Abstract:Antarctic krill (Euphausia superba) is a species of krill found in the Southern Ocean, and an important strategic resource of China, whose growth and reproduction are susceptible to the Antarctic water environment. Due to their huge biomass (estimated to be 125 to 725 million tons), nutrient contents, and active ingredients, Antarctic krill can be widely used in functional food, aquaculture, medicine, and other fields. As an important extractive, astaxanthin has high antioxidant activity and could play an important role in anti-oxidation, anti-inflammatory, anti-tumor, and immunity enhancement treatments, as well as in the prevention of cardiovascular diseases. However, astaxanthin has poor stability and poor water solubility, as the molecules are easily damaged by oxygen, light, and heat. In order to reduce the oxidation rate of astaxanthin and improve the storage stability of astaxanthin, the use of maltodextrin and hydroxypropyl-β-cyclodextrin (HP-β-CD) as the wall material for the microencapsulation of the Antarctic krill astaxanthin by spray drying and the physical and chemical properties of the product after microencapsulation were studied. The results showed that when the mass ratio of maltodextrin to HP-β-CD wall material was 1:3, the mass fraction of astaxanthin was 4.76%, the mass fraction of polysorbate-80 was 0.87%, and the solids concentration was 0.20 g/ml; the microencapsulation efficiency of astaxanthin microcapsules was 98.77%. The water content of the prepared astaxanthin microcapsule was (3.11±0.11)%, the solubility was (94.32±0.08)%, and the angle of rest was (34.16±0.24)°. Stability experiments showed that compared to the non-microencapsulated astaxanthin crystals, astaxanthin microcapsules at high temperatures, the retention rate of astaxanthin increased from 28.72% to 78.32%; under natural light conditions. The astaxanthin retention rate increased from 45.27% to 84.88%; under aerobic conditions and the retention rate of prime increased from 20.76% to 74.97%. The above-mentioned results indicated that microencapsulation can significantly improve the solubility and stability of astaxanthin, which can provide technical support for the preparation of astaxanthin microencapsulated products.
