Preparation and properties study of phase change materials for fruits and vegetables preservation

Abstract

In order to solve the problems that there are few kinds of cold storage agents suitable for fruit and vegetable preservation, the latent heat of phase change is less than 300 J/g, and there exists the phenomenon of supercooling, the performance of phase change cold storage agents is studied. Firstly, by using the DSC, the aqueous solution formed by proper phase change temperature regulator is selected to get the main energy storage agents with phase transition temperature of -6～-4 ℃ and a higher phase change latent heat. Secondly, through adding different kinds of nucleating agents, the supercooling phenomenon of the main energy storage agents is suppressed. At last, the performance of the better formula of cool storage agent is studied, and two main energy storage agents consisting of temperature regulator with sodium benzoate as main component and aqueous solution, BL-1 and BL-2, are obtained for the first time. The study shows that by adding nucleating agent diatomite, two low cost cool storage agents with phase-transition temperature of -6～-4 ℃ as well as phase change latent heat above 300 J/g and no supercooling phenomenon can be obtained, which are suitable for temperature controlled packaging o fruits, vegetables and other temperature sensitive products whose cold storage temperature is at 0～4 ℃. The developed phase change cold storage agent meets the requirements of food safety and environmental protection, and provides guarantee for the cold storage requirements of related products.

Keywords

• functional polymer
• fruit and vegetable fresh-keeping
• cool storage agent
• main energy storage agent
• nucleating agent