Crystallization behavior and nano-micro structure of lauric acid-rich fats with and without indigenous diglycerides

Crystallization behavior and nano-micro structure of lauric acid-rich fats were investigated in the absence and presence of corresponding diglycerides (DAGs) with a concentration of 2%. Results showed that the melting point and onset crystallization temperature of fats with DAGs were promoted due to the interaction of DAGs with triglycerides (TAGs). Crystallization kinetics found that the addition of DAGs shortened the fat nucleation time, and slowed down the crystal growth rate. Based on X-ray diffraction results, adding DAGs led to the decrease of the thickness of the crystalline domain and alteration of crystallization pattern. Synchrotron radiation small-angle X-ray scattering measurement further revealed the existence of fat crystal nanoplatelets with a rough surface in all the lauric acid-rich fats. However, larger structures of crystalline nanoplatelets appeared in the fats with 2% DAGs. Furthermore, denser and uniform microstructure networks appeared with more tiny crystals and higher fractal dimensions after the addition of DAGs.