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Vous consultezChapter 13. Mediterranean food products: research and development
AuteurDimitrios Boskou du même auteurAristotle University of Thessaloniki, Greece
Dimitrios Boskou graduated in chemistry from Aristotle University of Thessaloniki (Greece), subsequently obtaining a PhD from the University of London (United Kingdom) and the degree of Doctor of Science from Aristotle University. He served as a lecturer, associate professor and professor at Aristotle University from 1970 to 2006 and was a member of the Commission on Oils, Fats and Derivatives of the International Union of Pure and Applied Chemistry (IUPAC) from 1986 to 1998. Since 1995, he has been a member of the European Commission ’s Scientific Committee for Food and an EFSA expert. He has published over 85 papers and reviews, is the author and editor of 6 books, and the lead author of more than 10 chapters in books relating to the chemistry of oils and natural products. He is a contributor to international scientific encyclopedias and the Lexicon of Lipid Nutrition.
The term “Mediterranean Diet” refers to the eating patterns typical of specific regions of the Mediterranean in the early 1960s. It is characterised by an abundance of plant foods such as vegetables, fresh fruits, grains, pasta, bread, pulses, nuts and seeds, and a high level of monounsaturated fatty acids. Olive oil is the principal source of fat and moderate amounts of fish, poultry, dairy products and eggs are consumed along with small amounts of red meat and wine.
2 There has been a growing interest over the past few decades in the role of the Mediterranean Diet in preventing the development of certain diseases, especially cardiovascular disease and certain forms of cancer. Although a traditional diet of the Mediterranean region, it has been garnering interest throughout the world and its reputation is now global. As a result, more and more people are interested in the health benefits it confers.
3 The first findings came from epidemiological studies, but today there are many biochemical and other laboratory studies that confirm these epidemiology findings. The great progress made in the areas of nutrition, bioscience, biochemistry and chemistry of natural products during the last two or three decades has demonstrated that some commonly encountered food constituents have hitherto unknown health/promoting and disease/preventive properties. Food is not just a culinary item but may also be a health aid.
4 Mediterranean food products are now being re-evaluated for the beneficial health effects they offer, effects which go beyond basic nutritional needs. Major developments that aim to improve their quality and preservation therefore focus on improving their composition, mainly on the basis of better retention of bioactive ingredients. This chapter discusses research and innovative food science in the light of increased awareness of the biological importance of Mediterranean food products. It highlights points that may help producers and manufacturers to identify emerging technologies and growth opportunities in the production of agricultural products but also in the food supplement, pharmaceutical and functional food industry. Examples are given indicating how research in the field of food chemistry, food technology, food biochemistry and biosciences can contribute to the promotion of Mediterranean products and the exploitation of agricultural waste products.
5 Governments throughout the world have had very little success in persuading the public to follow a healthy diet. Consumers in Mediterranean countries have been criticised for gradually abandoning the wise rules of their traditional diet. The industry, on the contrary, seems to be responding more favourably and to be taking the rapidly growing number of research studies backing the nutritional importance of the diet seriously into consideration.
6 Only a handful of traditional food products are being exploited commercially to date. Little information is available in the public arena on many products that can claim a truly Mediterranean identity. It must also be stressed that it is not only foods and food products that can be of interest, but also the methods and technology used in the processing. Traditional methods can involve low energy consumption, and this principle paves the way for combining tradition with modern technology. Thus, Mediterranean countries, whose food heritage has not yet been fully exploited on regional or global markets, have a great deal of catching up to do, considering that in recent decades the globalisation of food and agricultural systems has considerably undermined ethnic agricultural traditions.
7 From the point of view of science and technology it is clear that additional knowledge is needed to fully relate scientific knowledge to specific foods, especially those which are key ingredients of the traditional Mediterranean Diet and are rich in antioxidants and phytonutrients. This aspect is clearly demonstrated in the examples given below.
8 Olive oil, a staple food for the people living in the countries surrounding the Mediterranean Basin, is also dominant in the area of specialty foods, while on the issue of good health the news get better and better as more and more research findings confirm previously suggested health benefits.
9 This oil is now gaining popularity among consumers who in the past considered it only as part of an exotic dish. Its popularity is mainly due to epidemiological and other data, which show that olive oil play a positive role in the prevention of certain diseases and in particular of coronary heart disease.
10 Today olive oil is produced in many countries, including areas outside the Mediterranean Basin, in a way that the modern technology used is based on the same principles of traditional processing methods. This mode of production is an important example indicating that technology, innovation and tradition can be combined and can interact to achieve high levels of quality. In 2004 the Food and Drug Administration (FDA) announced the availability of a qualified health claim for monounsaturated fat from olive oil and reduced risk of coronary heart disease (CHD) www. fda. gov/ -dms/ qhcolive/ html ...
suite. According to the FDA, there is evidence suggesting that consumers can reduce their risk of CHD if they consume monounsaturated fat from olive oil and foods containing olive oil rather than foods with a high content of saturated fat, while at the same time they do not increase the total number of calories consumed. However, the biological value of olive oil is most probably due not only to its fatty acid composition but also to the nature and levels of minor constituents (Quiles et al., 2006; Núñez-Córdova et al., 2009; Boskou, 2009).
11 Good quality virgin olive oil is protected by strict European Union regulations and specifications of the International Olive Oil Council and other organisations. These rules are now supported by DNA or chemistry-based fingerprinting for identifying the variety and geographic origin (genuineness and typology). There are numerous reports on the discrimination of olive cultivars using molecular markers (Spaniolas et al., 2008). This additional qualitative and quantitative information provides the industry and the regulators with a new valuable means on which to base the procedures that ensure quality, authenticity and safety.
12 Virgin olive oil is a typical example of a “functional” food because of its fatty acid composition and the presence of minor constituents, mainly phenols, and squalene. Accumulated evidence suggests that the oil may have health benefits that include reducing the risk factors of coronary heart disease, preventing several types of cancer, modifying immune response, reducing inflammation markers and decreasing age-related cognitive decline.
13 Considering the above and other properties, olive oil appears to be a veritable functional food and may provide additional health benefits beyond basic nutritional needs. Efforts to improve its composition therefore now aim mainly to increase the content of bioactive phenols. The change in milling from a 3-phase to a 2-phase system is in line with this aim. Other technological innovations in the olive oil industry are also oriented to preserve minor constituents originally present in the fruit in order to optimise antioxidant phenol ratios while at the same time retaining an acceptable bitter taste. The industry is also trying to improve storage conditions and control oxidation by minimising pro-oxidant factors, since the minor constituents are responsible for the unique flavour of the oil.
14 Another form of olive oil is “cloudy” (veiled) olive oil, which is consumed before full precipitation in the tanks and filtration. It is an emulsion-suspension and can persist for months before full deposition of a residue. Small quantities of cloudy olive oil, the real fresh olive juice, are sold directly from the mills to consumers who consider this type more “green” and richer in flavour. This product is now earning popularity due to findings related to the presence of important phenols, including oleocanthal, and other minor components with pharmacological properties. Oleocanthal, related to the stinging sensation at the back of the throat, was recently synthesised and found to have the same pharmacological properties as the anti-inflammatory drug ibuprofen (Beauchamp et al., 2005).
15 Recent studies indicate that not only virgin olive oil but also olive residue oil (olive pomace oil) may contain biologically important compounds such as oleanolic acid, maslinic acid, ursolic acid and other triterpenes (erythrodiol, uvaol). These compounds were found to be potent antioxidants preventing both the initiation and propagation of Low Density Lipoprotein oxidation and also to have an antitumoral and anti-inflammatory effect. Attempts are now being made to recover these bioactive compounds from olive milling by-products. These efforts indicate that the biological value of residue olive oil must be re-evaluated (Boskou, 2009).
16 In comparison to other vegetable oils, usually richer in polyunsaturated fatty acids, olive oil has a much lower rate of alteration during domestic frying or other uses that require high temperatures. This stability of olive oil and its resistance to high temperatures are due to its fatty acid profile and the presence of natural antioxidants and sterols that inhibit oxidative polymerisation (Boskou, 2006a). However, when the oil is heated for repeated frying operations its phenolic content and the antioxidant activity are significantly diminished. These results demonstrate that virgin olive oil has a remarkable thermal stability, but should not be seen only as a good frying medium. If health effects are expected from the phytochemicals present, the number of heating operations should be restricted to a minimum.
17 The biological importance of olive oil has stimulated the interest of the industry, and today there are patented foods on the market, mainly margarines and cholesterol-lowering products, reduced-fat mayonnaises or chocolate products that contain olive oil. The justification for such products is obviously the result of many studies based on dietary supplementations with olive oil suggesting that the replacement of other fats by olive oil reduces cardiovascular disease and other risks.
18 To obtain better stability of fermented sausages, part of pork fat can be replaced with olive oil. This substitution results in a lower lipid oxidation rate and a better balance of saturated, monounsaturated and polyunsaturated fatty acids. Partial replacement of the animal fat by olive oil has also been suggested for reducing cholesterol levels in meat products. In other cases the nutritional benefits of olive oil are combined with those of n-3 fatty acids (Sacchi et al., 2002).
19 Salad dressings made with olive oil and lemon juice are very popular in the Mediterranean countries. They are a rich source of biologically important compounds such as biophenols, lipid-soluble vitamins, water-soluble vitamins and squalene. Adamantini Paraskevopoulou et al. (2005) have developed a stable olive oil and lemon juice salad dressing using xanthan gum as stabiliser and gum arabic or propylene glycol alginate as emulsifiers. This dressing can be used in convenience foods.
20 There are products on the market (mainly spreads) in which olive oil has been incorporated into their composition. The level of olive oil addition is usually low as is the concentration of olive-oil-derived micronutrients in the final product. Researchers are investigating the incorporation of selected bioactive ingredients of olive oil into modern culinary products in novel forms and in substantial concentrations that may exhibit a long-term beneficial effect. Their efforts are based on low temperature crystallisation that can provide two fractions, with a significant difference in the melting point but with the same oxidation stability (Jansen and Birch, 2009).
21 Olive oil is too valuable to be hydrogenated since even lampante (non-edible) oils are usually more expensive than seed oils. Thus, hydrogenation is meaningful only in the case of surplus of raw material for the production of specific products. Olive oil is not rich in polyunsaturated fatty acids; to obtain a hard product it has to be hydrogenated under conditions that favour positional and geometrical isomerisation. Interesterification of blends of refined olive oil and tristearin produces zero-trans plastic fats with properties similar to those of package margarines and the additional advantage of high amounts of cis monounsaturated fatty acids (Boskou, 2006a).
22 Halil Vural and Issa Javidipour (2004) have prepared interesterified olive oil for use as a beef fat substitute in sausages in order to obtain a better ratio of unsaturated to saturated fatty acids. Other attempts have also been made to use olive oil in the preparation of “structured lipids” (Fomuso et al., 2001; Tynek and Ledechowska, 2005).
23 Recently, Manuel Criado and his collaborators (2007a and 2007b) studied lipase-catalysed interesterification of virgin olive oil and fully hydrogenated palm oil and described the chemical properties of the semi-solid product obtained. Refined olive pomace oil, stearic and palmitic acids were used in a specific lipase-catalysed acidolysis for the production of a cocoa-butter-like fat (Çiftçi et al., 2008).
24 Other innovations relating to the quality of olive oil are concerned with bitterness, the level of polar phenolics, hydrolysis of secoiridoids, pro-oxidative factors and the balance between phenols concentration and the bitter index.
25 Table olives are a highly nutritious food with a balanced content of fats made up mainly of monounsaturated oleic acid. Eating olives also provides fibre, vitamins and minerals. Olives constitute an essential element of the Mediterranean Diet and a featured ingredient in hundreds of dishes. They are important from a nutritional point of view for the general population in many Mediterranean countries, especially during the long periods of fasting. They are of vital importance for the Christian orthodox monks and nuns who consume large quantities of olives. In Portugal, stoned halved table olives, known as “alcaparra”, are widely consumed and their production is an important agro-economic factor for local producers (Soussa et al., 2006).
26 Table olives, if properly debittered, can contribute to the daily intake of nutritional antioxidants. They contain an array of polyphenolic phytochemicals, including hydroxytyrosol, 3,4-dihydroxyphenylglycol, various hydroxytyrosol derivatives (e.g., oleuropein) and flavone glycosides (Boskou, 2006a; Rodriguez et al., 2009; Zoidou et al., 2010).
27 The concentration of oleuropein must be reduced during the table olive elaboration process. The most usual industrial debittering methods consist of treating the fruits with water or a sodium hydroxide solution or leaving them in brine that produce the hydrolysis of this compound.
28 Debittering causes diffusion of phenols from the fruit to the water or brine and vice versa. The prevailing phenols in table olives are hydroxytyrosol, tyrosol, luteolin and phenolic acids (Boskou, 2009). Evagelia Zoidou et al. (2010) identified Throuba Thassos, a traditional table olive variety, as a nutritional rich source of oleuropein.
29 Debittering using existing technologies presents certain drawbacks such as time, discharges and the prohibition of the product thus obtained in the trade of “ecological” olives. New procedures allow removing bitterness of the fruit through phenol oxidation processes. Such innovations may provide competitive advantages as long as olives and olive preparations are not evaluated as sources of natural antioxidants, since oxidation destroys the valuable phenols. In a recent study, Vassilis G. Dourtoglou et al. (2006) examined the effect of the storage of olives under carbon dioxide atmosphere. Such studies may provide new insight into the debittering of olives, which should be seen as valuable sources of natural antioxidants. It must also be stressed that patented innovative processes for producing olive powders or other products used in pizzas, pastas, breads, spreads, dips, dressings, etc. are now based on the retention of health compounds initially present in the olive. Such products are advertised as good sources of hydroxytyrosol, one of the most potent antioxidants found in nature. Another innovative idea is to enrich table olives with phenols extracted from olive leaves in order to restore the phytochemicals lost in the debittering process (Lalas et al., 2011).
30 The carob tree (Ceratonia siliqua L.), is widely distributed in the Mediterranean area. Carob bean or St. John ’s bread, the brown pod of the carob tree, is a fruit rich in carbohydrates that has been used by man for centuries as a source of nutrition. Beyond the traditional consumption of raw carob pods as sweet fruit by Mediterranean people, the use of processed carob husk in confectioneries is well-established. Fine ground carob powder from the carob pulp is used in various industries in the production of confectionery, beverages, bread or pasta. Carob flour, milled from the dried pod is often used as a cocoa substitute. It is caffeine free and low in saturated fat and is thus ideal for those who need to avoid chocolate.
31 The gum which comes from the endosperm of the seed is chemically a polysaccharide, a galactomannan (Additive E 410, a thickener and stabiliser, the preferred gum in frozen desserts, cultured dairy products, cream cheese and other products). It is the best-known example of a co-gelling polysaccharide, which interacts by association with helical polysaccharides like agar-agar. An innovation in the carob bean business is the preparation of a dietary fibre with a unique composition.
32 Tehina (or tahini) is made from sesame seeds. It may contain other ingredients which improve the texture or provide more authentic “Mediterranean” taste. It is often used in the preparation of hummus or other dips and for the preparation of halva, a popular sweet dessert. As a spread, tehina replaces butter on bread. Tehina sauce is a popular condiment for the meat and vegetables in the cuisine of Middle East and Mediterranean countries.
33 Sesame seed, tahini and halva are rich sources of sesamol and important dietary lignans such as sesamin, sesamolin and sesaminol. Sesamolin and sesamol are believed to promote the integrity of body tissues in the presence of oxidising compounds. There is ample literature on the antioxidant and anti-cancer activity of sesame seed and sesame seed oil and their various healthful properties (Boskou, 2006b; Moazzami et al., 2007). The latter would justify a greater awareness of sesame-based foods, but for the moment tehina and halva seem to be awaiting wider recognition.
34 Sesame seed oil is very stable at high temperatures. The stability has been attributed to tocopherols, ethylidene side chain sterols, sesamol and lignans (Boskou and Elmadfa, 2010). This stability explains the use of sesame seed in the preparation of “healthier” frying oils.
35 Hummus is one of the world ’s oldest foods; there is evidence suggesting that the ancient Egyptians used chickpeas 7,000 years ago and that active cultivation in the Mediterranean basin began around 5,000 years ago. The nutritional value of traditional hummus is due mainly to the chief ingredient, chickpeas. Other contributing ingredients are olive oil, lemon juice, tahini, (sesame seed paste) and spices. Hummus may also contain spinach, garlic, red peppers, olives or other ingredients, which provide distinctive flavours. The addition of olive oil, olives and tehina impart significant health benefits such as high monounsaturated fatty acid content and high content of biologically important phenols. Hummus is a good source of soluble fibres, which may help to lower cholesterol by “capturing” the cholesterol and “dragging” it away from the intestines. Made popular by the Mediterranean Diet, hummus is a healthy alternative spread and is rapidly becoming a staple in many United States diets.
36 Prevailing theories in the field of modern nutrition indicate that one of the keys to staying healthy is to stock up on antioxidants, which promote healthy ageing in every system of the body. This is one of the most important reasons why a Mediterranean Diet, with its high fresh fruit and vegetable content, is recommended.
37 Based on this theory and the fact that most consumers do not get the necessary nutrient intake needed daily, the industry ? mainly in Western countries ? produces Mediterranean vegetable blends in concentrated forms that resemble the antioxidant-rich Mediterranean Diet. Theoretically, consumers living in the Mediterranean countries do not need such supplements, because they are supposed to obtain the necessary intake. This is not true, however, since people living in the Mediterranean basin, especially in the Northern Mediterranean countries, have abandoned their healthy traditional habits and consume too much fat and red meat; their diet is far from the suggested daily intake of five to seven servings of fruit and vegetables.
38 In a very recent study (Ganhão et al., 2010) wild Mediterranean fruits such as dog rose (Rosa canina L.), strawberry tree (Arbutus unedo L.), common hawthorn (Crataegus monogyna L.) elm-leaf blackberry (Rubus ulmifolius Schott) were analysed for the level and profile of phenolic compounds and the in vitro antioxidant activity. Extracts from these fruits were tested as inhibitors of lipid oxidation in raw pork burger patties. The intense antioxidant activity found, compared to that of quercetin, marks the potential use of these fruits as ingredients for the manufacturing of healthy meat products.
39 Studies of this nature indicate how recent research opens up new avenues for exploiting Mediterranean plants, which are rich sources of natural antioxidants. Antioxidant-enriched fruit varieties can be selected by means of specific breeding programmes. The availability of high quality and nutritionally enriched fruits at competitive costs may be a useful tool in the planning of healthy diets.
40 Traditional dried fruits such as raisins, figs, dates, apricots and apples have been a staple of Mediterranean Diets for millennia. Dried fruits are a particularly significant source of dietary fibre and potassium. They also provide essential nutrients that are otherwise low in today ’s diets, such as vitamin A (apricots and peaches), calcium (figs), vitamin K (prunes), iron, copper and boron (raisins, prunes). Dried fruits are an excellent source of polyphenols and phenolic acids. These compounds make up the largest group of phytochemicals in the diet and appear to be partly responsible for the potential health benefits attributed to diets rich in fruits and vegetables. Various dried fruits have unique phenolic profiles. For example, the most abundant in raisins are the flavonols quercetin and kaempferol and the phenolic acids caftaric and coutaric acid. Dates contain quercetin, apigenin and luteolin; prunes have a very high chlorogenic acid content. Dried apricots and peaches are also important sources of carotenoids, compounds which are precursors of vitamin A and antioxidants.
41 Many companies claim that the existing studies and extensive scientific documentation related to the biological properties of biophenols and other phytochemicals present in olive tree products justify and support the positioning of various preparations in the market of phytopharmaceuticals, dietary supplements, functional foods and herbal teas.
42 There is a wide range of patented and standardised olive fruit and olive leaf extracts in the form of syrups or pills, sold mainly in the so-called health ingredients stores or health shops. They are continuously introduced on the market by those who wish to capitalise on the increasing awareness of the benefits of the Mediterranean Diet. Their main characteristic is the high level of oleuropein and other biologically important phenols such as hydroxytyrosol and verbascoside, all of them responsible for many of the biochemical and biological effects of the extracts. Some products are mixtures with other antioxidants such as carotenoids, vitamin C, tocopherols and extracts from Lamiaceae plants.
43 One of the most active chemicals found in olives and olive leaves is oleuropein; a natural chemical compound widely studied for its health related effects (Boskou, 2009). Chemically, it is a glucoside ester of hydroxytyrosol and elenolic acid.
44 Oleuropein has the following properties: antimicrobial activity, high antioxidant activity, scavenging of superoxide radical and other reactive species, inhibition of LDL oxidation and many others; there are also claims that it may contribute to the prevention of hypertension, osteoporosis and cancer.
45 Concentrates of oleuropein are widespread on the market and they are mainly prepared by extraction from olive leaves (for a review see Boskou, 2009). Also, extracts rich in polyphenols, as well as high-purity oleuropein have been obtained by “alkaline extraction” from the leaves of the olive tree (Kefalas, 2007).
46 Oleuropein concentrates are found on the market in the form of capsules or syrups. They are used mainly in what is known as holistic medicine to treat conditions such as influenza, herpes and various infections. For the moment such preparations should be used carefully since they may have interactions with blood-pressure-lowering or sugar-lowering drugs, but this is a general problem of interaction between herbal products and medications and it is essential to inform one ’s doctor of the herbal preparations one is taking.
47 Olive-derived hydroxytyrosol preparations are distributed in many parts of the world and marketed as products added to health supplements and foods related to the Mediterranean lifestyle.
48 Hydroxytyrosol can be produced by various patented or other proposed processes from olive milling waste-water. It is claimed that it offers remarkably high free-radical protection. The methodology of obtaining extracts rich in polar phenols is based on the defatting of oil mill wastewater, extraction with organic solvents and fractionation using various methods (for a review see Boskou, 2006a). Production of highly purified hydroxytyrosol can be obtained from “alperujo”, the liquid-solid waste product of the two-phase olive processing system. Ines Fki and his collaborators (2005) have proposed an ethyl acetate extraction procedure for mill wastewater using a counter-current unit. Other patented techniques propose the extraction of pitted olives in order to obtain hydrolysis products from oleuropein.
49 Olive leaves have been used medicinally in various times and places. Natural olive leaf and olive leaf extracts are now marketed as anti-aging, immunostimulators and even antibiotics. Clinical evidence has proved the blood-pressure-lowering effects of carefully extracted olive leaf extracts. Bioassays support its antibacterial, antifungal and anti-inflammatory effects at the laboratory level. A liquid extract made directly from fresh leaves recently attracted international attention when it was shown to have an antioxidant capacity almost double that of green tea extract and 400% higher than vitamin C.
50 Squalene is an intermediate in the biosynthesis of sterols in plants and animals, a precursor of phytosterols in plants and a precursor of cholesterol in humans. It occurs in high concentrations in the liver oil of certain sharks and in smaller amounts in olive oil, rice bran oil and yeast.
51 The two more important sources of squalene are shark liver oil and the deodorisation distillates of the olive oil refining process (squalene accounts for more than 50% of the unsaponifiable matter of olive oil). Squalene supplements are regarded as a promising anti-cancer agent, although human trials have yet to be performed which could verify its usefulness in cancer therapy. Researchers believe that squalene is a constituent that has a significant contribution to the health effects of the oil.
52 The possibility of using chopped and deseeded carob pods as a source of polyphenolic antioxidants has been discussed by Dimitris P. Makris and Panagiotis Kefalas (2004). Maximum quantities of polyphenolic components were found in 80% acetone extracts.
53 Grape seeds are vinification by-products that have a high concentration of flavonoids. They are a low-cost commercial source for extracting phytochemicals. The compounds identified and quantified in grape seeds are gallic acid, catechin, epicatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate and procyanidins. Grape seed extract may be useful for treating high blood pressure and high cholesterol. Resveratrol is a polyphenol contained in grape seeds, which may interfere with cancer cell growth and proliferation. In laboratory models, preliminary research shows that grape seed extract may have other possible anti-disease properties, such as wound healing and enhancement of bone density.
54 Pomegranate (Punica granatum) features prominently in the diets and history of people living in the Mediterranean region. It has been cultivated since prehistoric times and is common around the Mediterranean shores. It contains a broad spectrum of vitamins and minerals, with high amounts of vitamin C and potassium. It is also a powerful source of antioxidant polyphenols (delphinidin, cyanidin and pelargonidin glucosides) and anti-inflammatory essential amino acids. Recent science has been focusing on the antioxidant and cardioprotective aspects of pomegranate. These brightly coloured fruits contain numerous compounds known for their antioxidant capabilities, including anthocyanidins, catechins, proanthocyanidins, ellagitannins, gallotannins, ellagic acid and gallic acid.
55 The by-products of citrus processing are a rich source of naturally occurring flavonoids. The peel has a high concentration of flavonoids. Hesperidin, a flavanone glycoside, is the most important in the citrus peel molasses. Other flavonoids present are flavones and flavonols. Hesperidin is an important bioflavonoid contributing in human nutrition to the integrity of the blood vessels. It is a strong antioxidant providing cellular protection against damaging effects induced by reactive species. Studies conducted with orange peel from oranges cultivated in the Mediterranean region indicated that this by-product is a good source for recovering antioxidants, especially hesperidin (Boskou, 2006b; Kanaze et al., 2009).
56 Corchorus olitorius L. (Molokhiya or Melokhiya) is a vegetable native to Egypt, very popular in Middle Eastern and Mediterranean regions. This vegetable contains calcium, carotene, minerals, vitamin A, B1 and B2. It is a very nutritious and healthy vegetable. Young green leaves and shoots of this fast-growing vegetable are picked for use in cooking. They add flavour and viscous texture to soups and stews, the seeds are used as a flavouring, and a herbal tea is made from the dried leaves. Five phenolic compounds, caffeoylquinic acid and quercetin derivatives, have been identified in the leaves of Corchorus olitorius L. (Azuma et al., 1999). These polyphenolic compounds are now being investigated for their association with the reduction of diet-induced obesity (Wang et al., 2011).
57 Fennel (Foeniculum vulgare) is a plant species in the genus Foeniculum. It is generally considered indigenous to the shores of the Mediterranean, but has become widely naturalised in many parts of the world. It is a highly aromatic and flavourful herb with culinary and medicinal uses. The aqueous extract of fennel contains caffeic acid derivatives and flavonol glycosides, and has a remarkable radical scavenging capacity (Parejo et al., 2004).
58 Kumquat (Fortunella margarita) peel fractions have been studied by Engy Samih Sadek et al. (2009) for their polyphenolic composition and antioxidant characteristics in the framework of research on bioactive phytochemicals in native species of the Mediterranean basin.
59 The investigations discussed above are good examples of innovative food science and indicate emerging technologies. Efforts are increasing to obtain foods with higher nutritional value by adding specific compounds that are only present in small amounts or are not present at all.
60 The industry ? but also researchers ? believe that awareness of the Mediterranean Diet is expected to boost sales of various preparations based on bioactive ingredients obtained from olive oil and olive tree products, which can be used for functionalising food (for a review see Boskou, 2009).
61 Food compositions fortified with anti-oxidants from olive oil or olives have been proposed for spreads, tomato products and dressings. The principle of the method is to expose olive oil under hydrolytic conditions to an aqueous phase so that lipophilic phenolic compounds will hydrolyse and migrate to that phase. Other attempts aim to obtain more lipophilic derivatives, which are more effective. Various esters of hydroxytyrosol have been prepared and tested for their radical scavenging activity and protection against H2O2-induced oxidative DNA damage.
62 A number of reports have been published recently indicating that research is being carried out to prepare olive oil imitation products. The principle is to use refined high oleic acid sunflower oil to which olive oil phenols such as hydroxytyrosol, oleuropein, luteolin and others have been added in various concentrations. These imitation products are already being advertised as revolutionary products in functional nutrition. It appears that the door is open to enrichment of any oil or food preparation with olive oil phenols. This approach, however, does not seem to be properly documented. Olive oil is a fruit juice with a very complex composition, and many constituents probably have a synergistic effect. It is not yet possible for the time being to fully evaluate the role of the biologically active compounds present in olive oil and to determine the extent of the contribution of each active compound to the overall positive health effect. Besides, as the experts emphasise, phenolic-enriched products should as far as possible approximate the natural environment in which active molecules are found, since such molecules may be not useful outside the original matrix.
63 Present studies aim to find fast, economical and feasible ways to extract antioxidant phenolics from artichoke and use them as possible ingredients for functionalising foodstuffs in order to decrease lipid oxidation and to increase health-promoting properties (Llorach et al., 2002).
64 The dietary fibre from carob ranks favourably amongst the various dietary fibres due to its high lignin and polyphenol content. It combines a digestion-promoting effect with antioxidant potency and a favourable effect on cholesterol absorption. It can be added to bakery products, extrusion products, bars, dairy products and chocolate desserts.
65 Most approved antioxidants added to foods are synthetic. Antioxidants isolated from plant sources may provide alternatives to the current choices of effective oxidation inhibitors but for the moment there are few applications. These few applications and the results of studies conducted in the last two decades provide evidence that deeper insight into the structure-reactivity relationships and proper formulation of antioxidants and synergists could provide a real alternative to hydrogenation or other stabilisation methods. Novel natural antioxidants seem to be the landmark for future exploration in the search for healthier, more stable frying oils.
66 The most important innovative proposals for preventing the deterioration of edible oils during storage or heating are those based on the use of extracts from herbs, especially those of the Lamiaceae family, (oregano, rosemary, and others), which are widespread in the Mediterranean countries. These herbs are very rich in phenolic antioxidants (Boskou, 2006b).
67 Olive leaf extracts have also been suggested in a series of reports as a means of supplementing the nutritional value of frying oils (Farag et al., 2006; Salta et al., 2007).
68 Convincing scientific evidence suggests that the benefits of phytochemicals may be even greater than is currently understood, since they affect metabolic pathways and cellular reactions believed to be involved in the etiology of a wide range of chronic diseases. An increasing number of food scientists are attributing an important nutritional role to the secondary plant ingredients from fruits and vegetables.
69 The Mediterranean Diet, rich in cereals, fruits, vegetables, nuts, whole grains, fish and olive oil is the traditional diet of the Mediterranean region but it has garnered interest throughout the world for the health benefits it can offer. Thanks to this global reputation the food industry has adopted some of its principles to assist in the marketing of healthy foods. This offers new opportunities in the Mediterranean countries to exploit further products, whose health ingredients have not yet been fully utilised by the industry and whose important benefits are not yet known to consumers. Bioscientists will soon indicate more clearly where the impact on health lies and what the real bioavailability of bioactive compounds and their possible synergies are. The changes needed to remedy the mismatch between previous dietary habits and present-day lifestyles are becoming more visible every day.
70 The findings in the areas of food science and biosciences call for new processing techniques based on food science and technology, which meet quality, identity and safety requirements. Alternative uses of traditional ethnic products and the process to obtain a Hazard Analysis Critical Control Point certification are very good examples in this context.
71 Consumer interest in food products linked to geographical origin and traditions in the Mediterranean has been growing in recent years. However, with a few exceptions, the specific quality that is sought is not always properly documented by research work, especially analytical work indicating the typicality of such products. Producers should indicate more clearly how composition and properties are connected with specific geographical indications and should convince consumers that this distinction is based not only on the administrative division of certain production areas, but on the genuine preservation of traditional quality and local know-how (that guarantees intrinsic factors such as colour, flavour, appearance, composition, etc.). With increasing urbanisation, origin is becoming increasingly important, and it must become a “proxy”, promoting consumer confidence.
72 Research and development are important tools for innovation, productivity growth and competitiveness. Research and development means an increase in knowledge and use of the knowledge stock to devise new applications. Today, most of the scientific evidence is available, while new research work supporting the Mediterranean Diet and Mediterranean food products is continuously being produced. However, the exploitation of this knowledge in order to develop particular technologies for rural development is not satisfactory. In spite of many joint research projects and public or other subsidies, the R&D alliance is not as yet recognised as being particularly effective. There is generally a gap amongst actors, mainly between researchers and industry and between researchers and producers. The results of the firms that innovate in-house are more visible. However, there are cases where at least two actors, university laboratories and private companies (usually SMEs) collaborate successfully to create products that are innovative and also traditional. This is indicated in the example given in the Box below. There are many other good ideas still pending implementation or still at the experimental stage, such as traditional recipes for sauces adjusted to modern lifestyles, products from antiquity (retro-innovation) such as mixtures of honey and vinegar (the ancient Greek balsamico), low-fat or modified-fat dairy products, mustards and pâtés fortified with novel antioxidants from plant sources, free-flowing granules from olives or olive oil and many other trendy, innovative, yet traditional products obtained with modified technologies that also take sustainability and environmental protection into consideration.
An innovative food product linked to geographical origin and traditions in the Mediterranean (from emerging science to in-house innovation)
A small enterprise on a Greek island processes a certain variety of olives, which are partly debittered on the tree. The trees are cultivated biologically, and the olives are processed following a traditional method based on the use of dry salt. An innovative method of debittering reduces salt content to a minimum. The product, certified as a product of geographical origin, can be packed in vacuum and offered on the market as a snack, transforming the use of olives from an appetiser or an added ingredient in a dish to a healthy snack (dry product, absence of liquids that make it difficult to consume immediately). The packed olives have superior nutritional value, as they are a very rich source of oleuropein, an important biologically active compound. An innovative yet very traditional product.
73 In addition to difficulties such as the lack of close alignment between food research centres and industry and the low return on the investments and profits of the companies that invest in more innovative activities, there are also problems related to consumers. These are conservatism, complex legislation and information concerning product safety. In the past few decades new ideas and new concepts have been introduced in food production concerning traceability, labelling, quality, organic agriculture, sustainability and environmental protection. The consumers see labels such as organic or protected designation of origin (PDO), certified etc., but they need more time to consider them. As the result of these new concepts and consumer patterns tending increasingly towards convenience and service models characterised by the mass production of industrialised products (driven by the ever-growing number of hyper- and supermarkets), there is a great deal of confusion. It is therefore imperative to inform and educate consumers more effectively: they should understand how modern catering can coexist with traditional cooking. It is also important that the scientific knowledge that has been obtained is conveyed to consumers in simple terms so that is can be readily assimilated and that both intrinsic and extrinsic factors are well understood. But most important, consumers should have a better understanding of how findings in the area of chemistry, nutrition and biosciences are connected with specific Mediterranean foods. Analysis of cases of failure and good ideas for innovative products that have been rejected have revealed that the failure was not due to lack of skills or budgetary problems, but mainly to the lack of alignment and the inability of consumers to understand the impact on health. Obviously, better dissemination of the knowledge relating to the scientific advantages of the Mediterranean Diet for health and lifestyle is needed.
74 Mediterranean food products are now being re-evaluated for the beneficial health effects they offer, effects which go beyond basic nutritional needs. Today, much scientific evidence is available, while new research findings supporting the Mediterranean Diet and Mediterranean food products are continuously being produced.
75 Innovative food science is based on increased awareness of the biological importance of Mediterranean products. Major technological developments aiming to improve quality and preservation are therefore focusing on improving composition and retaining bioactive ingredients in the final product. Another innovation is the incorporation of Mediterranean food, phytochemicals and novel antioxidants into other foods. More documentation is needed, however, on patented products containing bioactive ingredients that have been synthesised or obtained from Mediterranean food sources or by processing wastes. Such compounds are used in so-called “health and wellness” supplements, with claims that are not strictly controlled.
76 Since it is to be predicted that within a few years diet will come to be associated with hundreds of “healthier” products, measures must be taken to promote consumer awareness. Consumers should be encouraged to value the cultural identity of food. People should also be in a position to make a more informed evaluation of new products that are both innovative and traditional and can contribute to rural development and prosperity. If the industry and food producers identify this key trend as a driver for innovation and the development of new products, then traditional diets can be easily preserved and revitalised despite changes in consumer demographics and lifestyle.
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PLAN DE L'ARTICLE
- Mediterranean food products
- Health and wellness preparations based on Mediterranean products and by-products
- The functionalisation of food
- Novel antioxidants from herbs and plant extracts
- Research and development
POUR CITER CET ARTICLE
Dimitrios Boskou « Chapter 13. Mediterranean food products: research and development », in MediTERRA 2012 (english), Presses de Sciences Po, 2012, p. 265-282.
URL : www.cairn.info/mediterra-2012-english--9782724612486-page-265.htm.