Effects of Wax Concentration and Carbon Chain Length on Structural Modifications of Fat Crystals

Natural waxes are cost-effective and potential fat crystallization modifier, whereas there are limited information about their implementation on solid triacylglycerols (TAGs) oil. Herein, we investigated the effects of two natural waxes with different concentrations (2, 4, 6, 8 wt%) and carbon chains on the crystal growth and structure of palm kernel stearin (PKS85). Candelilla wax (CLW) could significantly accelerate PKS85 crystallization process. Both two waxes could induce a new hydrocarbon chain with the distances of 3.70 and 4.15A during TAGs crystallization. More particularly, X-ray diffraction (XRD) indicated that PKS85 combined with CLW showed similar lamellar thickness (d001) and crystal domain size () with pure PKS85, whereas PKS85 containing rice bran wax (RW) were 1.7-1.8 and 1.5-1.8 folds for d001 and , respectively. This corresponded to the carbon chain length of CLW and RW, which were double and quadruple PKS85. Further, these variations were reflected on the crystal microstructures of PKS85 with CLW or RW: the former showed small homogeneous crystals, while the latter displayed large rod-like layer crystals. Additionally, the firmness significantly increased when adding CLW and RW, which possibly attributed to the fact that the waxes become the backbone of the crystal “fence”. Our findings give a clear insight into the interaction between TAGs and waxes molecules in the crystallization, which could guide natural waxes utilization in the fat modification.