5.3 THE EDIBLE OIL INDUSTRY OLIVE OIL PROCESSING The process for making olive oil is relatively simple as it relies on a basic principle: crushing the olives to the oil trapped inside. The characteristics of olive oil are determined by: release the variety of olive, climate, 1 growing conditions, harvesting methods, pressing method. DO Which Italian regions are big producers of olive oil? 1 Harvesting is the first important step. Olives should be harvested at the right moment of ripeness, when they are changing colour from green to black, so that the concentration of oil in the fruit is high. The harvesting method also has an important effect both on the quality of olives produced for table consumption and on the quality of olive oil. Traditional methods involve the olives into nets by hand or hand picking into baskets, although today tree shaking machines or picking platforms are also used. Fruit mechanically harvested has 35% more and three times as many with broken skin as that of hand-harvested fruit. When the fruit is picked carefully by hand, no injuries to olives may be inflicted. Consequently, free fatty acids levels and peroxide are substantially reduced, and total polyphenol content is increased. Harvesting combing bruising 1 MORE There are three techniques of hand harvesting: collection of fallen fruit from the ground; stripping of fruit with half-open hands from limbs, making the olives fall into picking bags or onto nets below the tree; beating with large sticks to dislodge fruit, which is collected in nets. 1 limbs Processing Once the olives have been picked, they must be taken to an as soon as possible (within 48 hours), since their vegetable water content may ferment and their acidity level may climb too high, affecting flavour. The production steps are: olive mill After being brought to the mill, the olives are inspected to remove large branches and leaves, and then washed; Cleaning and washing. The cleaned olives are a which turns them into a paste. Traditionally-made olive oil is still produced using a to mill olives, whereas commercial processors use high-volume metal grinders which can operate continuously; Grinding. run through milling machine stone grinder Slow mixing for 20 to 40 minutes allows small oil to combine into bigger ones: the correct procedure will ensure the ultimate uniformity of the oil; Malaxation. droplets After mixing, the olive paste is put under pressure to extract the liquid oil along with water from the fruit, leaving the paste or behind; Pressing. pomace The olive oil is separated from water, usually with a centrifugal machine or by means of natural Finally, the olive oil is poured into a steel container where it will be stocked in a dark, cool place before bottling. Separation and bottling. decanting.