Oilseed treatment by ultrasounds and microwaves to improve oil yield and quality: An overview

Efficiency is a key point to ensure the profitability in the production of vegetable oils from oilseeds. To maximize the recovery yields of seed oils, the traditional process involves mechanical expression followed by subsequent chemical extraction using organic solvents (e.g. hexane). Besides health, environmental, and economic related issues to the use of organic solvents, thermal treatment of seeds during conventional oil extraction process inevitably leads to chemical changes (e.g. changes in macronutrients such as protein denaturation/degradation in the meal, oil oxidation, and changes in minor constituents such as fatty acids, sterols, phenolic compounds and tocols). Thus, at this stage of development there is a need for new efficient processes that can improve oil yield and its quality from an economical and environmental point of view. Several research groups have investigated the potential of ultrasounds (US) and microwaves (MW) as additional seed treatments to enhance oil yields and to reduce temperature and extraction times with promising results. The present review is devoted to critically discuss the main findings reported in the literature regarding the feasibility of using US and MW as potential tools to improve oil recovery yields as well as its nutritional, sensorial and physicochemical properties. (C) 2016 Elsevier Ltd. All rights reserved.