  
Coordination Shell ◽  
Considerable Influence ◽  
Acta Cryst ◽  
Reflection Data ◽  
Sodium Cations ◽  
Halide Anions ◽  
Unit Cells

Detailed structures of nonasodium tetrakis(sulfate) chloride diperhydrate, Na9[SO4]4Cl·2H2O2, and its novel bromide analogue are compared. Hydrogen peroxide could not be resolved in a previously reported Na9[SO4]4Cl·2H2O2 substructure [tetragonal, P4/mnc; Adams et al. (1978), J. Chem. Soc. Chem. Commun. p. 288; Adams & Pritchard (1978), Acta Cryst. B34, 1428–1432]. However, on lowering the symmetry to P4/n, and using reflection data based on full unit-cells, the H2O2 solvate can be clearly seen. Although H2O2 molecules are not directly bonded to the halide anions, they exert considerable influence on the eight sodium cations that constitute each halide's coordination shell so that H2O2 ordering can be linked to halide dimensions.

scholarly journals Stability of Chocolates Enriched with Cocoa Shell during Storage

Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 3
Author(s):  
Veronika Barišić ◽  
Ante Lončarić ◽  
Ivana Flanjak ◽  
Antun Jozinović ◽  
Stela Jokić ◽  
...  
Keyword(s):  
Cocoa Butter ◽  
Fat Bloom ◽  
Cocoa Shell ◽  
The Stability

The stability of chocolate is mainly influenced by cocoa butter re-crystallization during storage, shown through fat bloom (appearance of white layers of cocoa butter on

scholarly journals Pre-Crystallization of Nougat by Seeding with Cocoa Butter Crystals Enhances the Bloom Stability of Nougat Pralines

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1056
Author(s):  
Birgit Böhme ◽  
Annika Bickhardt ◽  
Harald Rohm
Keyword(s):  
Thermal Properties ◽  
Cocoa Butter ◽  
Oil Content ◽  
Hazelnut Oil ◽  
Fat Bloom ◽  
Oil Migration ◽  
Technological Tool ◽  
Lower Temperature ◽  
Different Origins ◽  
Outstanding Quality

Fat bloom is an outstanding quality defect especially in filled chocolate, which usually comprises oils of different origins and with different physical properties. Dark chocolate pralines filled with nougat contain a significant amount of hazelnut oil in their center and have been reported as being notably susceptible to oil migration. The current study was designed to test the assumption that a targeted crystallization of nougat with cocoa butter seed crystals is an appropriate technological tool to reduce filling oil transfer to the outside of the praline and, hence, to counteract chocolate shell weakening and the development of fat bloom. For this purpose, the hardness of nougat/chocolate layer models and the thermal properties of chocolate on top of nougat were analyzed during storage at 23 °C for up to 84 days. Pronounced differences between layer models with seeded nougat and with control nougat that was traditionally tempered were observed. The facts that chocolate hardness increased rather than decreased during storage, that the cocoa butter melting peak was shifted towards a lower temperature, and that the hazelnut oil content in the chocolate was reduced can be taken as explicit indicators for the contribution of seeded nougat to the fat bloom stability of filled chocolate.

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