Fish Oil Encapsulation Using Soy Proteins as Wall Material: Protocols to Ensure PUFA Protection

Abstract

Currently the incorporation of fish oil in diet is highly recommended due its high content of poly-unsaturated fatty acids, and their proved benefits on health. However, their incorporation into functional food is a significant challenge due to their low solubility in aqueous solvents, undesirable aroma, and high susceptibility to oxidative deterioration. Oxidative reactions could produce free radicals and hydroxides that can be toxic, and volatile compounds such as aldehydes and ketones that negatively affect the sensory properties of food. Encapsulation technique could be used to protect fish oils from lipid oxidation and soy proteins appeared to be suitable as wall material due to their acceptable water solubility, good adsorption at the water/oil interface, and their advantageous gelling and film-forming properties. The objective of this chapter is to describe and discuss the protocols used to encapsulate fish oil in soy protein microparticles by emulsification and spray drying, focusing the process on the oxidative protection of oil, determining the encapsulation efficiency and the oxidative stability of the fish oil through the peroxide value, thiobarbituric acid reactive substances, and the Rancimat test.