The Polymorphism of Saturated 1,3-Diglycerides

Baur, Fred J.; Jackson, F.; Kolp, Don G.; Lutton, Évelyne

doi:10.1021/ja01178a027

Cited by 35 publications

(20 citation statements)

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“…No polymorphic transformation from /?, to p, was noted even at a relatively rapid heating rate (20°C min-'). The melting point of 70.0"C may be compared to previously reported literature values of 71.8"C (Baur et al 1949) and 715°C (Howe and Malkin 1951). The p,-polymorph melted with a heat of fusion of 109.4 kJ mol-'.…”

Section: Dscmentioning

confidence: 81%

The polymorphism of diglycerides

et al. 1992

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Abstract:The polymorphism of 1,3-dipalmitin, 1.2-dipalmitoyl-sn-glycerol, 1.2-dipalmitoyl-ruc-glycerol has been examined by X-ray diffraction, IR spectroscopy and Raman spectroscopy and differential scanning calorimetry. The respective spectra and thermographs are presented for these polymorphs. Optically active 1,2-diglycerides exhibit very different thermal behaviour from the optically inactive 1,2-diglycerides. A novel HPLC system was devised for the separation of the diglycerides.

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Section: Dscmentioning

confidence: 81%

The polymorphism of diglycerides

et al. 1992

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“…This suggests that most DAG components that crystallized at 3°C are 1,3-DAG. According to previous studies on purified DAG, In general, 1,3-DAG have higher melting points than the 1,2-DAG with the same fatty acid compositions [30][31][32][33][34][35], and the 1,3-DAG tend to crystallize much faster than the 1,2-DAG out of solution This is probably owing to the conformation of DAG molecules with respect to the lamellar plane. 1,3-DAG form a V-shaped structure with the two chains extending in opposite directions and may exhibit stronger hydrogen bonding of the hydroxyl group and hydrophobic bonding among fatty acid chains, as shown in Fig.…”

Section: Dsc and Microscopy Analyses Of Crystallization Behaviors Of mentioning

confidence: 99%

Crystallization Behavior of Diacylglycerol‐Rich Oils Produced from Rapeseed Oil

Saitou

Mitsui

Shimizu

et al. 2012

J Americ Oil Chem Soc

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We examined the crystallization behavior of high-melting fractions in liquid oil containing high concentrations of diacylglycerols (DAG [80%) (hereafter referred to as DAG-rich oil). By differential scanning calorimetry and optical microscopy at moderate cooling rates, crystallization in the DAG-rich oil was detected at around 6°C. It was found that the crystallization extent increased with decreasing temperatures of crystallization below 0°C. A gas chromatographic analysis was performed on the crystallized fractions, which were separated by filtration at different periods of isothermal crystallization at 3°C. The results indicated that at earlier crystallization periods, the concentrations of 1,3-disaturated DAG such as palmitic and stearic acid moieties (15 min) and 1,3-saturated-unsaturated mixed-acid DAG including oleic acid, palmitic, and stearic acid moieties (15 min-3 h) were predominant. However, the concentrations of 1,3-diunsaturated DAG including oleic acid moiety increased after a crystallization period of 6 h. To clarify the sequential crystallization process of DAG, we examined the binary mixing behavior of principal DAG components occurring in the rapeseed-based DAG-rich oil. It was evident that 1,3-disaturated DAG, 1,3-saturated-unsaturated mixedacid DAG, and 1,3-diunsaturated DAG exhibited immiscible behavior. From these data, basic information on the precipitation processes in DAG-rich oils at chilled temperatures was obtained.

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“…In the crystallization process, crystals were probably in the ~3-a polymorphic form due to the recrystallization from the (13), t,3-dipalmitin has a l]-a polymorph when it is crystallized from the melt. It is also probable that crystals are in the I]-b form due to the higher temperature (room temperature) used in the crystallization process.…”

Section: Resultsmentioning

confidence: 99%

Composition of crystals of palm olein formed at room temperature

Swe

Man

Ghazali

1995

J Americ Oil Chem Soc

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The composition of purified palm olein crystals formed at room temperature (25°C) was identified in this study. Two peaks were obtained when the crystals were analyzed by reverse-phase high-performance liquid chromatography (RP-HPLC). The retention times of these peaks suggested that they were not triglycerides. Gas-liquid chromatography of fatty acid methyl ester analysis of the crystals showed the presence of C16, C18:0, and C18:1 fatty acids. Further analysis by gas-liquid chromatography of carbon number, after collecting the fractions from RP-HPLC, concluded that the major peak A was 1,3dipalmito-glycerol. The minor peak B was tentatively identified as 1-pa[mito-3-stearo-glycerol and/or 1-palmito-3-oleo-glycerol due to unavailability of respective standard glycerides. The differential scanning calorimetry thermogram of the crystals show that A and B were indeed the high melting glycerides, with melting and crystallization points of 70.4 and 53.8°C, respectively. JAOCS 72, 343-347 (1995).KEY WORDS: Crystals, 1,3-dipalmito-glycerol, HMGs, 1-palmito-3-oteo-glycerol, 1-palmito-3-stearo-glycerol, palm olein. L,I.I z z o o. z m z 9 I J MIN FIG. 3. Reverse-phase high-performance liquid chromatography chromatogram of purified palm olein crystals. See Figure 1 for abbreviation.

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The Polymorphism of Saturated 1,3-Diglycerides

Cited by 35 publications

References 0 publications

The polymorphism of diglycerides

The polymorphism of diglycerides

Crystallization Behavior of Diacylglycerol‐Rich Oils Produced from Rapeseed Oil

Composition of crystals of palm olein formed at room temperature

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