Abstract:

The storage stability of microalgal oil microcapsules was investigated by determining physico-chemical properties. The moisture content, the encapsulation efficiency, the average particle size and the solubility of freshly prepared microalgal oil microcapsules were 3.68%, 94.30%, 497.9 nm and 94.37%, respectively. All these indexes were relatively stable during 180 d storage. The core material was found to be well protected under scanning electron microscopy (SEM). DSC analysis indicated that the Tm of microalgal oil microcapsules was high, suggesting that the complete structure of microcapsules can exist stably during thermal processing. A slight decrease in the thermal stability was seen during storage. With the temperature increasing, the microcapsule damage rate increased in heat resistant strength test, suggesting that microalgal oil microcapsules should be stored at low temperature.

Key words: micro-algal oil, DHA, microcapsule, physico-chemical properties, stability