Evaluation of Traditional and New Processing Aids for Olive Oil Extraction

Processing aids in olive oil extraction have been introduced to improve paste extractability. Talc powder, enzymes, and warm water have been the most commonly used processing aids. New processing aids and techniques such as common salt, calcium carbonate and hot water dipping have been also evaluated in recent works. This research aims at studying the impact of the use of processing aids on both oil quality and paste extractability when dealing with three of the most important Australian cultivars: 'Arbequina', 'Barnea' and 'Manzanilla'. The processing aids/techniques evaluated were: talcum powder of different particle size, common salt, calcium carbonate, pectinase enzymes with different activity and warm water dipping. Talc powder and calcium carbonate improved paste extractability on all olive cultivars but their impact was more significant in high moisture fruit. Both enzymes and common salt also improved paste extractability in cultivars 'Arbequina' and 'Barnea', but showed no improvements in high fruit moisture 'Manzanilla'. The use of enzymes and common salt did not affect negatively oil quality. The warm water dipping technique provided erratic results and was found to be of difficult implementation at processing plant level. The impact on oil quality was variable depending on the type of processing aid used.