Micro-encapsulation of refined olive oil: influence of capsule wall components and the addition of antioxidant additives on the shelf life and chemical alteration

BACKGROUND: Although refined olive oils (ROOs) exhibit lower quality and less stability toward thermal stress than extra-virgin olive oils, these types of oil are gaining importance in the food industry. The inclusion of ROOs in processed food may alter the oxidative stability of the manufactured products, and therefore having technological alternatives to increase oil stability will be an important achievement. For this reason the main goal of this study was to assess the influence of the micro-encapsulation process on the ROO chemical composition and its oxidative stability. Factors such as microcapsule wall constituents and the addition of the antioxidant butyl hydroxytoluene were investigated in order to establish the most appropriate conditions to ensure no alteration of the refined olive oil chemical characteristics. RESULTS: The optimised methodology exhibited high encapsulation yield (>98%), with micro-encapsulation efficiency ranging from 35 to 69% according to the nature of the wall components. The encapsulation process slightly altered the chemical composition of the olive oil and protected the oxidative stability for at least 11 months when protein components were included as wall components. CONCLUSION: It was concluded that the presence of proteins constituents in the microcapsule wall material extended the shelf life of the micro-encapsulated olive oil regardless the use of antioxidant additives. Copyright (C) 2012 Society of Chemical Industry