Microencapsulation of vitamin A: A review

•Vitamin A deficiency is recognized as a public health problem.•Vitamin A has poor solubility in water and chemical instability.•Microencapsulation may promote the stabilization of vitamin A.•Vitamin A can improve a healthy nutrition.•Microencapsulation of vitamin A is important for food application.

BackgroundVitamin A deficiency is recognized as a public health problem in a large number of countries. It mainly affects young children and pregnant women in low-income countries in Africa and South-East Asia regions (World Health Organization data).Vitamin A is a fat-soluble vitamin and an essential nutrient provided to the human body in form of carotenoids (provitamin A) and retinol or retinyl esters (preformed vitamin A). The inadequate intake of this micronutrient through the diet may compromise a large spectrum of biological functions, namely vision, growth and development, immunological activity, reproduction and cellular growth and differentiation. The preparation of functional food and enteral formulas arises as a solution to provide to the individuals the partial or complete vitamin A nutritional requirements.Scope and approachDue to the properties of vitamin A and other retinoids these compounds have been used for several pharmaceutical and cosmetic formulations. However, the poor solubility in water and chemical instability of vitamin A can lead to its degradation during processing and storage. Microencapsulation may promote the stabilization of vitamin A in certain conditions and may improve a controlled release.Key findings and conclusionsThe present work starts with a reference to several topics of vitamins A. General aspects about microencapsulation are presented, as well as the reasons to apply this technology to vitamin A. The main encapsulating methods (the principles and main considerations) and encapsulating agents applied to this micronutrient are also discussed. The final section focuses on vitamin A release studies and its kinetics.