Alternativas tecnológicas para la incorporación de aceite de chía en alimentos funcionales

MABEL C. TOMAS

Congreso; World Congress on Oils & Fats and 31st Lectureship Series. XVI Congreso Latinoamericano de Grasas y Aceites; 2015

ISF, AOCS, ASAGA

Stability of chia essential oil can be enhanced throught microencapsulation. Microencapsulation by spray drying is widely used in the food industry for the preparation of dry stable functional ingredient. The process involved the emulsification of the core material with a dense solution of wall material such as proteins, gums, carbohydrate and the atomization and drying of the emulsion. An increasing interest is the use of biopolymer blends as wall materials in order to enhance the encapsulation efficiency and to extent the shelf life of microcapsules.The selection of wall materials can influence the emulsion stability during its formation and upon the drying process which could affect the characteristics of the resulting microcapsules.Also, emulsification is one of the important and critical steps in spray-drying microencapsulation of oils as the emulsion stability and doplet size play a key role in the encapsulation efficiency during and after the process and on microcapsule characterization. Lipid oxidation in emulsions is expected to be initiated at the interface between oil and water. The emulsifier used to build the interfacial layer might therefore be crucial for the resulting oxidative stability. The type and concentration of emulsifier determine the structure and thickness of the interfacial layer, and emulsifiers can furthermore have different antioxidative properties. Moreover , the oil droplet size has in some cases been shown to influence lipid oxidation. This was explained by the fact that smaller droplets have a larger contact area between prooxidative transition metal ions in the water phase and lipid hidroperoxides present at the oil-water interface. Oil droplet size is known to be influenced by different factors such as the type and concentration of the emulsifier used, the emulsification equipment and the homogenisation conditions. Milk proteins, caseins, are commonly used as emulsifiers by the food industry because of their good emulsifying and physically stabilising properties. During emulsification they are easily adsorbed at the surface of the oil droplets with more hydrophobic amino acid regions projecting into the water phase, and the less hydrophobic regions facing the oil phase. Thus, the aim of this work was to investigate the influence of homogenisation conditions and emulsifying agent concentration on physicochemical stability of chia O/W emulsions.