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38
УДК 665.327.3
Бенедетто Наталини (проф.)
ОЛИВКОВОЕ МАСЛО И ЗДОРОВЬЕ ЧЕЛОВЕКА: КУРС НА СРЕДИЗЕМНОМОРСКУЮ ДИЕТУ
Университет Перуджи, кафедра Фармацевтических наук, Via del liceo, 1; 06123 Перуджа, Италия, эл. почта: [email protected]
Benedetto Natalini (Prof.)
OLIVE OIL AND HUMAN HEALTH: FOCUS ON THE MEDITERRANEAN DIET
University of Perugia, Dep. of Pharmaceutical Sciences, Via del liceo, 1; 06123 Perugia, Italy, e-mail: [email protected]
Оливковое масло включает до 2% ненасыщенных олеиновых кислот, что определяет его эффективность в качестве натурального антиокси-данта. Более того, оливковое масло состоит почти полностью из триглицеридов жирных кислот (98—99 %) — веществ, образованных химическим сочетанием глицерина с различными жирными кислотами, наиболее распространенными из которых являются олеиновая (65—80 %), линолевая (5—20 %), пальмитиновая (10— 20%). Также эти компоненты оказывают положительное влияние на метаболические процессы в организме человека. Средиземноморская диета, основанная на оливковом масле и широком ассортименте морепродуктов, является наиболее эффективной диетой для развития человеческого организма.
Olive oil includes unsaturated oleic acids till 2% that determines it effectiveness as a natural antioxidant. In addition to it olive oil is composed almost entirely of triglycerides of fatty acids (98— 99 %), substances formed by the chemical combination of glycerol with various fatty acids: those most represented are oleic acid (65—80 %), linoleic acid (5-20 %), palmitic acid (10-20 %). Moreover these components influence positively to metabolic process in human body. Mediterranean diet based on olive oil and a wide range of seafood is the most effective diet for human body development.
Key words: human health; Mediterranean diet; natural antioxidants; nutrition; olive oil.
Ключевые слова: здоровье человека; натуральные антиоксиданты; питание; оливковое масло; средиземноморская диета.
Lifestyle and nutrition have changed considerably over the years Today, the mistake of excessive intake of calories, you want to increase the availability of food, you want to lower physical activity, is widespread in industrialized countries. Very often, this energy super diet is unbalanced in nutrient quantities.
The intake of fat, particularly saturated and poly-unsaturated, increases; the consumption of carbohydrates decreases, with the exception of oligosaccharides (sucrose, lactose, and others) for which increases; also, it increases the consumption of foods of animal origin, with a high intake of high biological value proteins 2. Meanwhile, the intake of saturated fat increases, fresh vegetables are canned and preserved with treatments not always suited to preserve their organic content, and also, the food processing Дата поступления 29.12.16
processes will reduce its content of vitamins, minerals, antioxidants and fibers. All these changes, largely related to the technological progress, to a more and more widespread use of so-called «fast food», or to changes in taste and habits, can only adversely affect the population's health status and increase the incidence of degenerative metabolic diseases. As a consequence, it is necessary to change these eating habits and bring the population to a more moderate and balanced diet, as in the case of the Mediterranean Diet 3. In its broadest sense, the Mediterranean Diet is not only the intake of certain foods, but also includes a way of life peculiar to the inhabitants of the Mediterranean basin. For these people, eating is not the rapid ingestion of healthy products obtained from their 'habitats', but rather the pleasure of eating at the table sharing food with
others, spending some time to enjoy the food and resting after a meal to aid digestion. These factors are essential to the life style commonly called Mediterranean Diet. And among the dietary fats, olive oil plays a leading role.
The term 'olive oil' is commonly used in a generic way to define all oils derived from the processing of olives; in fact, this term encompasses a range of different products for quality and characteristics.
The descriptions and definitions of the various olive oils were sometimes unsatisfactory and capable of creating confusion for consumers and sector operators. The progress achieved by producers and millers have recently increased the number of olive oils of higher classes: to take into account of this trend, changes have been made to the traditional classification fundamentally based on the distinction between extra virgin olive oil (acidity <1%), virgin olive oil (acidity <2%), olive oil (virgin and refined oils mix with acidity <1.5%) and olive-pomace oil (mix. of pomace oil refined with virgin oils, acidity <1.5%).
The table below is an excerpt of the main elements of the product classification of the oils extracted from olives, according to the EEC Regulation n. 1513/2001, in force since nov.lst, 2003.
Table
Main elements of the product classification of the oils extracted from olives
Category Commercial Destination Acidity (%) *
Extravirgin olive oil Direct use < 0.8
Virgin olive oil Direct use < 2.0
Olive oil In bulk > 2.0
Refined olive oil In bulk < 0.3
mix. of refined and virgin olive oils Direct use < 1.0
Crude olive-pomace oil In bulk > 0.5
Refined olive-pomace oil In bulk < 0.3
Olive-pomace oil Direct use < 1.0
* expressed as grams of oleic acid/100 g of oil (Official Journal of the European Communities No. L201/4, july 26th, 2001)
Olive oil is composed almost entirely of triglycerides of fatty acids (98—99 %), substances formed by the chemical combination of glycerol with various fatty acids: those most represented are oleic acid (65—80 %), linoleic acid (5-20 %), palmitic acid (10-20 %).
The health benefits of olive oil were often attributed to a strong presence of oleic acid, mono-unsaturated fatty acid (one double bond in the carbon chain), certainly characterized by a
lower comparative oxidizability and by the ability to lower cholesterol levels, where, however, the above properties arise essentially from the particular composition of the final product.
Among the minor constituents, but no less important, in addition to beta-carotene (provitamin A) and tocopherols (including primarily vitamin E), olive oil contains a number of antioxidants (phenolic compounds) extremely important for the conservation of the oil itself, and from a nutritional and anti-aging point of view, to prevent the formation and damage from free radicals, and phytosterols, useful compounds for their regulating action on cholesterol absorption 4.
Many free radicals are particularly reactive oxygen-containing substances, universally recognized today as mediators of various degenerative and inflammatory diseases such as rheumatoid arthritis, diabetes, cataract formation, immune and brain malfunctions, aging. While a physiological proportion of free radicals is necessary to ensure, inter alia, the proper functioning of the immune system, an excessive production can lead to the above described pathological conditions. Human body has evolutionarily developed protective antioxidant systems of defense and repair systems that prevent the accumulation of molecules damaged by oxidation. The antioxi-dants contained in the extra virgin olive oil were then given special attention for their potential protective effects against oxidative damage from biological oxidants. In particular, beta-carotene and alpha-tocopherol, but also hydroxytyrosol, oleuropein and oleocanthal, have been subjected to extensive studies to clarify the mechanism of antioxidant action and their disease marker potential ability 5'6. Recent studies have confirmed that oleuropein and hydroxytyrosol are powerful 'scavengers' of free radicals, also capable of modulating enzymatic processes relevant for cardiovascular diseases: hydroxyty-rosol for example, showed a platelet aggregation inhibitory activity, thus suggesting a potential antithrombotic action 7.
What steps can be taken to arrive at a final product that meets nutritional, organoleptic and healthy optimal requirements? It is on this ground that we risk a clash with tradition.
For a long time, and probably in every place of cultivation, oil has been extracted from fully ripe olives, often collected from the ground, and then piled in a warehouse awaiting milling. Often the deposit was placed in an upper
compartment to the plane where the grinding was done, thus facilitating the transfer to the grindstone, but favoring also the heating of the olives themselves, also because of the thick layer of the crop resulting from the significant difference between quantity collected and milled product.
The oil thus obtained has particular characteristics: beyond the subjectivity of taste, the product of the pressing of these olives has already undergone an incipient, more or less considerable alteration process that depends on the ripeness and from the wait before milling, and also has a very high degree of acidity. All this, if on the one hand can be justified in a taste perception consolidated over the time, however, is much less compatible with a healthy and safe food, based on the consumption of an oil in which are present preventive and protective substances such as those cited above.
As a consequence, in many places where the olive tree characterizes the local economy, the cultivation-collection-processing-oil production system has changed since long time. Without going into details of the various steps, let's point out some crucial aspects in the overall cycle of oil production.
The best time of olive harvesting is the one where you get the maximum oil production with the best organoleptic characteristics (aroma, taste, flavor, odor, color, etc.). Contrary to popular belief, this stage does not correspond to the most advanced stages of maturation of the olives: in fact, with the ripening progress, the increase of the oil yield of the olives is only apparent, that is, due to a progressive loss of water from part of the pulp and not linked to a further accumulation of oil. The harvest should be performed at the time in which, after reaching the maximum development of the olives and a good oil formation stage, loss of product by falling is still very limited (5%). An oil with high organoleptic characteristics, able to 'typify' the production, is obtained by gathering olives turning only superficially violet between 50-100 %.
The best oil quality, you get, no doubt, by subjecting to milling the olives on the same day of collection. In fact, fruits, once detached from the plant, increase breathing, decrease weight and undergo alterations leading to the reduction and disappearance of substances responsible for aroma and perfume, to the onset of degradation processes which increase acidity and oxidation, and introduce defects in the oil. These changes are accentuated as a result of trauma, bruises and pressure caused by particularly vigorous
collection, by pests and activities of aerobic microorganisms that develop on the whole or traumatized fruit.
But it is not always possible for the mill to work the olive batches that are delivered on a daily basis and therefore it is necessary to store for a few days (max. 3) olives waiting milling. The best storage conditions comprise a rather low temperature (10-15 0C), a low relative humidity (<50-60 %) and the realization of thin layers with air circulation between the various layers (eg. stackable racks, perforated plastic boxes).
However, the smaller is the storage time of the olives, whilst correctly, the better will prove to be the quality of the oil. The subsequent processing steps, pressing or milling, kneading and squeezing, are also important, but probably less critical of the preceding steps being realized with machines.
After pressing, kneading is certainly an important step to promote the breaking of water-oil emulsions formed during the tearing of the pulp and of the core, with formation of increasingly larger oil droplets, separated from the vegetation water. Finally the extraction leading to the final oil production, today realized through two methods based on discontinuous or continuous operation 8.
The first method deals with the more traditional system, the mechanical pressure for extraction: the dough is placed on vegetable or synthetic fiber discs, successively stacked under the press, where the pressure increases over a period of about one hour and producing the leakage of the oily liquid component then directed to the centrifuge that separates oil from all remaining liquid. The continuous methods, so commonplace today, replaced pressure with other physical principles that lead to the separation of oil from the solid part. The extraction system for centrifugation, for example, exploiting the different specific weight of each component, leads first to the separation of pomace and liquid part, and then isolates the oily component from the vegetable water.
Another method, percolation, instead relies on a different surface tension that oil has compared to vegetation water; with the rhythmic immersion of stainless metal sheets in the olive paste, it is progressively collected the liquid that adheres to their surface. With this system, 60-70 % of the oil contained in the olives is extracted. The remainder is separated from the residues of peel and kernels in a centrifugal system, which is followed by a
further centrifugation step to remove the residual vegetation water.
In conclusion, a more or less tight adherence to these operating conditions will consequently determine a more or less high final quality of the product. Today we are witnessing a kind of new Renaissance: the culture of oil, along with that of wine and typical products in general, is posing again together with that of the
Литература
1. Kearney J. Food consumption trends and drivers // Phil. Trans. R. Soc. B.- 2010.- №365.- P. 2793-2807.
2. De Souza R.J., Mente A., Maroleanu A., et al. Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: systematic review and meta-analysis of observational studies / / British Med. J.- 2015.-№351.- P.3978.
3. Alarcon de la Lastra C., Barranco M.D., Motilva V., Herrerias J.M. Mediterranean diet and health: biological importance of olive oil // Curr. Pharm. Des.- 2001.- №7.- P.933-950.
4. Visioli F., Bogani P., Grande S., Galli C., Mediterranean food and health: building human evidence // J. Physiol. Pharmacol.- 2005.-№56 (S1).- P.37.
5. Buckland G., Gonzalez C.A. The role of olive oil in disease prevention: a focus on the recent epidemiological evidence from cohort studies and dietary intervention trials // British J. Nutr.-2015.- №113.- P.S94-101.
6. Parkinson L., Cicerale S. The health benefiting mechanisms of virgin olive oil phenolic compounds // Molecules.- 2016.- №21.-P.1734. DOI: 10.3390/molecules21121734.
7. Rubio-Senent F., B. de Roos, Duthie G., Fernandez-Bolanos J., Rodriguez-Gitierrez G. Inhibitory and synergistic effects of natural olive phenols on human platelet aggregation and lipid peroxidation of microsomes from vitamin E-deficient rats // Eur. J. Nutr.- 2015.- Vol.54, №8.- P.1287-1295.
8. Calabriso N., Scoditti E., Pellegrino M., Carluccio M.A. Olive oil, in The mediterranean diet. An evidence-based approach.- V.R. Preedy, R.R. Watson Eds., Academic Press-Elsevier Publ., 2015.- 135 p.
quality of life, which has its foundation in the rhythms and harmonic tenors, in small-towns, in the return to nature. The hope that we can make is that this is understood and shared by all the actors involved: end users with their appreciation of the quality and health benefits, and producers of consumer goods with the awareness that the fruit of their activities will always find better placement and remuneration in an ever expanding and competitive market.
References
1. Kearney J. [Food consumption trends and drivers]. Phil. Trans. R. Soc. B, 2010, no.365, pp.2793-2807.
2. De Souza R.J., Mente A., Maroleanu A., et al. [Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: systematic review and meta-analysis of observational studies]. British Med. J., 2015, no.351, p.3978.
3. Alarcon de la Lastra C., Barranco M.D., Motilva V., Herrerias J.M. [Mediterranean diet and health: biological importance of olive oil]. Curr. Pharm. Des., 2001, no.7, pp.933-950.
4. Visioli F., Bogani P., Grande S., Galli C., [Mediterranean food and health: building human evidence]. J. Physiol. Pharmacol., 2005, no.56 (S1), p.37.
5. Buckland G., Gonzalez C.A. [The role of olive oil in disease prevention: a focus on the recent epidemiological evidence from cohort studies and dietary intervention trials]. British J. Nutr., 2015, no.113, p.S94-101.
6. Parkinson L., Cicerale S. [The health benefiting mechanisms of virgin olive oil phenolic compounds]. Molecules, 2016, no.21, p.1734. D0I:10.3390/molecules21121734.
7. Rubio-Senent F., B. de Roos, Duthie G., Fernandez-Bolanos J., Rodriguez-Gitierrez G. [Inhibitory and synergistic effects of natural olive phenols on human platelet aggregation and lipid peroxidation of microsomes from vitamin E-deficient rats]. Eur. J. Nutr., 2015, vol.54, no. 8, pp.1287-1295.
8. Calabriso N., Scoditti E., Pellegrino M., Carluccio M.A. [Olive oil, in The mediterranean diet. An evidence-based approach] V.R. Preedy, R.R. Watson Eds., Academic Press-Elsevier Publ., 2015, 135 p.
