Effect of monoglyceride on crystallization behavior and physical properties of cottonseed oil stearin

Slow crystallization-rate, low SFC and nonuniform mushy texture at ambient temperature hinder the application of cottonseed oil stearin (COS) in plastic fat products. Adding emulsifiers is usually used to overcome these drawbacks by modifying the crystallization of COS. In this study, different levels of commercial monoglycerides (MGs) were added to the COS, and the crystallization behavior, crystal microstructure and physical properties of the COS/MG were investigated. The addition of MGs promoted the crystallization of the COS significantly, modified the crystal subcell structure of COS and contributed to the development of the co-crystalliaztion of MG and the high melting point TGs of COS. A new crystal cluster (sphere-shaped and compact crystal clusters) was observed in COS/MG blends, which might have a relation with the co-crystallization of MG and high melting triglycerides (TGs) of COS. With the increase of MG level in the COSs, the crystalline network become denser. Further, the SFC and the rheological properties (including the viscoelasticity, the resistance to heat and shear force) of COS/MG blends improved by adding MG. The possible crystallization mechanisms were proposed to understand the effects of MG on the crystallization microstructure and rheological properties of COS.