The objective of this study was to investigate in depth the non-isothermal crystallization and melting behavior of binary blends of palm oil (PO) with a commercial, multi-component phytosterol ester (PE) mixture. DSC and time-resolved synchrotron X-ray diffraction (XRD) experiments were conducted on blends with a PE concentration from 0 to 100% at intervals of 10% for DSC and 20% for XRD. Based on XRD, two different ordered structures were identified in pure the PEs. The structure designated as PE was truly crystalline and needed a very high degree of supercooling for its nucleation from the melt. The structure designated PE formed without supercooling and showed long-range order with multiple reflections at small angles but only one broad reflection at high angle, typical of liquid crystalline samples. Furthermore, PE had a high tolerance for molecules of different chemical nature. In the PE-PO blends no other ordered structures were formed other than the ones observed in the pure PEs and PO. The peaks in the DSC runs of the PE-PO blends were linked to transitions of the different polymorphic forms. All structural information of the binary blends as a function of concentration and temperature was collected in morphology maps. The binary blends exhibited eutectic characteristics visualized in the morphology maps with a eutectic point at 40% PEs.

Effect of calcium ions and pH on the structure and rheology of carrot-derived suspensionsMoelants, K.R.N.; Cardinaels, R.M.; Greef, de, K.; Daels, E.; Van Buggenhout, S.; Van Loey, A.M.; Moldenaers, P.; Hendrickx, M.E.

The objective of this study was to in depth investigate the 'equilibrium' state morphology and properties of crystals obtained after long-term isothermal crystallization and annealing of palm oil (PO) in the presence of different concentrations of phytosterol esters (PEs). A commercially available mixture of PEs was added to PO (0-100% PEs, 10% increment) and the effect of PE addition was analyzed with differential scanning calorimetry, X-ray diffraction, nuclear magnetic resonance, polarized light microscopy and texture analysis.It was observed that PE addition had a major influence on each level of the crystalline structural hierarchy of PO in the 'equilibrium' state. The PE-PO binary system showed eutectic behavior.In case of a low PE concentration PEs itself did not crystallize but acted as a liquid oil diluting PO, while when added in a high concentration, PEs crystallized separately from PO. From a concentration of 40% PEs next to the β' crystals of PO also PEx crystals were observed in the blends and from a concentration of 80% PEs additionally also the PEy liquid crystals were XRD X-ray diffraction

In literature there is good agreement on the health-promoting effects of phytosterols. However, addition of phytosterol esters (PEs) to lipid (containing food products) may influence its crystallization behavior. This study investigated the crystallization kinetics of palm oil (PO) after addition of PEs in high concentrations (≥10%). The isothermal crystallization of the PE-PO blends was analyzed at a temperature of 20 °C and at a supercooling of 18.7 °C using differential scanning calorimetry and time-resolved synchrotron X-ray diffraction. At increasing PE concentrations, PO crystallization at an isothermal temperature of 20 °C started later and was slower and a smaller amount of crystals were formed. Furthermore, a delay in polymorphic transition from α to β' was observed. When the blends were isothermally crystallized at a supercooling of 18.7 °C, only two of these effects remained: the delay in polymorphic transition and the decrease in crystalline content.

The objective of this study was to investigate the influence of commercially available monoacylglycerol (M), polyglycerol esters (P), and sunflower lecithin (L) on the onset of crystallization of bulk fat as a function of the added concentration. Not only a single type of emulsifier, but also binary and ternary mixtures of M, P, and L were added to the two different "host" fats using a statistically sound mixture design. The obtained mixtures were analyzed for their non-isothermal crystallization behavior by differential scanning calorimetry. If a single type of emulsifier was added, the nucleation was accelerated when adding M or P, while L addition had no significant effect. Furthermore, it was shown that the minimum concentration necessary to provoke a nucleation accelerating effect is lower for P than for M. Antagonistic effects between M and L (and not between P and L) were suggested by the coefficient estimates of the special cubic model.Practical applications: Palm oil (PO) is one of the most consumed vegetable oils in the world because of its unique physical properties. It imparts a very high stability to the b 0 crystal form, yielding relatively small crystals which give a smooth texture to e.g., margarines and shortenings. Because PO is semi-solid at room temperature, it forms an ideal hard stock to be used in trans free food products. However, PO has a slow crystallization rate and an unusually long a-lifetime. These disadvantages can be overcome by the addition of an emulsifier acting as crystallization modifier (e.g., monoacylglycerols and diacylglycerols) [1]. Furthermore, from a nutritional point of view, the saturated fatty acids present in PO [2], are among the factors contributing to cardio-vascular diseases [3]. When using more unsaturated fats as hard stock, the use of additives in order to avoid compromising the functionality of the food product should be further investigated.