TRADITIONAL FOOD IN SERBIA : SOURCES , RECIPES AND FATTY ACIDS PROFILES

Traditional foods play a major role in traditions of different cultures and regions for thousands of years while preparation methods of traditional foods are part of the folklore of a country or a region. This paper presents recipes and fatty acid profiles of selected commonly consumed traditional foods in Serbia. The obtained fatty acid composition data are used for making conclusions about meals which are commonly consumed in Serbia. Traditional Serbian dairy products, cheese and kajmak, contained 70% SFAs (mostly palmitic acid). Commonly used meal in Serbian cuisine, prebranac, also contained palmitic acid and oleic acid (38.67% and 35.58% respectively), while linoleic acid was presented with 17.34%, similarly to vanilice. Ajvar, frequently used as a salad, is rich in linoleic acid (49.12%) but less rich in palmitic acid. Trans fatty acids were found in very small amounts in all foods.


INTRODUCTION
Most people can name at least one traditional food of the region they come from.The internet search for "traditional food" shows that numerous collections of traditional food recipes are available worldwide.
Traditional food is a food with a specific feature or features which distinguish it clearly from other similar products of the same category in terms of the use of "traditional ingredients" (raw material of primary products) or "traditional composition" or "traditional type of production and /or processing method" (Costa, 2005).
Traditional foods have been influenced by many factors, such as the availability of raw materials and therefore in countries without the access to the sea the availability of fish and seafood is usually lower than in countries with a large coastal area (Davis, 2005).Moreover, traditional foods and dishes have been influenced by religious habits (Parasecoli, 2005).
Average daily energy requirements are significantly lower than in past centuries (Trichopoulou et al., 2006).Although developed a long time ago, numerous traditional foods, have place in healthy diet today.Some of them may not meet nowadays nutritional needs, because they are energy dense food or possess a high fat content.It makes sense to modify the nutrient composition of some traditional foods to make them more appropriate for the nutritional needs in the 21 st century.
The aims of our study were: 1) to present a recipes of Serbian traditional food 2) to determine fatty acid composition of tradi-tional food 3) to discuss health effects of Serbian traditional food in relation to obtained results.

MATERIALS AND METHODS
Some of commonly consumed Serbian traditional foods was identified as follows: gibanica (filo pastry with cheese fill), prebranac (first cooked, than baked beans), ajvar (cooked pepper and eggplant spread), fresh cheese, kajmak (creamy dairy product), and vanilice (cookies).
Fresh cheese, kajmak and ajvar were purchased from three different producers, 100 g of each were pooled and 200 g of representative sample was taken for further analysis.Gibanica, vanilice and prebranac were prepared using the most common recipes given bellow.Sunflower oil was replaced with flaxseed oil or some other oil rich in omega-3 (n-3) fatty acids.
Ajvar is a mixture of roasted sweet pepper and eggplant, which could be mashed or left chunky, and served as a relish or spread.
Prebranac was prepared from cooked beans, stewed leek and onions, with the addition of ground red paprika powder, salt and pepper.Combined ingredients were baked in oven for 30 min.
Kajmak should be made by boiling unpasteurized, unhomogenized (raw) cow or sheep milk and skimming off the cream that rises on the top.If left to ferment and ripen, aged kajmak has a stronger taste and is yellow in color.
Serbian cheese is usually made from unpasteurized cow's milk.The formed young curd is pressed into flat disc, then the cheese is left to dry on the open air.The surface is rubbed and salted several times over next few days and finally, product is stored in wooden container in brine.The taste of the cheese is slightly sour and salty.
Gibanica is made of sheets of phyllo, eggs, oil, cheese, kajmak, sparkling water and milk.Mixture of ingredients should be placed over the sheet of phyllo in layers and baked in the oven until golden brown.
Vanilice are traditional cookies usually prepared from a dough obtained by mixing pork fat, eggs, flour, salt, ground wallnuts ang vinegar.Form a dough into a 1 cm thick layer, cut out the cookies in a round shape and bake them at 180 °C for 15 minutes.The obtained cookies should be filled with apricot jam and combined to form a sandwich-like shape followed by coating in sugar.

Analysis of fatty acids in traditional food
Fat was extracted according to method of Folche et al. (1957).Ten milligrams of Serbian cheese, kajmak, gibanica, vanilice, prebranac and ajvar, and 2.5 mL of chloroform, 1.25 mL of methanol with BHT (butylated hydroxytoluene) were mixed and homogenized.Chloroform (3.75 mL), methanol (5 mL) and water (0.45 mL) were added in samples which were left overnight in the freezer.Obtained lipid extracts were filtered and evaporated to dryness.Lipid dry residues were dissolved in 2 mL of chloroform-methanol (1:1, v/v) and transferred to test tubes for methyltion by adding 0.2 mL of 2M NaOH in methanol and 1.5 mL of hexane into 0.2 mL lipid extracts and heated at 85 °C for 1 hour.Addition of 0.2 mL of 1M H 2 SO 4 in methanol and heating 2 hours at 85° C finished methylation.Cooled tubes were centrifuged for 15 min, and the hexane layer was transferred into a clear vial.

GCanalysis
Separations of the methyl esters were carried out using a gas chromatograph (Shimadzu 2014; Kyoto, Japan), equipped with a split/splitless injector and a flame ionization detector.The methyl ester separation was carried out on capillary column RESTEK RTX 2330 (60 m, 0.25 mm i.d., 0.20 μm df; RESTEK US, Bellefonte, PA) using helium as the carrier gas.The injector and detector temperature was set at 220 ºC and 260 ºC, respectively.The injecttion was performed in split mode with 1:100 split-ratios.The temperature of the column was initially set at 140 ºC for 5 min, and then increased to 210 ºC at the rate of 3 ºC/min, and held at this temperature for 20 min.Each fatty acid (FA) was identified with reference to the retention time of that FA in standard PUFA-2 (Sigma-Aldrich, St. Louis, MO).The content of FA was expressed as percentage of total FAs.

RESULTS AND DISCUSSION
The results of fatty acid composition, total saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids of traditional foods in Serbia are shown in Table 1.T The commonly consumed cow cheese consists of about 70% of SFAs, and among them the most abundant are palmitic (36.57%), miristic (12.69%) and stearic (8.73%).In addition, cow cheese has high content of oleic acid (22.18%), while other FAs including 18:1, trans is present in a small percentage.Similar FAs composition was found in kajmak (Table 1).
Unlike Serbian cheese and kajmak, gibanica contained high percentage of oleic acid (31.94%), slightly lower percentage of palmitic (25.54%) and linoleic acid (13.08%).The content of the most atherogenic, myristic acid, in gibanica was 7.37%, while the content of stearic acid was similar as in cheese and kajmak.Trans FAs were not detected in gibanica, while the other of FAs were present in less than 2%.Oleic and palmitic acid were found to be the most abundant in vanilice (26.54% and 23.17% respectively), whereas linoleic acid was present with 13.51%.Most abundant FAs in prebranac were palmitic and oleic acid (38.67% and 35.58% respectively), while linoleic acid was present with 17.34%.Other FAs were present in low amounts.On the other hand, ajvar was rich in linoleic (49.12%), oleic (25.51%) and palmitic acid (15.68%).Vessby, 2001).Thus, we recommend a lower intake of cheese and kajmak and increased intake of olive oil.Also, the food technology, which modifies the FAs profile of foods naturally rich in SFAs in favors of oleic acid, is recommended to be used.The predominant FAs in gibanica were SFAs, similar to cheese and kajmak, but the content of MUFAs was higher.Dominant FAs in prebranac were palmitic and oleic acid.High intake of palmitic acid contributes to the development of cardio-vascular diseases (Haug et al., 2007).Ajvar mostly contained linoleic and oleic acids.Mammals are unable to synthesize linoleic acid, which is a precursor of omega-6 (n-6) FAs, thus it must be provided by food intake.In the last 50 years, the consumption of n-6 FAs has substantially increased, whereas the intake of omega-3 (n-3) FAs has decreased (Simopoulos et al., 1999).Increased consumption of food with high n-6 PUFAs content increases n-6/n-3 ratio, which leads to thrombosis and inflammatory reactions.Opposite, high n-3/n-6 ratio has cardio protective, antithrombotic and anti-inflammatory properties (Lenas et al., 2011).
According to Trichopoulou et al. (2007), dietary patterns are influenced by the local availability of foods and the cultural and socioeconomic environment, but there is a trend for transfer and assimilation of new habits between countries.In the 1960's, the diet of Mediterranean populations was characterized by a high consumption of fruits and vegetables, contrary to the low consumption of these foods in northern European countries.These differences seem to be diminishing.Contemporary patterns reveal that the Mediterranean population is straying from their traditional dietary choices, whereas Mediterraneanstyle eating gains popularity in northern European countries (Trichopoulou et al., 2006).

CONCLUSION
Commonly consumed traditional food in Serbia is rich in SFAs, mostly palmitic and mirystic acids, which are known as atherogenic.On the other hand, high content of oleic acid, known as anti-inflammatory and anti-tumor, was found in gibanica, while high content of linoleic acid was found in ajvar.

Table 1 .
Fatty acids composition (%, w/w) of traditional foods in Serbia Serbian cheese and kajmak are daily consumed.
N.D.-not detected; Results are presented as percentage (average±SD) of fatty acids of total lipids; SFA-saturated fatty acids; MUFA-monounsaturated fatty acids; PUFA-polyunsaturated fatty acids Among the other traditional food,