Improving the stability and bioactivity of curcumin using chitosan-coated liposomes through a combination mode of high-pressure processing

This study used chitosan-coated liposomes of curcumin (cur-chitosomes) coupled with a combination mode of high-pressure processing (HPP) and ethanol injection to improve the bioactivity, preservation, and thermal stability of curcumin. The results revealed cur-chitosomes presented the best thermal stability and encapsulation efficiency. With 0.1% chitosan addition, the encapsulation efficiency increased from 73.8 to 84.0%, accompanying with less increases on particle size and polydispersity index. Storage stability for 28 days incubation demonstrated the particle size of cur-chitosomes remained at a constant value, which presented the long thermal stability due to the static electrostatic repulsive force. The stability of cur-chitosomes presented high value of 85.3% at degradation conditions of 25 °C and 480 min. With thermal kinetic calculation, the half-life of curcumin-loaded liposomes and cur-chitosomes were 625 and 1250 min at 25 °C, so liposome formation and chitosan addition in curcumin could increase the storage time. Over 104 CFU/g Escherichia coli, Staphylococcus aureus, and Staphylococcus aureus could be completely sterilized in the preparation of cur-chitosomes at 400 MPa HPP. Consequently, chitosomes by HPP not only prevented the thermal degradation of heat-sensitive substances but also enhanced the storage stability and the sterilization effect in a non-thermal process.