MECHANICAL EXTRACTION OF PLANT ANTIOXIDANTS BY MEANS OF OILS

A simple mechanical process was developed for extracting natural antioxidants from plant materials with a food-grade oil as carrier, avoiding the use of organic solvents. Oily extracts with a high extraction yield could be obtained by the combined application of heat, water, enzymes and mechanical energy. After an appropriate pretreatment, the plant material was contacted with an oil in a plough-share mixer (Lodige) followed by a pressing on a piston press (Carver) which resulted in a limpid oil immediately. Different plant materials, preferably rosemary or sage or mixtures of several spices, were used. Carriers were chosen among high oleic oils, but qualitatively the best extracts were obtained with MCT oil, owing to the high polarity and the excellent oxidative stability of this carrier.