Comparative analysis of graded blends of palm kernel oil, palm kernel stearin and palm stearin.

A comprehensive analysis of graded binary and ternary blends of palm kernel oil (PKO), palm kernel stearin (PKS) and palm stearin (POs) was conducted, including solid fat content, iso-solid diagram, thermal properties, polymorphism and microstructure. Both PKO/POs and PKS/POs blends showed eutectic behavior. While PKO/PKS blends displayed good compatibility and only slightly monotectic effect at high temperature (above 30 °C). POs addition elevated binary phase transition temperature and accelerated the ß crystal formation. PKO/POs and PKS/POs binaries showed ß' polymorphism, ß and ß' polymorphism, and ß polymorphism with different POs additions, while all of PKO/PKS blends showed ß' polymorphism. Ternary blends (PKO/PKS/POs) showed eutectic effects, especially at high temperature (25 and 30 °C). POs addition made ternary blends undergo a polymorphism transformation from ß' to ß. Our findings open up the possibility of non-hydrogenated fat products as well as develop specific food formulations.

Visualized phase behavior of binary blends of coconut oil and palm stearin.

The graded blends of coconut oil (CNO) and palm stearin (POs) phase behavior was studied in the present work, by using pulsed nuclear magnetic resonance (p-NMR), differential scanning calorimetry (DSC) and X-ray scattering (XRD). The kinetic phase diagram which was fitting to DSC data by polynomial equation (R > 0.95), indicated that the CNO-POs binary blends displayed monotectic behavior. The CNO-POs binary system displayed immiscible solid structures (ß and ß' polymorphism) with the addition of POs in the range of 10-60%, beyond which it showed miscible solid structures (ß polymorphism), respectively. Moreover, the presence of POs could elevate the liquid phase transition temperature and transform ß' polymorph into ß. These variations in phase behavior were reflected in the morphology of the binary blends. Our findings not only broaden the application of CNO and POs with novel attributes, but also direct the production of high quality non-hydrogenated fat-containing products.

Influence of indigenous minor components on fat crystal network of fully hydrogenated palm kernel oil and fully hydrogenated coconut oil.

Purification of triglycerides from fully hydrogenated palm kernel oil (FHPKO) and fully hydrogenated coconut oil (FHCNO) was performed by a chromatographic method. Lipid composition, thermal properties, polymorphism, isothermal crystallization behaviour, nanostructure and microstructure of FHPKO, FHPKO-triacylglycerol (TAG), FHCNO and FHCNO-TAG were evaluated. Removal of minor components had no effect on triglycerides composition. However, the presence of the minor components did increase the slip melting point and promote onset of crystallization. Furthermore, the thickness of the nanoscale crystals increased, and polymorphic transformation from ß' to ß occurred in FHPKO after the removal of minor components, and from α to ß' in FHCNO. Sharp changes in the values of the Avrami constant K and exponent n suggested that the presence of minor components changed the crystal growth mechanism. The PLM results indicated that a coarser crystal structure with lower fractal dimension appeared after the removal of minor components from both FHPKO and FHCNO.

Non-triglyceride components modulate the fat crystal network of palm kernel oil and coconut oil.

PKO and CNO are composed of 97-98% triacylglycerols and 2-3% minor non-triglyceride components (FFA, DAG and MAG). Triglycerides were separated from minor components by chromatographic method. The lipid composition, thermal properties, polymorphism, isothermal crystallization behavior, nanostructure and microstructure of PKO, PKO-TAG, CNO and CNO-TAG were evaluated. Removal of minor components had no effect on lipid composition and equilibrium solid fat contents. However, presence of minor components did increase the slip melting point and promoted the onset of crystallization from DSC crystallization profiles. The thickness of the nanoscale crystals increased with no polymorphic transformation after removing the minor components. Crystallization kinetics revealed that minor components decreased crystal growth rate with higher t1/2. Sharp changes in the values of the Avrami constant k and exponent n were observed for all fats around 10°C. Increases in n around 10°C indicated a change from one-dimensional to multi-dimensional growth. From the results of polarized light micrographs, the transformation from the coarser crystal structure to tiny crystal structure occurred in microstructure networks at the action of minor components.

Dispersion behavior and aqueous foams in mixtures of a vesicle-forming surfactant and edible nanoparticles.

In an attempt to prepare ultrastable aqueous foams composed entirely of food-grade ingredients, we describe the foamability and foam stability of aqueous phases containing either calcium carbonate particles (CaCO3), sodium stearoyl lactylate surfactant (SSL), or their mixtures. Techniques including zeta potential measurements, adsorption isotherm determination, contact angles and optical and cryo-scanning electron microscopy are used to probe the interaction between particles and surfactant molecules. Aqueous dispersions of inherently hydrophilic cationic CaCO3 nanoparticles do not foam to any great extent. By contrast, aqueous dispersions of anionic SSL, which forms a lamellar phase/vesicles, foam progressively on increasing the concentration. Despite their foamability being low compared to that of micelle-forming surfactant sodium dodecyl sulfate, they are much more stable to collapse with half-lives (of up to 40 days) of around 2 orders of magnitude higher above the respective aggregation concentrations. We believe that, in addition to surfactant lamellae around bubbles, the bilayers within vesicles contain surfactant chains in a solidlike state yielding indestructible aggregates that jam the aqueous films between bubbles, reducing the drainage rate and both bubble coalescence and gas-transfer between bubbles. In mixtures of particles and surfactant, the adsorption of SSL monomers occurs on particle surfaces, leading to an increase in their hydrophobicity, promoting particle adsorption to bubble surfaces. Ultrastable foams result with half-lives of around an order of magnitude higher again at low concentrations and foams which lose only around 30% of their volume within a year at high concentrations. In the latter case, we evidence a high surface density of discrete surfactant-coated particles at bubble surfaces, rendering them stable to coalescence and disproportionation.