فهرست مطالب z. piravi vanak

Concentrations and profiles of 15 Environmental Protection Agency (EPA) priority Polycyclic Aromatic Hydrocarbons (PAH) of six different edible oils consumed in Iran markets (oils of olive, sesame, coconut, sunflower, frying and blend oil) were studied. The evaluated edible oils in the present study have not previously been analyzed concerning their contents of PAH compounds. PAHs of 207 edible oil samples were determined and quantified by High-Performance Liquid Chromatography with Spectrofluorometric Detector (HPLC/FLD). The results revealed that the highest content of total PAHs was in coconut oil group (46.8 µg kg-1), followed by blend oil (22.48 µg kg-1), frying oil (20.67 µg kg-1), sesame oil (19.92 µg kg-1), olive oil (18.4 µg kg-1) and sunflower oil (17.6 µg kg-1). The light PAHs (Naphthalene, Acenaphtene, Phenantherern, Antrathene, and Fluorene) had the highest portion of PAHs concentration. Benzo[a]pyrene and PAH4 contents (Benz[a]anthracene+Chrysene+Benzo[b]fluoranthene+Benzo[a]pyrene) were ND-1.32 µg kg-1 and 0.14-9.2 µg kg-1, respectively; coconut oil had the highest content. In general, the highest values of Benzo[a]pyrene and PAH4 were not higher than the maximum allowable values of 2 and 10 in any sample, respectively. However, due to the significant content of total PAHs in some vegetable oils, such as coconut oil, it is necessary to determine the limits and evaluate it in the national standard and regulations of the country.

Considering the importance of bleaching earth with activated carbon in reduction of impurities in vegetable oils, this study was conducted to investigate the effects of bleaching process on physicochemical properties of the bleached soybean oil. The bleaching process was carried out with bleaching earth (1 % w/w) containing different concentrations of activated carbon (0.1 % up to 0.5 % w/w). The results indicated that bleaching process did not affect the structure of the oil while the percentage of free fatty acids (FFA) of the oil samples after bleaching was increased as compared to the blank. During bleaching, peroxide values of the samples and color were decreased. Since the vegetable oils have been shown to be the major sources in the diet therefore the refining particularly the bleaching process plays a decisive role in the production of high quality oil. Therefore this step is one of the critical control points (CCP) in ensuring the quality of the final product.

The issue of the integrity of edible oils and fats can be considered in three main areas of safety, authenticity and quality in accordance with the standardization approach. Safety is the most essential part of the food, including edible oils, due to effects on health of consumers. Authenticity equivalent to purity is also an important aspect of this approach. The nature and prevention of fraud in the trade are examples of this part. The role of quality part in respect of nutritional value, durability during storage and apparent characteristics in terms of acceptance and satisfaction of consumers is indisputable.

In this study, an analytical method is developed to determine 15 polycyclic aromatic hydrocarbons (PAHs) in olive and refined pomace olive oils using HPLC coupled with a fluorescence detector. The standardised method of ultrasound-assisted solvent extraction consisted of liquid–liquid extraction with organic solvent and purification on C18 and Florisil bonded-phase cartridges was modified for the refined olive and refined pomace olive oils. The modification included the clean-up by solid phase extraction on an amino cartridge eluting with toluene. The limits of detection and limits of quantitation were 0.19-0.97 µg kg-1 and 0.57-2.93 µg kg-1, respectively. The PAHs recoveries ranged from 75% to 110% (RSD = 3–8%).The performance of the present method was evaluated for determination of PAHs in various types of olive oils samples, and suitable results were obtained. The variable levels of PAHs were detected ranging from 0.61 to 6.30µgkg-1 in real samples.

Olive oil in general due to it monounsaturation, stability, nutritive value, consistency, taste andaroma might be considered as a valuable and luxury oil. Annual importation of olive oil to Iran fromMediterranean countries is on a large scale although some olive oils are produced in Iran particularly in the northand some plantation has been applied in different provinces particularly in Fars. The value of this luxury oileither imported or produced internally provides a ground for adulteration. The aim of this work is to evaluate thechemical characteristics of three varieties (Mari, Arbequina, Koroneiki) of olive oils from two regions (Fadakand Gilvan).Three varieties of olive fruit in two regions were selected and the extracted oils were subjected to aseries of chemical tests consisting of acid value, peroxide value, Iodine value, fatty acid profile as well asphenolic content and sterol composition. The results indicated that all of the samples in terms of acid andperoxide values were consistent with the values defined for extra virgin olive oil. The fatty acid compositionindicated that oleic acid was the predominant fatty acid ranging from 56 to 77% of the total fatty acids indicatingthe Italian and Spanish origins. The analysis of sterol fraction showed that <-sitosterol was the major and thepredominant sterol (88%). The phenolic concentration in this study was 100-250 mg/kg as gallic acid. The studyillustrated that the investigated samples were in agreement with the standard of CODEX and the Iranian nationalstandard in spite of differences obtained.

With regard to the significant functions of nuts in preventing cardiovascular diseases and certain kinds of cancer as well as their high consumption in our country, the present research was conducted to identify some characteristics of Iranian nut oils including walnut, almond, pistachio with cultivars Damavand, c.v.b12, Ahmad Aghaee with %4, Momtaz by measuring the total phenolic compounds using folin assay, identifying fatty acids profile by GC, oil oxidative stability at three different temperatures: / by Rancimat method and measuring other oxidative stability by Oven Test. Folin assay results showed that walnut consists the most phenolic compounds, then were pistachio and almond, respectively. Rancimat test results indicated that pistachio possessed the highest oxidative stability in each of three mentioned temperatures and then were almond and walnut, respectively. The results of the other oil oxidative stability showed the most oxidative stability among the mentioned oils and the conclusion of variation trend of peroxide index with less rate was in pistachio and then were almond and walnut, respectively. The important results of the fatty acids profile indicated that pistachio contained the most saturated fatty acids and the least saturated fatty acids belonged to walnut. Among the mentioned oils, almond oil had the least poly-unsaturated fatty acids and walnut had the most one. In addition, almond possesed higher oleic acid, then were pistachio and walnut, respectively. According to these findings and inspite of having high phenolic compounds in walnut oil compared with other mentioned oils, it is concluded that the profile of fatty acids has a more effective and crucial role in the stability of oils oxidation.