Synthesis and crystallization purification of phytosterol esters for food industry application

Abstract

This work aimed to investigate the process parameters of phytosterol esters (PE) synthesis catalyzed by copper oxide-nano hydroxyapatite (CuO-NHAP) and the crystallization purification technology. CuO-NHAP was prepared. The synthesis of PE catalyzed by CuO-NHAP was performed. After Response Surface Methodology optimization, the optimal process parameters were as follows: reaction temperature, 180 ^oC; reaction time, 6.3 h; acid-alcohol molar ratio, 1.9; catalyst amount, 1.05%. Under these conditions, the esterification rate of phytosterols was 99.8%. The crystallization purification technology of esterification product was explored. The optimal crystallization conditions were as follows: crystallization solvent, octanoic acid; crystallization temperature, 0 ^oC; solvent-product molar ratio, 4: 1; crystallization time, 10 h. Under these conditions, the unreacted fatty acids and other impurities were affectively removed, and the PE purity in purification product was 98.2%. These synthesis and crystallization purification technologies of PE are relatively green, safe, efficient and economic, and have the potential to be applied to the industrial preparation of PE product.

Keywords:
phytosterol esters; synthesis; CuO-NHAP; crystallization; octanoic acid