By: Thomas Affatato
Certified Olive Oil Consultant, Italian Culinary Institute, New York, N.Y.
Classification of Olive Oil
Classification
The bulk of olive oil (98.5%-99.5%) is made up of what is known as the “saponifiable” fraction. This consists of triglycerides-esters of glycerol with fatty acids-and free fatty acids. In olive oil, there is a prevalence of fatty acids with 18 carbon atoms.
They can be joined by single bonds and one double-these are monounsaturated fatty acids-or by several double bonds, in which case they are known as polyunsaturated fatty acids. The behavior and characteristics of olive oil depend to a large extent on the proportions of fatty acids. The behavior and characteristics of olive oil depend to a large extent on the proportions of fatty acids they contain.
Olive oil also contains a preponderance of oleic acid, which is a monunsaturate. Fatty acid proportions vary in olive oil depending on region, olive variety, year, etc., and fall into the following ranges.
· Saturated fatty acids: 8-27%
· Monounsaturated fatty acids: 55-83%
· Polyunsaturated fatty acids: 3.5-22%
The other fraction in olive oil is known as the “unsaponifiable” fraction. It accounts for a very small part, but is of great significance for its biological value. The chlorophyll content, which gives a green color, and the carotene content, which is reddish pigment, lends each oil its final color. The volatile aromatic components influence odor and flavor. Polyphenols account in part for flavor but due to their antioxidant nature, they have a decisive effect on the stability of the oil (in other words, on its keeping properties and its resistance to degenerative phenomena).
Tocopherols are also present-predominantly vitamin E (alpha-tocopherol), which also has antioxidant properties. Sitosterol is the major sterol found. Olive oil contains no cholesterol.
Processing Virgin Olive Oil
Virgin olive oil is oil obtained from the olive solely by mechanical or other physical means under conditions-especially thermal conditions-that do not lead to the deterioration of the oil. It must not have undergone any treatment other than washing, crushing, and preparation of the paste, separation of the solid and liquid phases, decantation and/or centrifugation, and filtration.
Virgin olive oil is therefore the oily juice of a fruit (the olive). It is virtually the only oil that can be consumed as it obtained from the fruit, and when properly processed, it maintains unchanged the flavor, aroma and vitamins of the fruit.
To produce quality oil, whole sound olives must be used. This is why farming practices have a significant bearing on the quantity of olives obtained and why they are important in creating the best conditions for the fruit to bear a good oil. The way the olives are handled at the mill will also affect quality because unless every stage of processing is carried out properly, the potential quality contained in the fruit may be at risk.
Arriving at the Mill
Upon arrival at the mill, the fruits has to be classified in terms of variety so that each class can be processed separately: whether it is sound or has been attacked by pathogens, or whether it has been damaged by olive fruit fly (dacus) or leaf blight (Gloeosporium). The olives must be clean when they enter the mill. Some producers also use sorting and washing equipment in the mill itself.
Quality oils are obtained when the olives are crushed as quickly as possible since the storage triggers fermentation processes in the fruit. When there is a delay in the crushing of the olives, the oil in the fruit can become increasingly acidic and take on undesirable, detrimental flavors and aromas. If crushing capacity cannot cope with the quantity of olives delivered on a particular day, it is advisable to store the potentially worst quality olives (those picked from the ground or attacked by pests or diseases) and to crush the sound olives immediately or almost immediately.
Designations of Olive Oil
The term “olive oil” denotes oil obtained solely from the fruit of the olive tree: excludes all oils obtained by using solvents or re-etherification processes. It also excludes mixtures with other of kinds oils.
Olive-pomace oils may not use this term either. Olive oil may be called by one of any of the following designations provided it complies with the relevant criteria fixed in the standard.
Virgin Olive Oil is the oil obtained from the fruit of the olive tree solely by mechanical or other physical means under conditions (particularly thermal conditions) that do not lead to the deterioration of the oil. The oil must not have been subjected to any treatment other than that of washing, decantation, centrifugation, and filtration. According to the international Olive Oil Council, one of the following designations must be used when virgin olive oil is intended for consumption in its natural state.
· Extra-virgin Olive Oil is virgin olive oil that has an organoleptic rating of 6.5 out of 9 or more (a score of 9 means that the oil has no defects whatsoever; organoleptic rating, as defined by the International Olive Oil Council and a free acidity, expressed as oleic acid, of not more than 1 gram per 100 grams;
· Fine Virgin Olive Oil is a virgin olive oil that has an organoleptic rating of 5.5 or more and a free acidity, expressed as oleic acid, of not more than 1.5 grams per 100 grams;
· Semi-Fine or Ordinary Virgin Olive Oil is a virgin olive oil that has an organoleptic rating of 3.5 or more and a free acidity, expressed as oleic acid, of not more than 3.3 grams per 100 grams.
Designations of Olive-Pomace Oil
Olive-Pomace is the oil obtained by treating olive pomace with solvents, to the exclusion of oils obtained by re-etherification processes and of any mixture with oils of other kinds, it can be classified as follows:
· Crude Olive-Pomace Oil is olive-pomace oil that is intended for refining with a view to its use in food for human consumption, or that is intended for technical purposes;
· Refined Olive-Pomace Oil is obtained from crude olive-pomace oil by refining methods that do not lead to alterations in the initial glyceridic structure. It is intended for consumption either as in or in blends with virgin olive oil;
· Olive-Pomace Oil is a blend of refined olive-pomace oil and virgin olive oil fit for consumption as is. In no case whatsoever may it be called “olive oil.”   Infinite Health Resources does not at any point, for any circumstances suggest that you do not follow or stop medical advice of your physician. We do not advocate any drugs that has not been prescribed by your physician, nor suggest that we are medical doctors nor are we giving medical advice. Infinite Health Resources is here purely as a resource. |
