Purpose: The purpose of this study was to test the feasibility of using a nonthermal method, natural antimicrobial curcumin, for pasteurization of TCW.
Methods: A cold pasteurization method was developed by passing the TCW at 4oC through a glassbeads filter medium, coated with 50mM curcumin encapsulating nano-liposomes, leading to extended release of the natural antimicrobial curcumin into the coconut water. Listeria monocytogenes and Escherichia coli W1485 were used as model organisms to test effectiveness of cold pasteurization. Nano-liposomes were prepared by the film rehydration method to encapsulate curcumin. A glass pipette was filled with the immobilized nano-liposomes on glass-beads to form the filter medium. The antimicrobial effect was tested by passing inoculated TCW with Gram positive L. monocytogenes and Gram negative E. coli W1485 through separate columns. The effect of the residence time of TCW in the column was observed by passing the inoculated TCW through the column multiple times.
Results: Reduction of L. monocytogenes and E. coli W1485, in pasteurized TCW, were observed to be reduced two log and one log, respectively, after five passes. Further experiments are suggested with higher residence time of TCW in filter medium to acheive the desired five log reduction.
Significance: Curcumin nano-liposomes are a potential antimicrobial that may be useful in the development of cold pasteurization technology for TCW. Large scale filter medium may be engineered for mass production of pasteurized TCW.