Optimization of the preparation process of algae oil microcapsules and analysis of influencing factors of its shelf life

Docosahexaenoic acid (DHA) obtained from algal oil has been reported to have several benefits to human health. However, one of the major challenges in utilizing algal oil DHA is its oxidative deterioration, which can be solved by microencapsulation. Microencapsulation refers to the process of spray-drying that improves the quality of microcapsules. In the present study, we used the single-factor analysis to study the effects of inlet temperature, outlet temperature, and fan frequency on microcapsule properties, and further identified by orthogonal experiments. The optimized process conditions were an inlet temperature of 180 °C, an outlet temperature of 80 °C, and a fan frequency of 65. Under these conditions, the quality of microcapsules, shown by physicochemical properties, was greatly improved. The quality guarantee period of microcapsules was more affected by storage temperature and slightly affected by oxygen and light. The storage experiments demonstrated that the shelf life of laboratory-prepared DHA microcapsules at room temperature was beyond 13.5 months. We believe that this study will provide significant insights into the development of high-quality DHA microcapsules.