The Preparation Of Instant Pullulan Particles

Pullulan has been widely used in the fields of pharmaceutical manufacturingthe, food packaging, fruit preservation in the world, because of its unique physical, chemical and biological properties and excellent film-forming, fibrous-forming, gas barrier, adhesion, besides easily to process, be degradation. But liquid pullulan fermented is intolerance storage at room temperature, the way of frozen cannot completely solve the storage problems of liquid pullulan. Powders was prepared with pullulan solution fermentated commonly by evaporative crystallization and ethanol precipitation, but the solubility of the powder prepared by the two methods is not very satisfactory and substantially insoluble at room temperature within a short time. If pullulan is applied widely, the storage of liquid pullulan must be solved firstly. The preparation of instant the pullulan sugar particles can solve the problem of liquid pullulan intolerance storage at room temperature to a certain extent.Spray-Freeze Drying (SFD) is a new technology that feed solution is atomized firstly, contacted with cold media, such as liquid nitrogen, cold gas etc, and then dried into powder. SFD technology is also a fast and controllable process which produces particles and powers directly, and overcomes some shortcomings of the cake products in freeze drying well-known. Powders prepared by SFD technology have the advantage of good flow property, a large surface area, porosity, solubility, stability, etc.This paper produced the particle of pullulan to improve its solubility by spray freeze drying. The author researched the influence of concentration of pullulan solution, freezing temperature of single particle on solubility of dried products, and the property of the particles were qualitative evaluated from the microstructure and the specific surface area. The concentrations were 5%,10%,15%,20%, the freezing temperatures were-15?(SFG) and-196?(SFL).The result showed that most of pullulan particles dissolved completely in 30-50s at room temperature, which were prepared by spray freeze drying, compared the powder prepared by evaporative crystallization were insoluble in 60s, thus the solubility of particle produced by spray freeze drying had greatly improved. Compared to the particles prepared by SFQ the solubility of particles prepared by SFL was preferable.