با همکاری انجمن علوم و صنایع غذایی ایران

نوع مقاله : مقاله پژوهشی

نویسندگان

1 گروه علوم و صنایع غذایی، دانشکده کشاورزی، دانشگاه شیراز، شیراز، ایران.

2 گروه پژوهشی فرآوری آبزیان، دانشکده کشاورزی، دانشگاه شیراز، شیراز، ایران.

چکیده

هدف از این مطالعه بررسی اثر روش استخراج به کمک مایکروویو بر بازدهی استخراج و بعضی از خصوصیات شیمیایی روغن جوانه گندم در مقایسه با روش متداول سوکسله بود. همچنین، روغن جوانه‌ گندم به‌عنوان یک آنتی‌اکسیدان طبیعی برای بهبود پایداری اکسایشی روغن ماهی کیلکا مورد بررسی قرار گرفت. ابتدا نمونه‌‌های جوانه گندم تحت پیش تیمار مایکروویو قرار گرفته و سپس عملیات استخراج با روش سوکسله انجام گردید. بازدهی استخراج، عدد صابونی، عدد اسیدی، عدد یدی و پروفایل اسیدهای چرب روغن جوانه‌ گندم استخراج شده با مایکروویو با روش متداول سوکسله مقایسه شدند. روغن جوانه‌ گندم در غلظت ppm 1000 به روغن ماهی کیلکا افزوده شد. روغن ماهی کیلکای فاقد آنتی‌اکسیدان نیز به‌عنوان نمونه‌ی کنترل در نظر گرفته شد. عدد پراکسید و آنیزیدین نمونه‌های روغن ماهی کیلکا طی 15 روز نگهداری در دمای 60 درجه سلسیوس اندازه‌گیری شدند. روش استخراج به کمک مایکروویو بازدهی استخراج روغن جوانه‌ گندم را 27-15% افزایش داد. ترکیب اسید چرب روغن جوانه‌ گندم استخراج شده به کمک مایکروویو مشابه با روغن استخراج شده با روش متداول سوکسله بود. عدد اسیدی و صابونی نمونه استخراج شده با مایکروویو به‌ترتیب 07/2% و 65/9% بیشتر از نمونه استخراج شده با سوکسله بود. عدد یدی در روش‌های استخراج با مایکروویو و سوکسله و به‌ترتیب برابر با 75/124 و 90/132 ‌گرم ید/100 گرم روغن بود. روغن جوانه گندم به شکل قابل توجهی عدد پراکسید، آنیزیدین و توتوکس روغن ماهی کیلکا را کاهش داد. زمان القاء و فاکتور حفاظت نمونه روغن ماهی کیلکا حاوی جوانه گندم (به‌ترتیب 20/120 ساعت و 42/1) به‌طور قابل توجهی بیشتر از نمونه‌ کنترل (به‌ترتیب 40/84 ساعت و 00/1) بود. به شکل کلی، روغن جوانه‌ گندم استخراج شده با مایکروویو می‌تواند به‌عنوان یک آنتی‌اکسیدان طبیعی جهت افزایش پایداری اکسایشی روغن ماهی کیلکا پیشنهاد شود.

کلیدواژه‌ها

عنوان مقاله [English]

Effect of wheat germ oil extracted with microwave pretreatment on the oxidative stability of common Kilka (Clupeonella cultriventris caspia) oil

نویسندگان [English]

  • Mohammad Taghi Golmakani 1
  • Marzieh Moosavi-Nasab 2
  • Malihe Keramat 1
  • Azin Azhand 1

1 Food Science and Technology Department, School of Agriculture, Shiraz University, Iran.

2 Food Science and Technology Department and Seafood Processing Research Group, School of Agriculture, Shiraz University, Iran.

چکیده [English]

Introduction: Wheat germ is a by-product of wheat milling industry. It contains about 11% oil. Wheat germ oil is well known as a tocopherol rich food lipid. It also contains more than 55% polyunsaturated fatty acids, mainly linoleic and alpha-linolenic acid (Simopoulos 1999; Schwartz et al. 2008). Wheat germ processing presents challenges due to its high content of bioactive compounds. Microwave-assisted extraction is a new extraction technology used for the extraction of bioactive compounds, which is based on combination of microwave and conventional solvent extraction. This technique which is used has many advantages such as short time, less solvent usage, and higher extraction yield (Hao et al. 2002).Common Kilka (Clupeonellacultriventris caspia) oil is considered as one of the most healthy and functional oils. It is highly rich in polyunsaturated ω-3 fatty acids such as eicosapentaenoic acid and docosahexaenoic acid. However, Kilka oil is highly vulnerable to oxidation due to its high content of poly unsaturated fatty acids. Oxidations of poly unsaturated fatty acids such as eicosapentaenoic acid and docosahexaenoic acid result in a number of oxidation products that have negative impacts on the flavor and odor of Kilka oil, and also can affect the amount of these fatty acids that are made available to the body (Lin and Lin 2004; Fazli et al. 2009; Pazhouhanmehr et al. 2015; Yu et al. 2002). In order to preserve polyunsaturated fatty acids of Kilka oil from oxidative degradation, the use of novel and effective antioxidants can offer methods to maintain the health of consumers.The objective of this study was to investigate the effect of microwave-assisted extraction method on extraction yield and some chemical characteristics of wheat germ oil in comparison with conventional Soxhlet method. Also, wheat germ oil was investigated as a natural antioxidant for improving oxidative stability of Kilka oil.

Materials and methods: Wheat germ used in this research was supplied from Sepidan Flour Mill (Shiraz, Iran). Crude Kilka oil with no added antioxidants was supplied by a local fishery factory (Rasht, Iran).Wheat germ samples were pretreated with microwave at 200 W for 5 min. Thereafter, the samples were extracted with Soxhlet method. Samples were analyzed at 2, 4, 6, 8, and 10 h of extraction process. Extraction yield, saponification value, acid value, iodine value, and fatty acid profile of wheat germ oil extracted with microwave-assisted method were compared with those extracted with conventional Soxhlet method. Fatty acid composition of wheat germ oil was determined according to the method described by Golmakani et al. (2012) with some modifications. Saponification, acid, and iodine values of wheat germ oil were determined by using the AOAC official methods (AOAC 2000). Wheat germ oil was added to Kilka oil at a concentration of 1000 ppm. For the control, Kilka oil without any added antioxidant was used. Peroxide, anisidine, and Totox values of wheat germ oil were measured during 15 days storage at 60 °C. Peroxide, anisidine, and Totox values of wheat germ oil were determined using the AOCS official methods (AOCS 2000). Induction period was considered as the number of days required for a sample to reach a PV of 20 meq O2/kg (Keramat et al. 2016).

Results and discussion: The microwave-assisted extraction method increased the extraction yield of wheat germ oil by 15-27%. Increase in extraction yield is due to cell membrane rupture by microwave which results in greater porosity, enabling the passage of oil from the cell membrane (Uquiche et al. 2008). The amounts of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids in samples extracted by microwave-assisted extraction method were similar to those extracted by conventional Soxhlet method. Acid value of samples extracted by microwave-assisted extraction method was slightly higher than those extracted by conventional Soxhlet method. This result is in agreement with the previous studies (Kiralan et al. 2014; Uquiche et al. 2008). The saponification value of wheat germ oil sample extracted by microwave-assisted extraction method was 9.65% higher than those extracted by conventional Soxhlet method. Thus, wheat germ oil sample extracted by microwave-assisted extraction method contained higher short chain fatty acids than those extracted by conventional Soxhlet method. The iodine value of wheat germ oil sample extracted by microwave-assisted extraction method was lower than those extracted by conventional Soxhlet method. Accordingly, microwave-assisted extraction method has a positive effect on the oxidative stability of wheat germ oil. Wheat germ oil significantly decreased the peroxide, anisidine, and Totox values of Kilka oil by 61.59%, 65.01%, and 61.97%, respectively, compared to the control. The induction period and protection factor of Kilka oil sample containing wheat germ oil (120.20 h and 1.42, respectively) was significantly higher than those of control sample (84.40 h and 1.00, respectively). The inhibitory effect of wheat germ oil against Kilka oil oxidation can be attributed to the presence of high amounts of biological active compounds. Based on the results of this study, microwave extracted wheat germ oil can be proposed as a natural antioxidant for improving oxidative stability of Kilka oil.

کلیدواژه‌ها [English]

  • Extraction
  • Kilka oil
  • Microwave
  • Oxidative Stability
  • Wheat germ oil
AACC. 2011. Approved Methods of the American Association of Cereal Chemists. The Association St, Paul, MN.
Amarni, F., & Kadi, H. 2010. Kinetics study of microwave-assisted solvent extraction of oil from olive cake using hexane: comparison with the conventional extraction. Innovative Food Science & Emerging Technologies: 11, 322-327.
Anjum, F., Anwar, F., Jamil, A., & Iqbal, M. 2006. Microwave roasting effects on the physico-chemical composition and oxidative stability of sunflower seed oil. Journal of the American Oil Chemists' Society, 83: 777-784.
AOAC. 2000. Official Methods of Analysis of the Association of Official Analytical Chemists. AOAC International, Arlington, VA.
AOCS. 2000. Official Methods and Recommended Practices of the American Oil Chemists’ Society. AOCS Press, Champaign, Illinois.
Asnaashari, M., Farhoosh, R., & Sharif, A. 2014. Antioxidant activity of gallic acid and methyl gallate in triacylglycerols of Kilka fish oil and its oil-in-water emulsion. Food Chemistry, 159: 439-444.
Dunford, N. T., & Zhang, M. 2003. Pressurized solvent extraction of wheat germ oil. Food Research International, 36: 905-909.
Fazel, M., Sahari, M. A., & Barzegar, M. 2008. Determination of main tea seed oil antioxidants and their effects on common Kilka oil. International Food Research Journal, 15: 209-217.
Fazli, H., Zhang, C.I., Hay., D.E., and Lee, C.W. 2009. Stock assessment and management implications of anchovy kilka (Clupeonella engrauliformis) in Iranian waters of the Caspian Sea. Fisheries Research, 100: 103-108.
Frankel, E.N. 2012. Lipid oxidation. Woodhead Publishing Limited, Cambridge, UK.
Golmakani, M. T., Mendiola, J. A., Rezaei, K., & Ibañez, E. 2012. Expanded ethanol with CO2 and pressurized ethyl lactate to obtain fractions enriched in γ-Linolenic Acid from Arthrospira platensis (Spirulina). Journal of Supercritical Fluids, 62: 109-115.
Hao, J. Y., Han, W., Xue, B. Y., & Deng, X. 2002. Microwave-assisted extraction of artemisinin from Artemisia annua L. Separation and Purification Technology, 28: 191-196.
Hashemi, M. B., Niakousari, M., Saharkhiz, M. J., & Eskandari, M. H. 2011. Influence of Zataria multiflora Boiss essential oil on oxidative stability of sunflower oil. European Journal of Lipid Science and Technology, 113: 1520-1526.
Hashemi, M.B., Niakousari, M., Saharkhiz, M.J., & Eskandari, M.H. 2012. Effect of Satureja khuzestanica essential oil on oxidative stability of sunflower oil during accelerated storage. Natural product research, 26: 1458-1463.
Hraš, A.R., Hadolin, M., Knez, Ž., & Bauman, D. 2000. Comparison of antioxidative and synergistic effects of rosemary extract with α-tocopherol, ascorbyl palmitate and citric acid in sunflower oil. Food Chemistry, 71: 229-233.
Kahlon, T. 1989. Nutritional implications and uses of wheat and oat kernel oil. Cereal Foods World, 34: 135-142.
Keramat, M., Golmakani, M.T., Aminlari, M., & Shekarforoush, S.S. 2016. Comparative effect of Bunium persicum and Rosmarinus officinalis essential oils and their synergy with citric acid on the oxidation of virgin olive oil. International Journal of Food Properties, 19: 2666-2681.
Kiralan, M., Özkan, G., Bayrak, A., & Ramadan, M. F. (2014). Physicochemical properties and stability of black cumin (Nigella sativa) seed oil as affected by different extraction methods. Industrial Crops and Products, 57: 52-58.
Knothe, G. 2002. Structure indices in FA chemistry. How relevant is the iodine value?. Journal of the American Oil Chemists' Society, 79: 847-854.
Ko, T. F., Weng, Y. M., & Chiou, R. Y. Y. 2002. Squalene content and antioxidant activity of Terminalia catappa leaves and seeds. Journal of Agricultural and Food Chemistry, 50: 5343-5348.
Kou, D., & Mitra, S. 2003. Extraction of semi volatile organic compounds from solid matrices. Sample Preparation Techniques in Analytical Chemistry, 7: 139-182.
Lin, C. C., & Lin, C. S. 2004. Enhancement of the storage quality of frozen bonito fillet by glazing whit tea extracts. Journal of Food Chemistry, 16: 169-175.
Małecka, M. 2002. Antioxidant properties of the unsaponifiable matter isolated from tomato seeds, oat grains and wheat germ oil. Food Chemistry, 79: 327-330.
Malekian, F., Rao, R. M., Prinyawiwatkul, W., Marshall, W. E., Windhauser, M., & Ahmedna, M. 2000. Lipase and lipoxygenase activity, functionality, and nutrient losses in rice bran during storage. Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center.
Motalebi, A. A., & Seyfzade, M. 2011. Effects of whey protein edible coating on bacterial, chemical and sensory characteristics of frozen common kilka (Clupenelliadelitula). Iranian journal of Fisheries Sciences, 11: 132-144.
Owen, R. W., Mier, W., Giacosa, A., Hull, W. E., Spiegelhalder, B., & Bartsch, H. 2000. Phenolic compounds and squalene in olive oils: the concentration and antioxidant potential of total phenols, simple phenols, secoiridoids, lignansand squalene. Food and Chemical Toxicology, 38: 647-659.
Pazhouhanmehr, S., Farhoosh, R., Esmaeilzadeh Kenari, R., & Sharif, A. 2015. Oxidative stability of purified common Kilka (Clupeonella cultiventris caspia) oil as a function of the bene kernel and hull oils. International Journal of Food Science & Technology, 50: 396-403.
Panfili, G., Cinquanta, L., Fratianni, A., & Cubadda, R. 2003. Extraction of wheat germ oil by supercritical CO2: oil and defatted cake characterization. Journal of the American Oil Chemists' Society, 80: 157-161.
Pirestani, S., Sahari, M., Barzegar, M., Nikoopour, H. 2010. Lipid, cholesterol and fatty acid profile of some commercially important fish species from south Caspian Sea. Journal of Food Biochemistry, 34: 886-895.
Schwartz, H., Ollilainen, V., Piironen, V., & Lampi, A. M. 2008. Tocopherol, tocotrienol and plant sterol contents of vegetable oils and industrial fats. Journal of Food Composition and Analysis, 21: 152-161.
Simopoulos, A. P. 1999. Essential fatty acids in health and chronic disease. The American Journal of Clinical Nutrition, 70: 560-569.
Uquiche, E., Jerez, M., & Ortiz, J. 2008. Effect of pretreatment with microwaves on mechanical extraction yield and quality of vegetable oil from Chilean hazelnuts (Gevuina avellana Mol). Innovative Food Science and Emerging Technologies, 9: 495–500.
Yu, L., Scanlin, L., Wilson, J., and Schmidt, G. 2002. Rosemary extracts as inhibitors of lipid oxidation and color change in cooked turkey products during refrigerated storage. Journal of Food Science, 67: 582-585.
CAPTCHA Image