Studies on Granular Crystals Growing in Palm Oil

Ishikawa, Hidetoshi; Mizuguchi, Tsuneo; Kondo, Satoru

doi:10.5650/jos1956.29.235

Cited by 23 publications

(22 citation statements)

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“…In contrast, changes in the percentage of β-form in HT-Fat samples during storage were small. This result was due to the acceleration of polymorph transformation by 1,3-dipalmetoyl 2-oleoyl glycerol (POP) in palm oil, as shown in previous reports (Ishikawa et al, 1980, Watanabe et al, 1992, Miura and Konishi, 2001. The percentage of β-form in samples prepared at 10℃ was higher than that in samples prepared at 5℃ at 14 days; however, the percentages reached similar levels after 28 days.…”

Section: Resultssupporting

confidence: 65%

“…Many studies were conducted to clarify the mechanism of granular crystal formation in palm oil-based products. They have suggested the possibility of a relationship between the transformation to the β-form and the formation of granular crystals in margarine (Ishikawa et al, 1980, Watanabe et al, 1992, Miura and Konishi, 2001, Sato 2001, Walstra et al, 2001, Tanaka et al, 2007, Tanaka et al, 2009. Information on crystallization behavior, including the polymorphic transition, is therefore important for the fat food industry.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Shearing on Crystallization of Palm Oil-Based Fat Blends

Konno¹,

Iwasawa²,

Isogai³

et al. 2012

FSTR

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The effect of shearing on the polymorphic behavior of palm oil-based fat blends with low (LT-Fat) and high (HT-Fat) trans-fatty acid contents during storage was investigated. A shear stress was applied to fat blends at 5℃ or 10℃ by the flat-crush method or after rapid or slow cooling by the syringe-extrusion method. The fat networks were evaluated by cryo-scanning electron microscopy (SEM), polarized light microscopy, and solid fat content measurement, and the polymorphic transition from the β′-form to the β-form under thermal thawing between 5℃ and 20℃ was investigated by X-ray diffraction. Transition to the β-form of LT-Fat with shearing was retarded compared with that without shear. SEM revealed that with shearing, LT-Fat built complex networks involving both fine reticulation and a tight structure, whereas without shearing, the structure was nearly uniform. These results suggest that the non-uniformly network achieved by shearing could suppress the localization of specific triacylglycerides, preventing transformation into the β-form.

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Section: Resultssupporting

confidence: 65%

Section: Introductionmentioning

confidence: 99%

Effect of Shearing on Crystallization of Palm Oil-Based Fat Blends

Konno¹,

Iwasawa²,

Isogai³

et al. 2012

FSTR

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“…The formation of granular crystals has been investigated extensively [1,2]. Ishikawa et al studied the formation of granular crystals in relation to palm oil, which has become a prominent fat source in the margarine and shortening industries due to its favorable physical properties.…”

Section: Introductionmentioning

confidence: 99%

Crystallization behavior of 1,3-dipalmitoyl-2-oleoyl-glycerol and 1-palmitoyl-2,3-dioleoyl-glycerol

Miura¹,

Konishi²

2001

Eur. J. Lipid Sci. Technol.

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A model margarine was stored under a temperature fluctuation cycle of 5-20°C until granular crystals were observed. Using information obtained from the granular crystals, the crystallization behaviors of major triacylglycerols of palm oil, 1,3-dipalmitoyl-2-oleoyl-glycerol (POP), 1-palmitoyl-2,3-dioleoyl-glycerol (POO), and their mixtures were then investigated. It was shown that in the model margarine, the POP content in the granular crystals was higher than in their surrounding materials, and the X-ray diffraction pattern of the granular crystals revealed that they were the most stable polymorph, β. 99% pure POP, POO, and their mixtures were then stored under the above-mentioned temperature cycle. POP was found to form the unstable polymorph, α, when cooled rapidly from the melt. Within 24 hours transformation into the γ polymorph and then into the β polymorph was observed. POO was shown to transform into the β' polymorph from α. When POP and POO were mixed, the β polymorph did not emerge, instead it was shown that POP and POO were both agglomerated in the mixtures, giving rise to the formation of granular crystals.

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“…The influence of shear on palm oil crystallisation and phase transitions has been examined by Mazzanti et al [19,24]. The formation of granular crystals in palm oil-based margarine during storage has been investigated [22,25,26], while its prevention by emulsifier addition was examined [27].…”

Section: Introductionmentioning

confidence: 99%

Thermal and structural behaviour of crude palm oil: Crystallisation at very slow cooling rate

Chong

Kamarudin

Lesieur

et al. 2007

Euro J Lipid Sci & Tech

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Thermal and structural behaviour of crude palm oil: Crystallisation at very slow cooling rateThe crystallisation behaviour of crude palm oil (CPO) has been examined with a new instrument coupling time-resolved synchrotron X-ray diffraction with high-sensitivity differential scanning calorimetry at cooling rates of 0.1 and 0.4 7C/min from melt temperature to -20 7C, in order to determine the triacylglycerol (TAG) organisations formed as a function of temperature and thermal treatment. At slow cooling rate, CPO TAG sequentially crystallise in apparently two different lamellar structures with double-chain length of 41.9 Å and a triple-chain length of 62.8Å stackings of b' type, which are correlated to two main exothermic peaks at 26 and 8 7C, respectively. While a time-dependent slow b'?b irreversible transition is observed even at low temperature, it only affects a few percent of the TAG population. Subsequent heating at 1 7C/min showed no structural rearrangements of the crystalline forms observed before final melting, indicating that the main moiety of the system is close to equilibrium. Crystallisation at 0.4 7C/min has shown the formation of many additional structures, some of which are evanescent. An unexpected finding was the vicinity of the two lines corresponding to the two 2L (bilayered) structures and the isosbestic point located at 4.42 Å. Only careful analysis allowed the separation of both lines, the coexistence of which was related to the epitaxy/eutectic phenomenon, as evidenced by the simultaneous appearance of the 3L (trilayered) stackings at the same time of the second burst of the 2L stacking and the observation of the isosbestic point. The coexistence of b and b' forms even at high temperature demonstrates that the whole system is not in a two-phase domain but rather in a three-phase one (b 1 b' 1 liquid) in which all TAG molecules could not fit into a single b' structure. This is likely related with the granular phase separations observed in margarine.

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Studies on Granular Crystals Growing in Palm Oil

Cited by 23 publications

References 0 publications

Effect of Shearing on Crystallization of Palm Oil-Based Fat Blends

Effect of Shearing on Crystallization of Palm Oil-Based Fat Blends

Crystallization behavior of 1,3-dipalmitoyl-2-oleoyl-glycerol and 1-palmitoyl-2,3-dioleoyl-glycerol

Thermal and structural behaviour of crude palm oil: Crystallisation at very slow cooling rate

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