Journal of food science and technology
Year:2013 | Volume:9 | Issue:39|Papers Count:14

In this study three different varieties of olives from Fars Province were chosen and subjected to oil extraction. The varieties are Zard (Iran), Arbeqina (Spain) and Kronaiky (Greek). We harvest their fruit in 4 mounts: Mordad, Shahrivar, Mehr and Aban. In this study changes in the polyphenol composition of the oil extracted from olive fruit by HPLC and oil percent by Soxhlet during the course of maturation is investigated. This work is concerned with the best harvesting point when total polyphenol reaches its maximum concentration. The quantitative and qualitative determinations concerned with the polyphenol composition were carried out on the oil and concluded the maturation of olives depending on the variety played an important role in the polyphenol composition and oil percent of the extracted oils.

Several epidemiological studies have shown that diets rich in olive oil, which is the major source of Mono Unsaturated Fatty Acids (MUFA) and Phenol compounds, have a great role in reducing cholesterol levels and preventing platelet aggregation. It is also seems that such diets have inverse relation with risk factors of chronic disease such as obesity and metabolic syndrome. This cross sectional study was conducted to assess the consumption of olive oil and its relation to metabolic syndrome in obese children of elementary first grade in Tehran in the frame of "Assessing the effect of lifestyle modification intervention in elementary school obese children ". Subjects were 156 obese children (BMI≤95thin compare with CDC2000) who were referred to health assessment centers in districts 1, 2 and 3 of Tehran. For each subject, demographic and food frequency questionnaires were fulfilled and anthropometric (weight, height) and biochemical (Fasting blood sugar, Triglycerides, Total cholesterol, HDL cholesterol) indices and their blood pressure were measured by experts using standard protocols. Metabolic syndrome was defined on the basis of modified ATPIII criteria for children and adolescents as meeting at least three indicators (abdominal obesity, hypertension, low HDL-c, elevated serum Tg, high FBS) in addition to obesity. Data were analyzed using Spss ver16. Among children, 52% were girls. Mean and standard deviation of age, weight, height and BMI were 80.07 ± 3.8 Mo, 37.5 ± 6.3 Kg, 127.19 ± 4.75 Cm and 23.08 ± 2.9Kg/m2, respectively. Prevalence of metabolic syndrome was %13.4, in girls and boys were %10.3 and %16.7, respectively and this difference was statistically significant (P<0.05). Mean of daily consumption of olive oil was less in metabolic syndrome group (3.67 ± 1 V.s.6.34 ± 1.3) and in contrast, they consumed more saturated fat (8.24± 3V.s.5.7 ± 1.7) which the difference was nearly significant. According to increasing prevalence of obesity and metabolic syndrome and its relation to fat consumption pattern, further considerations should be pay to amounts and kind of dietary fat, especially olive oil to prevent metabolic syndrome.

In the present study, sampling was carried out using 7 extra virgin olive oils from Gillan, Zanjan, Ghazvin, Golestan, Fars and Kermanshah Province. The amounts of the chlorophylls and carotenoidswere determined for each sample using diol-phase cartridges and the extract was analysed by reverse-phase HPLC. Pheophytina (29/29%) show the highest content of all pigments in Iranian extra virgin olive oils and pyropheophytin (0/14%) show the lowest concentrations. Lutein (51/48%) show the highest content of all carotenoids pigments followed by violaxanthin in Iranian olive oils and betacaroten (0/76%) and anthraanthin show the lowest concentrations. Pheophyting a shows the highest content of all pigments followed by chlorophyll a in Iranian olive oils and pheophytina andpyropheophytin show the lowest concentrations.The correlation between amount of pigments and three environment factors; temperature, raining fall and height were investigated. Statistical studies showedthere is a direct relationship between pyropheophytin content and the hight of sampeling local with a 95% confidence limit.An increase in hight resulted in decrease pigments.And also there is a positive correlation at 95% confidence level between lutein and raining of sampeling local.When raing of sampling local increases, lutein has been increasing as well. Statistical studies showed no correlation between temperature and amount of pigmens in the olive oils.

Olive’s fruit are recommended to eat for the reason of containing mono unsaturated (MUFA, such as oleic acid), omega 3 and omega 6 fatty acids and bioactive compounds. The processing of table olive is included crud, lye treatment, washing, fermentation and pasteurization steps which makes it as an edible fruit. In this processing the most important physico-chemical, nutritional, organoleptical (flavor and color) changes are done. So in this study, the quantities of changing in nutritional indexes in five olive cultivars during 5 mentioned steps of processing from harvesting are examined. Olive cultivars (Zard, Fishomi, Ascolana, Amiglalolia and Conservalia) were collected from Fadak Farm in Iran (Qom Province) and the amounts of oil, sum of saturated fatty acids (SFA), MUFA, poly unsaturated fatty acids (PUFA), PUFA/SFA and omega 3/omega 6 were studied. The limitation of oil in studied cultivars was 14-19.5% and the highest and lowest one was in Ascolana and Fishomi in crud and pasteurization steps, respectively. The sum content of SFA and UFA were 19.5-26.5% and 73.5-80.5%, respectively, and the most of these fatty acids were in fermentation step. The ratio of omega 3 to omega 6 in studied cultivars was 0.2-0.5 and the highest and lowest ratio was in Ascolana and Zard in washing and pasteurization steps, respectively. Processing of table olive has made a lot of changes in some valuable compounds of olives fruit. The result showed that the highest amount of oil were in Ascolana and Amigdalolia cultivars, so suggested that, these two cultivars for oily using and the other ones are less important for this reason. Also, Zard, Fishomi and Conservalia cultivars not had any significant differences in oil content. Therefore, according to spoil of oil during of processing, the amount of oil was higher in Ascolana and Amigdalolia in pasteurization step. This result was emphacised that the latest two cultivars were suitable for oily using. For processing table olive purpose the Ascolana and Amigdalolia cultivars are recommended. The percentage of oil was increased in Zard and Conservalia cultivars during processing and these changes were depended on the condition of processing steps and the kind of cultivar. Using of olives fruit is very important for their unique oil, its fatty acids, high biological properties and nutritional values. According to this reason, selecting some cultivars that has less spoil in processing is recommended.

In this research we scrutinize the temperature effect on  DECN42 and the olive oil produced in Shiraz during 1388 crop year in Iran. Samplings were divided into two groups of natural and refined olive oil. The analysis of fatty acids was done by GC apparatus and with uses this result theoretical ECN42 by software was analyzed. The essential ECN42 was analyzed by HPLC apparatus as well. Statistical analysis showed a positive relation between 2 parameters of ECN42 and linoleic acid (0.05). And statistical test of theoretical and essential ECN42 showed a significant relation in 0.01 levels.

In the present study, sampling was carried out using 7 virgin olive oils from different Province. The amounts of the carotenoids were determined for each sample using diol-phase cartridges and the extract was analysed by reverse-phase HPLC. For evaluating the stability of olive oil samples, the peroxide value measured 4 continus weeks in two different coditions of light and darkness. Given to the obtained results lutein (51.48%) show the highest content of all carotenoids pigments in Iranian olive oils and betacaroten (0.76%) show the lowest concentrations. Cis lutein pigment is one of the pigment affecting olive oil stability in the light acting as a pro-oxidant to reduce the stability and increase peroxide index. Betacryptoxanthin is factor that affecting the stability of oil exposed to darkness acting as peroxidants to reduce the stability and increase rancidity.

Oil in foodstuff deep frying heated to a long time and effect of some factors (humidity, temperature and oxygen) cause different chemical and physical changes of the oil (such as hydrolysis, oxidation and polymerization) and degrade the quality of the oil and product. The results of these changes increase of the free fatty acids, peroxide value, polar compounds and trans isomers, and also decrease of the unsaturated fatty acids, oxidation induction time, levels of tochopherol and phenolic compounds, which all indicate a decline the oil quality. Studies shows that the chemical composition of oil and especially natural antioxidants are important parameters in predictive the behavior of oil in the frying process. Independently to the commercial category of olive oil, is clearly resistant against the deep frying. In this paper, the oxidative stability of oil during frying according to the source, the presence of natural bioactive compounds (antioxidants) and fatty acid composition have been compared with olive oil.

Standards as the most important scientific documents adopted by international trade is based on the safety and health for food standards which are divided to international (such as ISO and IOOC), regional (such as EC), national (such as ISIRI), company and factory levels. In this regard, the importance of olive oil as the vegetable oil is extracted from the olive fruit and posse’s important specification like organoleptic properties, nutritional composition and oxidative stability; standards have the main role in the quality and purity criteria. In the latest scientifically valid methods are used to detection of adulteration and determination of purity of olive oil. In this paper, is specified the parameters standards of quality and purity that derived from national standard, EC regulation, Codex alimentarius food standards and International olive oil council.

Application of synthetic antioxidants is restricted due to possible toxic and carcinogenic products resulting from their decomposition. Thus, studies on natural antioxidant as an alternative to synthetic antioxidants would be of great importance. In this study, rosemary, oregano and mint powders were added to virgin olive oil at level of 2.5% (w/w) and then stored for 7 days at 750C in two forms of sealed and unsealed for further analysis. Free fatty acid content, peroxide value, cis-trans isomers and oxidative stability of samples based on peroxide value changes were measured. Results showed that an increase occurred in oxidative stability of virgin olive oil samples containing rosemary and mint powders. There was also no significant difference (p>0.01) between control and spice treated samples in cis-trans fatty acids, SFA, MUFA, PUFA, TTFA, oxidative stability and MUFA/PUFA ratio.