Grasas y Aceites, Vol 68, No 3 (2017)

Monitoring the physicochemical features of sunflower oil and French fries during repeated microwave frying and deep-fat frying

E. Aydınkaptan, I. Barutçu Mazı



This study investigates the effects of repeated microwave frying at different power levels (360W, 600W, 900W) and deep-fat frying on sunflower oil and French fries. The intermittent batch frying cycle was repeated 15 times a day during five consecutive days. The fatty acid profile and physicochemical properties including free fatty acid (FFA), extinction coefficient (K270), total polar compound (TPC), color, viscosity, refractive index of the sunflower oil were determined each day. At the end of the frying period, the highest values of viscosity (76.29cp) and refractive index (1.4738) were detected in microwave frying at 900W power level. TPC level exceeded 25% after the third day of microwave frying at all power levels. The FFA values during microwave frying increased progressively from 0.157% to 0.320- 0.379% on the fifth day. The loss of polyunsaturated fatty acids was 37-53% more in the case of microwave frying. The oil quality during microwave frying did not have a significant impact on the oil absorption and total color change of the French fries. Microwave frying, even at higher levels, provided lower oil (8.60-12.32%wb) and moisture contents (35.47-41.24%) compared to deep frying. Microwave frying caused longer processing time and significantly higher levels of degradation of the sunflower oil at all power levels compared to deep frying. However, microwave frying has the advantage of reducing oil absorption. The oil content of French fries was lowered by 20-33% (wb) at the highest power level.


Deep-fat frying; Fatty acids profile; French fries; Microwave frying; Physicochemical properties

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Aladedunye F. 2015. Curbing thermo-oxidative degradation of frying oils: current knowledge and challenges. Eur. J. Lipid Sci. Technol. 117, 1867-1881.

Albi T, Lanzón A, Guinda A, León M, Pérez-Camino MC. 1997a. Microwave and conventional heating effects on thermoxidative degradation of edible fats. J. Agric. Food Chem. 45, 3795–3798.

Albi T, Lanzón A, Guinda A, Pérez-Camino MC, León M. 1997b. Microwave and conventional heating effects on some physical and chemical parameters of edible fats. J. Agric. Food Chem. 45, 3000–3003.

American Oil Chemists’ Society (AOCS). 2005. Official Methods and Recommended Practices of the American Oil Chemists’ Society. American Oil Chemists’ Society Press, Champaign, IL.

Association of Official Analytical Chemists (AOAC). 1984. Official Methods of Analysis of the Association of Official Analytical Chemists, 14th ed, Washington, DC.

Association of Official Analytical Chemists (AOAC). 1990. In Helrich K (Ed). Official Methods of Analysis of the Association of Official Analytical Chemists. Association of Official Analytical Chemists, Inc., Virginia.

Barutcu I, Sahin S, Sumnu G. 2009. Acrylamide formation in different batter formulations during microwave frying. LWT-Food Sci. Technol. 42, 17-22.

Bendini A, Valli E, Cerretani L, Chiavaro E, Lercker G. 2009. Study on the effects of heating of virgin olive oil blended with mildly deodorized olive oil: Focus on the hydrolytic and oxidative state. J. Agric. Food Chem. 57, 10055-10062.

Berdeaux O, Marmesat S, Velasco J, Dobarganes MC. 2012. Apparent and quantitative loss of fatty acids and triacylglycerols at frying temperatures. Grasas Aceites 63, 284-289.

Borges TH, Malheiro R, de Souza AM, Casal S, Pereira JA. 2015. Microwave heating induces changes in the physicochemical properties of baru (Dipteryx alata Vog.) and soybean crude oils. Eur. J. Lipid Sci. Technol. 117, 503-513.

Chen SD, Chen HH, Chao YC, Lin RS. 2009. Effect of batter formula on qualities of deep-fat and microwave fried fish nuggets. J. Food Eng. 95, 359-364.

Chen WA, Chiu CWP, Cheng WC, Hsu CK, Kuo MI. 2013. Total polar compounds and acid values of repeatedly used frying oils measured by standard and rapid methods. J. Food Drug Ana. 21, 58-65.

Chirinos R, Huaman M, Betalleluz-Pallardel I, Pedreschi R, Campos D. 2011. Characterisation of phenolic compounds of Inca muna (Clinopodium bolivianum) leaves and the feasibility of their application to improve the oxidative stability of soybean oil during frying. Food Chem. 128, 711-716.

Croon LB, Rogstad A, Leth T, Kiutamo T. 1986. A comparative study of analytical methods for quality evaluation of frying fat. Fett Wiss. Technol. 88, 87–91.

Crosa MJ, Skerl V, Cadenazzi M, Olazabal L, Silva R, Suburu G, Torres M. 2014. Changes produced in oils during vacuum and traditional frying of potato chips. Food Chem. 146, 603- 607.

Datta AK. 1990. Heat and mass transfer in the microwave processing of food. Chem. Eng. Prog. 86, 47-53.

Decareau RV, Peterson RA. 1986. Microwave processing and engineering. Ellis Horwood Ltd., VCH Publishers, Deerfield Beach, FL.

Dobarganes C, Márquez- Ruíz G, Velasco J. 2000. Interactions between fat and food during deep-frying. Eur. J. Lipid Sci. Technol. 102, 521–528.

Dobarganes MC, Márquez- Ruíz G, 1998. Regulation of used frying fats and validity of quick tests for discarding the fats. Grasas Aceites 49, 331-335.

Dobarganes MC, Pérez-Camino MC. 1988. Fatty acid composition: a useful tool for the determination of alteration level in heated fats. Rev. Franç. Corps Gras 35, 67-70.

Feng H, Tang J. 1998. Microwave finish drying of diced apples in a spouted bed. J. Food Sci. 63, 679-683.

Gabriel C, Gabriel S, Grant EH, Halstead BSJ, Mingos DMP. 1998. Dielectric parameters relevant to microwave dielectric heating. Hem. Soc. Rev. 27, 213-224.

Gertz C. 2000. Chemical and physical parameters as quality indicators of used frying fats. Eur. J. Lipid Sci. Technol. 102, 566-572.

Gharachorloo M, Ghavami M, Mahdiani M, Azizinezhad R. 2010. The effects of microwave frying on physicochemical properties of frying and sunflower oils. J. Am. Oil Chem. Soc. 87, 355-360.

Ghosh J, Banerjee A, Gupta SS, Sengupta A, Ghosh M. 2014. Comparative degradation effects of sesame and soybean oil during heating using microwave irradiation. J. Sci. Ind. Res. 73, 547-552.

Hassanein MM, El-Shami SM, El-Mallah MH. 2003. Changes occurring in vegetable oils composition due to microwave heating. Grasas Aceites 54, 343-349.

Kaya Y, Kaya V, ?ahin I, Ustun Kaya M, Evci G, Citak N. 2008. The future potential of oleic type sunflower oil in Turkey. Proc. 17th International Sunflower Conference, Córdoba, Spain, 791-795.

Knutson KM, Marth EH, Wagner MK. 1987. Microwave heating of food. LWT-Food Sci. Technol. 20, 101-110.

Laguerre M, Lecomte J, Villeneuve P. 2007. Evaluation of the ability of antioxidants to counteract lipid oxidation: Existing methods, new trends and challenges. Progress Lipid Res. 46, 244-282.

Loewe R. 1993. Role of ingredients in batter systems. Cereal Foods World 38, 673-677.

Marmesat S, Rodrigues E, Velasco J, Dobarganes C. 2007. Quality of used frying fats and oils: comparison of rapid tests based on chemical and physical oil properties. Int. J. Food Sci. Technol. 42, 601-608.

McGill EA. 1980. The chemistry of frying. Bakers Dig. 54, 38-42.

Miranda ML, Aguilera JM. 2006. Structure and texture properties of fried potato products. Food Rev. Int. 22, 173-201.

Mishra R, Sharma HK. 2014. Effect of frying conditions on the physico-chemical properties of rice bran oil and its blended oil. J. Food Sci. Technol. 51, 1076-1084.

Moreira RG, Sun X, Chen Y. 1997. Factors affecting oil uptake in tortilla chips in deep-fat frying. J. Food Eng. 31, 485– 498.

Mudawi HA, Elhassan MSM, Sulieman AME. 2014. Effect of frying process on physicochemical characteristics of corn and sunflower oils. Food Public Health 4, 181-184.

Nazarbakhsh V, Ezzatpanah H, Tarzi BG, Givianrad MH. 2014. Chemical changes of canola oil during frying under atmospheric condition and combination of nitrogen and carbon dioxide gases in the presence of air. J. Am. Oil Chem. Soc. 91, 1903-1909.

Osawa CC, Gonçalves LAG. 2012. Changes in breaded chicken and oil degradation during discontinuous frying with cottonseed oil. Cienc. Tecnol. Aliment. 32, 692-700.

Oztop MH, Sahin S, Sumnu G. 2007. Optimization of microwave frying of potato slices by using Taguchi Technique. J. Food Eng. 79, 83-91.

Paul S, Mittal GS. 1996. Dynamics of fat/oil degradation during frying based on optical properties. J. Food Eng. 30, 389- 403.

Pérez-Camino MC, Márquez-Ruiz G, Ruiz-Mèndez MV, Dobarganes MC. 1991. Lipid changes during the frying of frozen prefried foods. J. Food Sci. 56, 1644–1647.

Perkins EG. 1967. Non-volatile decomposition products in heated fats and oils. Food Technol. 21, 611-16.

Rehab FMA, El Anany AM. 2012. Physicochemical studies on sunflower oil blended with cold pressed tiger nut oil during the deep frying process. Grasas Aceites 63, 455-465.

Rossell JB. 2001. Frying: Improving Quality. Woodhead Publishing, Cambridge.

Sahin S, Sumnu SG. 2009. Advances in deep fat frying of foods. CRC Press, New York.

Sahin S, Sumnu G, Oztop MH. 2007. Effect of osmotic pretreatment and microwave frying on acrylamide formation in potato strips. F. Sci. Food Agric. 87, 2830-2836.

Sebastian A, Ghazani SM, Marangoni AG. 2014. Quality and safety of frying oils used in restaurants. Food Res. Int. 64, 420-423.

Sebedio JL, Bonpunt A, Grandgirard A, Prevost J. 1990. Deep fat frying of frozen prefried foods: Influence of the amount of linolenic acid in the frying medium. J. Agric. Food Chem. 38, 1862–67.

Serjouie A, Tan CP, Mirhosseini H, Che Man YB. 2010. Effect of vegetable-based oil blends on physicochemical properties of oils during deep-fat frying. Am. J. Food Technol. 5, 310-323.

Siddique BM, Ahmad A, Ibrahim MH, Hena S, Rafatullah M, Omar AKM. 2010. Physico-chemical properties of blends of palm olein with other vegetable oils. Grasas Aceites 61, 423-429.

Tseng YC, Moreira R, Sun X. 1996. Total frying-use time effects on soybean-oil deterioration and on tortilla chip quality. Int. J. Food Sci. Technol. 31, 287-294.

Velasco J, Marmesat S, Dobarganes MC. 2009. Chemistry of frying, in Sahin S and Sumnu SG (Eds.) Advances in Deep-Fat Frying of Foods. 1st ed. CRC Press, Boca Raton, pp. 33-51.

Yoshida H, Tatsumi M, Kajimoto G. 1991. Relationship between oxidative stability of vitamin E and production of fatty acids in oils during microwave heating. J. Am Oil Chem. Soc. 68, 566-570.

Zambiazi RC, Przybylski R, Zambiazi MW, Mendonça CB. 2007. Fatty acid composition of vegetable oils and fats. B. CEPPA, Curitiba, 25, 111-120.

Zhang Q, Saleh ASM, Shen Q. 2016. Monitoring of changes in composition of soybean oil during deep?fat frying with different food types. J. Am. Oil Chem. Soc. 93, 69-81.

Ziaiifar AM, Achir N, Courtois F, Trezzani I, Trystram G. 2008. Review of mechanisms, conditions, and factors involved in the oil uptake phenomenon during the deep-fat frying process. Int. J. Food Sci. Technol. 43, 1410–1423.

Zribi A, Jabeur H, Aladedunye F, Rebai A, Matthaus B, Bouaziz M. 2014. Monitoring of quality and stability characteristics and fatty acid compositions of refined olive and seed oils during repeated pan- and deep-frying using GC, FT-NIRS, and chemometrics. J. Agric. Food Chem. 62, 10357-10367.

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