Refining olive oil The Refined Olive Oil Process source: www ...

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The Refined Olive Oil Process source: www.whyoliveoil.com/refining. By definition, refined olive oil is the oil obtain r
Refining olive oil

The Refined Olive Oil Process source: www.whyoliveoil.com/refining By definition, refined olive oil is the oil obtained from virgin olive oils by refining, acidity after refining being 0.3%. The virgin olive oils intended for refining are ordinary olive oil and lampante olive oil. Refining is a process in which the undes undesirable irable compounds are removed, such as: free fatty acids, pigments, gums, unpleasant flavor and odor. Generally, the refining of edible oils and fats is made in two ways: physically and chemically (mostly used). Physical refining is a simple process in one step using steam stripping at a temperature up to 270 degrees Celsius. Has lower cost and less chemicals are used but the final product is of lower quality. Chemical refining has four stages: • Degumming (removal of phospholipids; water and centrifugal sep separation aration are used); • Neutralization (removal of the free fatty acids using caustic soda or sodium carbonate at 95 degrees Celsius); • Bleaching (removal of colour and other constituents); • Deodorization (at 180-270 270 degrees Celsius). In the olive oil processing the same stages are followed with the specification that degumming is replaced with settling because of small amount of phosphatides. Settling is necessary to avoid cloudiness and sentiment in the bottle of olive oil and it also removes moisture, impurities impuriti and some waxes. The crude lampante oil has after this stage 10% acidity, phosphatides, metals, coloring components and water. This will be removed by caustic neutralization when olive oil loses its bad features. Next step, bleaching, will remove the nat natural ural pigments compromised by bad preservation and responsible of unpleasant color, metals and residual soaps. Deodorization is the final treatment, when high temperature is used.

The other half of the story is that refining process removes also the perfect attributes of olive oil. The high temperature, stripping gas, thickness of oil layer in the deodorizer and length of the process create changes to the quality attributes of the olive oil: • remove all natural antioxidants • sterols are mostly removed as well as tocopherols • increases the content of stigmastadienes which show higher PAHs (polycyclic aromatic hydrocarbon) Cold pressed virgin olive oil will have unmeasurable number of stigmastadienes (maximum 0.01 mg/kg), while the refined oil can have up to 30 mg/kg. Stigmastadiene is a hydrocarbon formed as a consequence of thermal treatments during refining process. A recent type of fraud involves destruction of sterols during refining to mask the presence of other vegetable oils in olive oil. The sterols are destroyed and converted to hydrocarbons. Stigmastadiene is what helps to determine the presence of desterolized vegetable oil in virgin olive oil. To conclude, the refining process is not only removing the defects of the lampante olive oil, but it is also destroying the attributes of this product. The refined olive oil is still a highly monounsaturated fat and therefore is preferable to other edible oils but cannot and must not be considered equal to the authentic extra virgin olive oil since it lost taste, color, flavor, its antioxidants and other nutrients. New artificial features were added to create a similar but fake product. The refined olive oil has yellow color and mediocre taste. Actually it tastes bad. The oil might get oxidized easily and have rancid taste. It is not advisable to consume it raw but only for frying. Refined olive oil will be then mixed with virgin oils or will be sold directly as refined. Usually it is labeled as olive oil, pure olive oil or light olive oil. Light indeed, not in calories (since all fats have the same calories) but in all the rest. Terms of marketing refined olive oils in Australia: • Olive oil • Olive oil (composed of refined and virgin olive oils) • Light olive oil • Extra light olive oil • Pure olive oil