domenica 11 novembre 2012

Clichés, prejudices, and truth on Extra Virgin Olive Oil E.V.O.

Here is a more or less complete list of the various Clichés, prejudices, and truth on Extra Virgin Olive (E.V.O.) Oil. Our goal is to try to confirm whether or not it is justified. 


 - that olive oil is more fat oil seeds. In reality, all oils contain the same amount of fat (99%) and provide ± 9 kilocalories per gram and therefore does not more fattening than seed oil, on the contrary, being more flavorful and viscous greater satisfaction to the taste and bastandone a smaller amount also allows us to save money.
 that the oil dietary or oil light does not make you fat. The oil is an oil diet supplemented with vitamins and other essential components (many already and fundamental characteristic of olive oils). The oil light has a color not too bright, which apparently gives a feeling of low density. The calorie-energy is the same for all oils (including seed) and the assumption that a coloration "charge" would correspond oil "heavier" and therefore less digestible, is absolutely false.
 - the best system of extraction is the traditional one for pressure. In fact, modern systems of extraction centrifugation or percolation, if well managed, can produce oils better quality than conventional systems because not permit exchanges with moliture earlier
- that the cold-pressed oil is a special type. Good standards of machining require, during all stages of the production process, the maintenance of the lowest possible temperatures (the processing temperature of the olive paste with a conventional system is about 18-22 ° C, while molendoleabsolutely cold is impossible, since the simple mechanical process of crushing creates heat; the addition of very hot water can alter the components of the baggage organoleptic (smells and tastes) of the product. However, if we press the "cold" olives poor, we will have an extra-virgin olive oil obtained by "cold pressing" but definitely of poor quality.
- virgin oil from the first pressing is particularly valuable. Indeed the term "first cold press" means only that it is an oil "virgin", but it is always possible that the result of the first pressing is an oil with missing titles to fit in category of extra virgin
- for a liter of olive oil are It takes about 5 kg of olives. On average, the oil obtained from olives is 20 % by weight, with variations depending on the cultivar, from the time of collection, production of office, by the seasonal, the extraction system, etc. ..
- the color of the oil determines its quality. The professional tasters use a colored glass in order not to be influenced. Green with yellow more or less intense, depends only on the cultivar, ripeness and the process of extraction. The oil color is an indication of impairment only in the presence of reddish reflections (the oil has deteriorated because it was stored unprotected from light).
- that Italian extra virgin is the best in the world.  True and False. In some areas (Umbria, Tuscany, Apulia, etc.), thanks to the particular cultivar, environment , cultivation techniques and extraction, you can get the oils that are the "top". Be careful because in the same areas, disregarding the rules of production quality, you get bad oils. In different parts of the world you can get a quality oil.
- that quality depends only on the extraction system. Many factors determine the quality of an oil. The most important are: the environment, the cultivar, the farming techniques, the time and the system of collection, the duration and conditions of storage of the olives, the technology of processing and storage conditions of the oil. A high quality oil is obtained by choosing appropriately the cultivation environment and cultivars, avoiding parasites, picking olives in optimum period (November), making harvesting olives from the tree and not on the ground, put the olives in aerated plastic containers and not in bags and store them in a cool, ventilated, milling within 24-48 hours and adequately managing the extraction systems, paying particular attention to hygiene, limited contact with oxygen and temperature control.
- that after a few months the oil loses its qualitative characteristics. No .. oil should be preferably consumed within 12-15 months, because after that period it loses its main organoleptic qualities (color, taste, aroma, etc.), however, especially if the oil comes from cultivar characterized by high content of polyphenols, if the collection was made in the best period, and if the storage was adequate, the oil can maintain high quality characteristics for a year and a half.
- the best containers for oil are those in terracotta. The best containers are stainless steel ones. Are also excellent glass containers opaque (i.e. non-transparent to light). It is preferable that the shape of the containers having the bottom and the mouth of the narrower central part, so as to reduce the contact surface respectively with the sludge and with the air. Are to avoid the plastic containers because they easily spread their scent oil.
- that olive oil should not be good for frying. Indeed is one of the best fries though certainly more expensive. In fact, withstand very high temperatures without burning (smoke point) and therefore without producing toxic compounds. The advertising insists on seed oils that would ensure fries "read", but it did not with reality.
- that the turbidity of an oil is a sign of poor quality. The of good quality olive oil (extra virgin and virgin), turbidity, if the oil has not been subjected to filtration driven, is a natural phenomenon that tends to decrease with time. At the bottom of the container, it forms a deposit of sludge which you should delete with a transfer.
 - that  an oil that "pinches in my throat" has high acidity. The acidity of the oil is not perceptible to the taste, but can be determined only with a special analysis in the laboratory. The feeling of "tingling" (spicy) is, instead, a positive feature oil, characteristic products in young, because of the presence of substances healthy antioxidants (polyphenols and tocopherols), and its intensity depends essentially on the cultivar, by 'ripening period, from the extraction system and the manner and duration of conservation of the oil. Medicine attaches to these substances a key role against cell aging. 


- that olive oil is good for health. It protects the heart and arteries, it slows down brain aging, prevents atherosclerosis, lowers the level of cholesterol " bad "(LDL) and increases the" good "cholesterol (HDL or" scavenger of the arteries "), protected by monounsaturated fatty acids that is rich in olive oil, prevents the occurrence of tumors and cell deterioration. Olive oil, for its fatty acid composition is similar to breast milk, it is always recommended weaning children and is useful in old age because it promotes the absorption of calcium and mineralization, preventing osteoporosis. The recognition of the best nutritional properties of olive oil over animal fat then generated the misconception that all fat of vegetable origin are good and do well. The result is that some substitute margarine for butter (actually it less caloric oil because it contains water, but has other disadvantages) believing that protect their health. The margarine is produced by hydrogenating vegetable oils, ie making it saturated the double bonds of fatty acids through the absorption of hydrogen. In this way the benefit that vegetable oils lead to the prevention of cardiovascular diseases, especially linked to the presence of mono-and polyunsaturated fatty acids, is totally cleared. Another very common mistake is to believe that the best way of life to follow to prevent increase in cholesterol and in general good health and the adoption of a diet as can be poor fat: a diet low in fat tends to lower cholesterol is good and the bad, with an obvious impairment of bodily function.
- that not all the oil classified as" olive oil "is of high quality.  Because often is obtained by blending of rectified olive oil and virgin olive oil other than lampante, whose acidity, expressed as oleic acid may not exceed 1.5. Olive oil with excellent features, however, is the olive oil. 
- that oils D.O.P. (Protected Designation of Origin) offer high quality assurance. The DOP is awarded by the European Community to those oils produced in certain areas that meet a particular set of very rigid, thus ensuring that both characters typical of very high quality standards. can bear the DOP oils produced on all the territories of the countries of the European Community. The recognition D.O.C. (DOC), however, recognizes only valid in the country.
- that the time of harvest influence strongly the quality of the oil. From olives harvested in early maturation (end of October, beginning of November), you get an oil with organoleptic more fruity, more bitter and spicy. From olives harvested when ripe submitted, however, you will get an oil less fruity and less bitter. In addition, the oil obtained from olives harvested in early maturation will be richer in antioxidants (polyphenols) that increase stability and preservation.
That the acidity is an indicator of quality. The acidity is a parameter that indicates the percentage of oleic acid in an oil and is the main indicator of the quality. The higher its value, the poorer is the quality of the product. The acidity is a direct consequence of the release of fatty acids due to hydrolysis of the glycerides, and is a quality parameter defined only by laboratory testing. It is the parameter that allows you to assess any changes in the olives and the oil obtained from them suffer during collection, transport and transformation process. Moreover, its evaluation allows the commodity classification of the oils. The determination of acidity is carried out in the laboratory and a simple analysis is that, by now, almost all the mills can run autonomously. For the precise definition of the concept of free acidity is important to note that the extra virgin olive oils are composed of triglycerides by 98-99 % ie esters formed from glycerol and fatty acids. A part of the latter, however, remains in the free state not combining with the glycerin by determining, in fact, the acidity of the product. These free fatty acids in the oil may increase if acting on a specific enzyme called lipase that is found in the fruit and the process can take action , especially if the drupe suffered injuries phones ( insect attack , injury during collection and transport , poor agricultural environmental ) . The enzymatic activity of the lipase is also favored by rather high temperatures, between 30 ° C and 40 ° C. Therefore, it can be concluded that the degree of acidity of an oil is strongly influenced by the health of the olives, the technology of the collection, storage time, the processing technology used (Elevated temperatures kneading) and care placed by operators in the processing and storage of the product. It is classified as Extra Virgin olive oil with a free acidity content of less than 0.8 g / liter.
- That one kilogram of oil is more than one liter of oil. The specific gravity of the oil at 15 ° C is of 0.915 to 0.919 (kg/m3), therefore a liter of oil has a weight of 915-919 g.

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