Determination Of Fatty Acids In Some Grape Cultivars By Gas Chromatography Mass Spectrometry

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1 International Research Journal of Applied and Basic Sciences 203 Available online at ISSN X / Vol, 4 (6): Science Explorer Publications Determination Of Fatty Acids In Some Grape Cultivars By Gas Chromatography Mass Spectrometry MARYAM GHOREISHI *, FATIMAH RAHMANI 2, HAMED DOULATI BANEH 3. Department of Biology, Islamic Azad University, Marand, Iran 2. Institute of Biotechnology, Urmia University, Urmia, Iran 3. Agriculture Research Center, Urmia, Iran *Corresponding Author ghoreishymaryam@yahoo.com ABSTRACT: In the present study, seeds of five grape varieties, grown in the West Azarbaijan (Iran), were examined for determination of fatty acids composition. The results revealed that grape seeds were rich in linoleic acids, palmitic acid and stearic acid ranging from to 8.56%, 7.9 to.49% and 3.6 to 5.8%, respectively. The highest linoleic acid content was found in Shirazi grape, while Rezghi showed the highest palmitic acid content. Goye maleki showed higher stearic acid content than other cultivars studied. The linoleic and palmitic acids were the most useful parameters to discriminate the five grape varieties. The highest oleic acid content was found in Rasha which discriminated this variety from other cultivars. In conclusion, these grape seeds could be used as a food supplement to improve the nutritive value of the human diet. They can also be utilized as a source of fatty acids to obtain edible vegetable oil. Keywords: Fatty acid, FAMEs, GCMS; Oleic acid; Linoleic acid; Palmitic acid; Stearic acid. INTRODUCTION Grapes belong to the family Vitaceae and the genus Vitis has been grouped in two sections, series, and more than 60 species (Galet, 998). Vitis vinifera L., the most widely cultivated species of Vitis genus by far, is grown throughout the temperate and tropical regions of the world for fresh fruit, raisin, juice, and wine (Riaz et al., 2004: Winkler et al., 974). Grapes are one of the fruit crops grown widely in many areas of the world and 46% of the fresh grapes are accounted for in wine production (Anonnemous, 989). The traditional methods for extracting grape seed oil consist of pressing the whole seeds in discontinuoushydraulic press or the milled and heated seeds in screw press, but both have low costeffectiveness (Laufenberg et al., 2003). At the present, they have been replaced almost totally by solvent (hexane, generally) extraction after crushing seeds in roller mills and heating. Then, the crude oil is neutralized, bleached with activated carbon and clay which finally deodorized under vacuum. Yield of this extraction method is high but several hours are necessary to complete the extraction step. Solvent extraction using hexane is the most widely used procedure on an industrial scale, although extraction with supercritical CO2 has been proposed (Beveridge et al., 2005: Molero., 996). Extraction by physical means using a hydraulic or a screw press is also possible (Rohne., 97). Very little information is available on the properties of the grape seed oil obtained by different methods. The main objective of this study is to characterize fatty acid composition of different grape varieties using gas chromatography mass spectrometry (GCMS) and explain the chemotaxonomic significance of them. MATERIALS AND METHODS The selected varieties include Ghara gandoma, Goye maleki, Rezghi, Shirazi and Rasha (Figure2) which currently were collected from the germplasm collection of Agriculture Research center in Azerbaijan (Iran) (Table). The grapes were crushed in the winery, after removing the stems. The seeds were immediately separated from the crushed grapes and immediately afterwards put to dry. Seeds from grape residues were dried for 24 h at 60 C in the oven. An optimization study of influential variables on superheated hexane extraction (namely extraction time, temperature, pressure, particle size and sample amount) was carried out by a multivariate approach. All extracts were concentrated in oven and dried. To obtain fatty acid methyl esters (FAMEs), 2 ml of the dried extracts were subjected for reaction with 0.5 M solution of KOH in methanol and

2 Intl. Res. J. Appl. Basic. Sci. Vol., 4 (6), 46747, 203 hexane. The analysis of the essential oil was performed using a Thermo FinniganTraceM2000 GC MS, equipped with a HP5 MS capillary column. Helium was the carrier gas, at a flow rate of 35 ml/min. Injector and detector temperatures were 200 and 250 C, respectively. Column temperature was initially kept at 20 C for 5 min, and then gradually increased to 260 C at a 0 C /min rate. The components were identified based on the comparison of their relative retention time and retention indices with Wily library data of the GC MS system and literature data (Fig) (Adams., 995). MS parameters were as follows: ionization energy, 70eV; ion source temperature, 200 C; voltage, 3000 v; and mass range, 30 to 600. The compositions of the essential oil were identified by comparison of their retention indexes (RI), retention times (RT) and mass spectra with those of authentic samples in Wiley library (Izzo et al., 2000). RESULTS AND DISCUSSION The oil contents and some oil quality properties of grape seeds obtained from 5 grape cultivars are given in Table 2. The grape cultivars used in the present study differed in their oil content. The results revealed that grape seeds were rich in linoleic, palmitic and stearic acids (Table 2).The highest linoleic acid content was found in Shirazi grape, while Rezghi showed the highest palmitic acid content. Goye maleki showed higher stearic acid content than other cultivars studied. The highest oleic acid content was found in Rasha sardasht which discriminated this variety from other cultivars. The linoleic and palmitic acids were the most useful parameters to distinct the five grape varieties. Seeds from grape residues were dried for 24 h at 60C in the oven. Compared with other vegetable oils, grape seed oil is high in linoleic acid, equaled to safflower seed oil (Association of Official Agricultural Chemists. 990: Pardo et al., 2009). In fact, the linoleic acid was the predominant fatty acid in grape seed oils followed by palmitic, stearic, myristic, arashidonic and oleic acids. Fatty acid concentrations of the cultivars had the following range: 8.5 to.5% for palmitic, 3.5 to 6% for stearic, 0. to 3.5% for oleic, 72.4 to 8.56% for linoleic. Other fatty acids present in small quantities were oleic (0.00 to 3.5%), arachidic (0.00 to 0.94), palmitoleic (0.00 to 0.67) and Myristic acid (0.00 to 0.3%) (Table 2). The oleic acid was not determined in the oil of Rezghi and Shirazi cultivars and Shirazi completely lacked myristic acid and arachidic acid. As reported previously (Schuster., 992), grape seed oil contained mainly palmitic, stearic, oleic, and linoleic acids. Ohnishi et al. (990) reported that the range of fatty acids in the seeds of five grape cultivars were 6.7 to 8.9% for palmitic,. to 5.3% for stearic, 9.7 to 7.5% for oleic, 69.2 to 80.5% for linoleic and less than 0.% for palmitoleic and linolenic acids. These results showed that the ratios of the fatty acids have less variability. The fatty acid composition of the grape seed oil is placed among the oils of safflower, sunflower, soybean, maize, cotton seed, poppy and tobacco, which are linoleic type (Weiss, 983). As reported previously (Ohnishi et al., 990), the fatty acid composition of grape seed oil was similar to that of sunflower oil. Sunflower oil generally comprises 60% linoleic, 25% oleic, 8% palmitic and 5% stearic acid (Weiss., 983). The simple correlation coefficients among fatty acids of the grape seeds are given in Table 3. The lowest negative similarity correlation was observed between Linoleic acid and Myristic acid with a relatively low numerical value of 0.77 while, the highest positive similarity correlation was found between Arachidic acid ' and Palmitoleic acid (0.89). The most remarkable correlation among the fatty acids was found between oleic and linoleic acid, which are primary fatty acids in grape seed oil. Our results concur with those obtained by other researchers, even though they used a different oil extraction system (Izzo et al., 2000: Molero., 996 and Zeany et al., 982). The discontinuous superheated hexane extraction of grape seed fatty acids has been studied. This technique has one substantial advantage over the conventional industrial extraction method: the very much shorter extraction time, which involves a drastic cost reduction. In conclusion, there is a variation among cultivars in fatty acid composition. Moreover, grape seeds can be utilized as a source of fatty acids to obtain edible vegetable oil. ACKNOWLEDGMENTS The Authors give special thanks to authorities of Biotechnology Institute of Urmia University.

3 Intl. Res. J. Appl. Basic. Sci. Vol., 4 (6), 46747, 203 No Table. List of the grape (Vitis vinifera L.) cultivars studied. Cultivar Origin Genetic composition Ghara Urmia gandoma Goye maleki Urmia Rasha Kurdestan Rezghi Urmia Shirazi Shiraz Linoleic acid Palmitic acid Stearic acid Oleic acid Myristic acid Arachidic acid Palmitoleic acid Flurene Diphenil amine Phenol Phthalic acid Linolein Linolenin Table 2. Fatty acid composition of the grapes seed oil samples. Components (%) Ghara Ghandoma Goye maleki Rasha Rezghi Shirazi Figure. Rasha typical chromatogram of some Fatty acids obtained from GC MS analysis

4 Intl. Res. J. Appl. Basic. Sci. Vol., 4 (6), 46747, 203 Table 3. Correlation coefficient between fatty acids. F F2 F3 F4 F5 F6 F7 F8 F9 F0 F F2 F3 F F F F F F F * F ** 9 F F F ** 0.25 F ** **.000** F ** **.000** * Significant at 0.05, ** Significant at 0.0 level F: Linoleic acid, F2: Palmitic acid, F3: Stearic acid, F4: Oleic acid, F5: Myristic acid, F6: Arachidic acid F7: Palmitoleic acid, F8: Flurene, F9: Diphenil amine, F0: Phenol,F: Phthalic acid, F2: Linolein, F3: Linolenin. a) Goye maleki b) Rasha c) Shirazi Figure2. Three cultivars of Vitis vinifera used in this study. Figure3. Comparison of major fatty acid components among 5 Grape cultivars.

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