Microencapsulation of algal biomass (Tetraselmis chuii) by spray-drying using different encapsulation materials for better preservation of beta-carotene and antioxidant compounds

The awareness of harmful effects of synthetic compounds and an inclination towards the usage of natural products have led to the exploitation of microalgae as a source of natural colors. Because of their health benefits, algal pigments have massive commercial value as natural colorants in the nutraceutical, cosmetics, and phar-maceutical industries. One of the important natural sources of microalgae are antioxidants, bioactive components: such as polyunsaturated fatty acids, beta-carotene, sulfated polysaccharides and sterols. However, these antioxidant-rich fractions and carotenoids possess low storage stability and exhibit high sensitivity to light, heat, and oxygen. During the extraction process, there is some loss of required materials, and also, chances of the contamination from toxic solvents. There are few reports on algal-extract encapsulation and algal biomass encapsulation, and only a few types of wall materials that can show better stability, shelf life, and controlled release have been investigated. In this work, we investigated micro-encapsulation of the fresh algal biomass of Tetraselmis chuii and studied the effect of the wall material and the processing conditions of the spray dryer on the preservation of beta-carotene and antioxidant compounds. Our studies revealed that a native species of Tetraselmis from Mexico, which is an important aquaculture feed, produce a considerable amount of beta-carotene as much as 1.3% of its biomass. We found preservation of 80-92% of beta-carotene and 46-81% phenolic-compounds in freshly microencapsulated microalgae even after three months of storage in dark condition at 25 degrees C, maltodextrin at 130 degrees C was found the best wall material. This alga is suitable for use in aquaculture and food industry because fresh microalgae can be microencapsulated without loss of its nutritional values, and it is easier to handle and transport This can serve as a functional food with better preservation of its antioxidant value and can be processed without any toxic solvent component.