Leguminous fractions as encapsulating agents of fat-soluble vitamins

Vitamins are essential micronutrients for the functioning of the human body. Vitamins can be classified as water-soluble and fat-soluble, and are obtained through diet or supplementation. Fat-soluble vitamins include vitamin A, vitamin D, vitamin E, and vitamin K. These compounds are very sensitive to external factors, including light, oxygen, pH, and temperature. Lack of compound stability, poor solubility, and low permeability can compromise the bioavailability and usefulness of fat-soluble vitamins. The methodology of encapsulation of vitamins is currently being widely studied in order to improve their transportation and usage. Proteins (including protein isolates and concentrates) and carbohydrates derived from legumes are very interesting materials to coat compounds, considering their functional properties, and the fact that they are beneficial for the environment and human health. This review describes in detail the current knowledge about the use of legume protein and carbohydrates as materials for the encapsulation of fat-soluble vitamins. The functionality, health, and environmental advantages of legume fractions (particularly soy and pea fractions) as wall materials are also discussed. Future use of legume wastewater (soaking and cooking water derived from the treatment of legumes) as wall materials is evaluated as well. The study of encapsulation of fat-soluble vitamins by leguminous fractions is mainly focused on soy and pea protein isolates and concentrates and can still be expanded, considering the numerous benefits of encapsulation they provide. Research on encapsulation using legume carbohydrates is scarce and may be interesting due to their high encapsulation efficiency and easy digestibility. Saponins, proteins, and carbohydrates present in legume wastewaters could offer useful properties to encapsulation processes, while benefiting the environment.