FT-IR study of polymorphic transformations in SOS, POP, and POS

Yano, Junko; Ueno, Satoru; Sato, Kiyotaka; Arishima, Toshiharu; Sagi, Nobuo; Kaneko, Fumitoshi; Kobayashi, Masamichi

doi:10.1021/j100151a053

Cited by 59 publications

(62 citation statements)

References 12 publications

(19 reference statements)

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“…This suggests that conformational differences exist between the polymorphs of SHs and Si‐SHs around the carbonyl bond, which is resolvable in Raman spectra. Similar observations were reported in the case of cocoa butter TAGs , StOSt (by conventional IR) and tristearin . However, Sprunt et al reported two bands for the β form of StOSt TAG.…”

Section: Resultssupporting

confidence: 78%

Crystallization and polymorphic behavior of shea stearin and the effect of removal of polar components

Ray

Smith²,

Bhaggan³

et al. 2013

Euro J Lipid Sci & Tech

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The crystallization of shea stearin was investigated both before and after pre‐treatment with silica to remove a small amount (0.7 wt%) of diacylglycerols (DAGs) and oxidized material. NMR (for solid fat content), X‐ray diffraction (XRD), polarized light microscopy, confocal Raman microscopy, and non‐isothermal, isothermal and “stop‐and‐return” differential scanning calorimetry (DSC) techniques were used. Four major polymorphs previously found with 1,3‐distearoyl‐2‐oleoyl‐sn‐glycerol (StOSt) were detected: α, γ, β′, and β; whilst evidence for a further (δ) polymorph was found by DSC and possibly XRD but not Raman spectroscopy. Isothermal crystallization of shea stearins by DSC at 20°C produced α and δ forms within 5 min which then transformed to γ. Microscope images showed that after 1 day these had transformed into β′ with a few crystals of β, with further conversion to β after one week. Silica treated samples showed a faster initial crystallization, with faster transformation or direct crystallization into δ and then γ and β′ forms. Non‐isothermal DSC also showed a faster transformation into γ from α on the subsequent remelt. However, further transformation into β appeared to occur at reasonably similar rates for both types, suggesting that DAGs have less influence on this transformation and may be excluded from higher forms. Practical applications: This paper has two main practical applications: (i) Provides knowledge and understanding of the crystallization and polymorphic behavior of commercial shea stearin, which is a widely used fat in the confectionery, cosmetic, and pharmaceutical industries. (ii) The presence of small amounts of DAGs significantly delays the crystallization process of shea stearin, particularly of the lower polymorphs.

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Section: Resultssupporting

confidence: 78%

Crystallization and polymorphic behavior of shea stearin and the effect of removal of polar components

Ray

Smith²,

Bhaggan³

et al. 2013

Euro J Lipid Sci & Tech

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“…This indicates that the increase in the SLS concentration may have prohibited the occurrence of the β′ form in the SOS/SLS mixture during α-melt mediation. Figure 5 shows results of the RA-XRD study of the α-melt-mediated transformation of SOS, SOS/SLS mixtures (75:25 and 70: 30), and SLS when the α form was rapidly heated from 10 to 36°C. In the 75:25 SOS/SLS mixture, the β 2 form of the SOS fraction crystallized immediately, and the SLS fraction melted together with a small amount of the SOS fraction.…”

Section: Resultsmentioning

confidence: 99%

“…It is important to understand the physical properties of the binary mixture phases of SOS and SLS, since this mixing behavior is closely related to fat blending in fat technology and the separation of fats and oils in industrial crystallization processes. The thermal and structural properties of SOS (29)(30)(31) and SLS (32) are summarized in Table 1. SOS has five polymorphic forms-α, γ, β′, and two β forms-and SLS has two forms-α and γ.…”

mentioning

confidence: 99%

Binary phase behavior of 1,3‐distearoyl‐2‐oleoyl‐sn‐glycerol (SOS) and 1,3‐distearoyl‐2‐linoleoyl‐sn‐glycerol (SLS)

Takeuchi

Ueno

Flöter

et al. 2002

J Americ Oil Chem Soc

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The binary phase behavior of SOS (1,3-distearoyl-2-oleoyl-sn-glycerol) and SLS (1,3-distearoyl-2-linoleoyl-sn-glycerol) was examined by using DSC and conventional and synchrotron radiation X-ray diffraction. The solidsolution phases were observed in the metastable α and γ forms in all concentration ranges. Results indicated that the miscible γ form did not transform to the β′ form when the mixtures were subjected to simple cooling from a high-temperature liquid to a low-temperature solid phase. However, an α-melt-mediated transformation into β′ and β 2 resulted in the formation of immiscible phases in concentration ranges of SLS below 30%. By contrast, at SLS concentration ranges above 30%, the α-meltmediated transformation caused crystallization of only the γ form, and β′ and β 2 crystals did not appear. These results show that the specific interactions between SOS and SLS are operative in the phase behavior of the mixture states of SOS and SLS.The phase behavior of TAG mixtures is one of the major factors that determines the macroscopic properties of fat products, such as mouthfeel, appearance, and rheology, together with fat polymorphism, crystal size, morphology, and crystal network formation (1-8).Real fat systems of both vegetable and animal origin are multicomponent systems containing different kinds of FA moieties. The complex features of real fat systems are due to fat polymorphism as well as the mixing behavior of different TAG. The physical analysis of real fat systems usually starts with understanding the individual TAG molecules and subsequently moves on to understanding the mixed systems. The best approach for the latter task usually starts with studying binary mixture systems of different TAG and extends to ternary and multicomponent mixture systems. Therefore, many studies of binary phase behavior have been performed for different combinations of TAG mixtures (9-15).In the phase behavior of binary mixture systems, three typical phases can occur: a solid-solution phase, a eutectic phase, and molecular compound formation. The general tendency in the relationship between molecular interactions and phase behavior may be summarized as follows: (i) The two components (A and B) can exchange places with one another in the crystal lattice in all concentration ratios (solid-solution phase); (ii) no solubilities will exist in the lattices of crystals A and B, respectively (eutectic phase); and (iii) highly specific interactions can give rise to the formation of molecular compounds. In the particular case of the mixture of tristearin/tripalmitin (SSS/PPP) (16,17), metastable α and β′ forms were shown to exhibit continuous solid solutions, yet a eutectic nature was revealed in the most stable β form. For PPP/1,3-dipalmitoyl-2-oleoyl-sn-glycerol (POP) mixtures (18,19), eutectic phases were observed in the metastable α and β′ forms and in the most stable β form as well. Recent studies on phase behavior have revealed various types of binary mixtures of TAG that form molecular compounds: 1,3-distearoyl-2-oleoyl-sn...

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“…Figure 16 clearly indicates that the thermal factors are becoming higher 7) 114.4 (6) 114.2(6) C(6)-C(7)-C (8) 113.0(6) 113.8(6) C(7)-C(8)-C (9) 113.5 (6) 113.3(6) C(8)-C(9)-C (10) 114.0(6) 113.7(6) C(9)-C(10)-C (11) 113.6(6) 113.0(6) C(10)-C(11)-C (12) 114.4 (7) 112.9(7) C(11)-C(12)-C (13) 113.2 (7) 113.0(8) C(12)-C(13)-C (14) 127 179 (4) 176 (4) starting from the 15th carbon atom toward the methyl terminal. Specially large thermal factors around the methyl terminal may reflect the conformational disorders observed in Raman spectroscopy.…”

Section: Changes In Chainmentioning

confidence: 97%

“…In the field of glycerides, it has been also clarified that polymorphism of glycerides becomes more complex by introduction of cis-unsaturated chains. [6][7][8] However, detailed structures of cis-unsaturated acyl chains in these systems are still unclear.…”

Section: Introductionmentioning

confidence: 99%

Mechanism of the γ → α and γ1 → α1 Reversible Solid-State Phase Transitions of Erucic Acid

Kaneko¹,

Yamazaki²,

Kobayashi³

et al. 1996

J. Phys. Chem.

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Two reversible solid-state phase transitions of erucic acid (cis-13-docosenoic acid), the γ f R and γ1 f R1 phase transitions, have been followed by vibrational spectroscopy (IR and Raman) and X-ray diffraction. The crystal structure analyses of the higher temperature phases, R and R1, have been performed. The symmetry of crystal lattices remains unchanged during the both transitions, i.e., the γ and R phases belong to a monoclinic system (P2 1 /a) and the γ1 and R1 phases belong to a triclinic one (P1 h). At the γ f R transition point, the subcell structure of the methyl-terminal chains is reconstructed, accompanying a large conformational change of cis-olefin groups. On the γ1 f R1 transition, the inclination manner of hydrocarbon chains changes, while there are no significant changes in the subcell structure and the conformation of cis-olefin groups. The conformational disorder at methyl terminals increases continuously for the γ1 f R1 transition, contrary to an abrupt occurrence at the γ f R transition. The unit cell volume also increases gradually in the γ1 and R1 phases and shows no prominent changes at the γ1 f R1 transition, while a stepwise increase takes place at the γ f R transition. The important factors for transition behaviors are discussed on the basis of the crystal structures.

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FT-IR study of polymorphic transformations in SOS, POP, and POS

Cited by 59 publications

References 12 publications

Crystallization and polymorphic behavior of shea stearin and the effect of removal of polar components

Crystallization and polymorphic behavior of shea stearin and the effect of removal of polar components

Binary phase behavior of 1,3‐distearoyl‐2‐oleoyl‐sn‐glycerol (SOS) and 1,3‐distearoyl‐2‐linoleoyl‐sn‐glycerol (SLS)

Mechanism of the γ → α and γ1 → α1 Reversible Solid-State Phase Transitions of Erucic Acid

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