EFFECT OF DIFFERENT MALAXATION TIMES AND TEMPERATURES ON THE EFFICIENCY OF EXTRACTION AND QUALITY OF OLIVE OIL

This research was involved in studying the effect of different malaxation time SO, 60 and 70 min. and malaxation temperatures 25, 30 and 35 °C of pastes in a mixer on the quality and quantity of olive oil at industrial scale using a three-phase continuous extraction system. This was in order to reach a minimum oil loss in the pomace and a high content of polyphenols and tocopherols in oil. Also, to obtain the highest, percent of oil from different malaxed olive pastes. The results obtained showed that using malaxation time of 60 min gave the highest oil percent from olive paste and the least residual quantity in pomace, while malaxation time of 50 min gave better characteristics than all samples taken from different stages of processing line, followed by malaxation for 60 min. Results showed that oil percent is higher when malaxed at 35 °C, than malaxed samples at 25 °C and 30 °C. Free fatty add, peroxide value and ultraviolet absorption recorded a slight increase for all samples by increasing temperature. Malaxed sample at 25 ^°C caused a higher increase in natural antioxidant and stability compared with that malaxed at 30^°C and 35^°C. The best quality of oil is obtained from horizontal centrifugal decanter compared with that from vertical separators (1) and (2) (oily and water phases).