EFFECTS OF SOME EDIBLE OILS ON BLOOD COMPOSITION IN EXPERIMENTAL ANIMALS

The present work aims to study the potential effect of edible oils like olive, sunflower and flaxseed oils to give more protection against harmful effect of frying oil used in preparation of Tamiya (Falafel). Chemical and physical properties of oils were determined , also fatty acids composition of oils were identified . To study the harmful effect of oils used in preparation of falafel , twenty five of male albino rats were used over 45 days period. The animals were divided into (5) groups, wherein groups number (1) represent control which were fed on basal diet, while group number (2) was received 15% frying oil . Other three groups allowed to feed on high 15% frying oil with olive oil (5%) group number (3) , sunflower oil (5%) group numer (4) and flaxseed oil (5%) group number (5). At the end of the experimental period, blood samples were collected to determine lipid profile include triglyceride , total cholesterol , HDLcholesterol and LDL cholesterol. The kidney functions include urea nitrogen and creatinine. From the obtained results , it concluded that group of rats fed on 15% frying oil were considered as a major risk factor for hyperlipidemia disease. The obtained results could be summarized that edible oils like olive oil , sunflower oil and flaxseed oil were considered the best for causing a reduction of TC, TG and LDL . Also, kidney function has been improved and there were a significant reduction urea than that of positive control group. Key wards: Frying oils – Edible oils – Triglycerides Cholesterol – kidney functions . INTRODUCTION Tamiya (Falafel) is the most popular fried food product used by almost all Egyptians. It is a cheap, easily and quickly prepared, taste full and has a quite national value. Preparation of Tamiya in frying pastes contain broad bean , garlic , onion, Egyptian leek and spiced minced and frying in edible oil. Longtime and deep boiling of edible oil during the frying process gives to formation of free radicals and other harmful agents . Frying is one of the oldest and simplest methods of food cooking, and it remains very popular. Frying involves putting food in contact with hot oil for various periods of time to withdraw the thermal energy and cook the food as mentioned by Rossell (2001). No matter where or when frying originated, it remains a cooking method widely used domestically, commercially and industrially as mentioned by Chapman (2012). Frying is fast, generates unique flavors and textures which cannot be created by other means, and can be accomplished with simple equipment as mentioned by Rossell (2001). The frying of food can be performed in a variety of ways such as pan frying, deep fat frying, stir frying, and sauteing. Each type of frying can be modified to suit the needs of the individuals carrying out the frying process. Deep fat frying is an important food preparation process in the food industry because it is fast, convenient, and produces highly accepted foods amongst consumers. Unique properties of fats and oils provide a distinctive flavor, odor, and pleasing mouth-feel to M. A. Habieb, et al., 20 fry food products as mentioned by Orthoefer et. al, (2006a). Due to oxygen absorption from the oilair interface, leaching of food components, and the breakdown of oil constituents, a mixture of hundreds of chemical components is formed. The rapidly degrading frying oil can produce compounds that reduce oil quality, be absorbed by the fried food to create offflavors, and cause a decrease in the nutritional value of the fried food as mentioned by Orthoefer et. al, (2006b). This can potentially become hazardous as highly oxidized oils have been linked to deleterious health effects in mice causing weight loss, liver and kidney damage, and intestinal tumours as mentioned by Paul et al., (1997) and Stier, (2001). Three major types of reactions have been documented during frying: hydrolysis, oxidation and polymerization. Hydrolysis of ester bonds due to the moisture introduced by foods releases long-chain free fatty acids. Oxidation takes place due to the presence of air, and dimers and polymers are formed by radical recombination to form -C-C-, -COC-, and -C-O-O-Cbonds as mentioned by Sahin, and Sumnu (2009) , Gupta (2005) . The first health concern is the use of saturated frying oils such as animal fats. Saturated fats have been proven to increase low-density cholesterol (LDL) and reduce highdensity cholesterol (HDL) as mentioned by Bockisch (1998). The changes in cholesterol level will promote the risk of cardiovascular disease such as hypertension, heart attack and stroke. Although initial studies focused on the overall Mediterranean diet, more recent studies compare a diet rich in olive oil to one low in olive oil. These studies provided a good evidence olive oil may be beneficial for reducing high blood pressure and preventing breast and colon cancer. In vitro studies have been designed to identify how olive oil exerts its effects at the cellular level. The antioxidant capacity of olive oil contributes to many of its health benefits. The antioxidant action of olive oil in vitro has been highly documented and linked to such benefits as chemoprotection, anti-inflammatory action, and prevention of atherosclerotic plaque formation. as mentioned by Emily et al., (2007). Flaxseed oil or blends of flaxseed oil and sunflower oil promoted cholesterol reduction in hypercholesterolemic rats as compared to diets formulated with hard fats. These authors suggested that a diet with the appropriate balance of n-6 and n3 fatty acids was preferred over diets high in n-6 fatty acids Ranhotra et al. (1992). Ground flaxseed is high in omega3 fatty acids which have been shown to reduce hypertension, cholesterol and triglyceride level Oomah and Maza, (1998). Sunflower oil is very high in polyunsaturated fatty acids and ranges between 64 and 68 percent. From a nutritional standpoint, this is desirable, because polyunsaturates are the source of essential fatty acids necessary for the production of prostaglandins. Prostaglandins play major roles in protecting the cardiovascular, reproductive, and immune and central nervous system Madhavi et al., (2010). MATERIALS AND METHODS Materials: The olive oil, sunflower oil and flaxseed oil samples were collected from local market. Tamiya boiled oil was collected from 3 different restaurants in Shebin El-Kom city, El-Minufia Governorates randomly. Effects of some edible oils on blood composition in experimental ............... 21 Methods : Physico-chemical properties of the oils: The physico-chemical properties (saponification value, acid value, ester number, peroxide value, iodine value , specific gravity, viscosity and refractive index).of the oil were carried out using the method described by (A.O.A.C 1990). Identification of fatty acids: Saturated, unsaturated and total fatty acids were determinated in the oil by using methyl esters boron trifluoride method A.O.A.C (2012) , the oil is saponified with sodium hydroxide in methanol .The fatty acids are methylised with boron tri fluoride in methanol, extracted with heptanes and determined on a gas chromatograph with FID detector (PE auto system XL) with auto sampler and Ezchrom integration system. Carrier gas (He), ca.25 Psi –air 450 ml/min –Hudrogen 45 ml – split 10 ml/min. oven temperature 200 ◦ C injector and detector 250 ◦ C. Biological Evaluation Animals: Adult male albino rats Sprague Dawely strain weighing between (90 – 100 gm ) , were obtained from the animal house of Egyptian Organization for biological Products and Vaccines (VACSERA) Cairo, Egypt. The animals were kept in wire cages with wire bottom. The diet was introduced to the rats in special feed cup that kept food spilling to a minimum , water was provided to the rats by means of glass tube projecting through wire cage, an inverted bottle supported one side of the cage. The basal diet was formulated according to AIN 93M, according to Reeves et al., (1993). The used vitamin mixture component was that recommended by Campbell (1963) while the salt mixture used was formulated according to Hegsted (1941). Experimental Design: Twenty five rats were divided into five groups : group (A) control fed on basal diet, groups (B , C , D and E ) were allowed to feed 15% Tamiya boiled oil through the feeding period. One of each experiment continued feeding 15% Tamiya boiled oil without any supplementation saved as TBO group (B) and the other three groups of each experiment were allowed to feed 15% Tamiya boiled oil with olive oil (5%) as group (C) , sunflower oil (5%) as group (D) and flaxseed oil (5%) as group (E). Blood sampling and analysis Blood samples were collected after six weeks in tubes contain heparin as an anticoagulant from the eye plexuses under diethyl ether anesthesia and then centrifuged at 3000 rpm for 20 min. To obtain plasma, which was kept frozen until analysis. The total cholesterol was analyzed calorimetrically according to Allain et al (1974) method. HDL cholesterol was determined according to Lopez et al. (1977) method . LDLcholesterol was calculated according to formula of Kikuchi et al., (1998). The triglycerides were analyzed according to Fossati and Prencipe (1982) method. Urea and creatinine were determined according to Young (2001 ). Statistical analysis The results of the animal experiments were expressed as the Mean ± SE and they were analyzed statistically using the one-way analysis of variance ANOVA followed by Duncan’s test. In all cases p ≤ 0.05 was used as the criterion of statistical significance. RESULTS AND DISCUSSION Physical and chemical characteristics of olive oil , sunflower oil and flaxseed oil: M. A. Habieb, et al., 22 Table (1) showed the physicochemical properties of edible oils. Acid values were 1.53 mg KOH/g for olive oil , 0.42 mg KOH/g for sunflower oil and 0.85 mg KOH/g for flaxseed oil. The acid value was lower than the Codex standard value for virgin vegetable oils (4.0 mg KOH/g Oil). The