Volume 8, Issue 4, August 2020, Page: 117-120
Investigation of the Effects of Repeated Frying on the Quality of Vegetable Oil
Maduelosi Ngozi Jane, Department of Chemistry, Rivers State University, Port Harcourt, Nigeria
Cookey Grace, Department of Chemistry, Rivers State University, Port Harcourt, Nigeria
Received: Sep. 22, 2019;       Accepted: Oct. 18, 2019;       Published: Aug. 31, 2020
DOI: 10.11648/j.ajac.20200804.13      View  51      Downloads  38
Refined vegetable oil (Kings brand), was purchased from Mile 3 Market, Port Harcourt, Nigeria and was repetitively used in frying Akara balls for a period of 24 hours, at intervals of four hours per day, for six days. The effect of heat and repetitive use for frying on quality of the oil was monitored by the measurement of the physico-chemial parameters of the oil after each frying period. The density, % free fatty acid, viscosity, peroxide value and iodine value of the fresh and used oil were determined to investigate the level of deterioration. The results obtained show that the values of the parameters increased with frying time except that of iodine value which decreased with frying time. The free fatty acid value increased from 0.06 -.56%, density increased from 0.900-0.910 g/ml, viscosity increased from 23.33-28.31mm2/s, peroxide value increased from1.988-4.879meqO2/Kg and iodine value decreased from 43.35 – 29.83wijis. These changes are attributed to the destruction of the chemical structures of the triacylglycerols and formation of new products in the oil by heat. The increase in the density and viscosity shows that as frying progressed, denser and higher molecular weight compounds are formed thereby rendering the used oil more viscous. The increase in peroxide values may be due the formation of peroxides as the primary products of oxidation. The formation of peroxides leads to loss of unsaturation in the oil which is seen as a reduction in iodine value of the oil. The sweet aroma of the oil was also lost as frying progressed as a result of de-esterification of the oil and formation of secondary oxidation products that impart off-flavours to the oil. The findings show that repeated use of vegetable oil for frying leads to deterioration/degration of the oil.
Oxidation, Physico-Chemical Parameters, Vegetable Oil, Frying, Akara Balls, Heat
To cite this article
Maduelosi Ngozi Jane, Cookey Grace, Investigation of the Effects of Repeated Frying on the Quality of Vegetable Oil, American Journal of Applied Chemistry. Vol. 8, No. 4, 2020, pp. 117-120. doi: 10.11648/j.ajac.20200804.13
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Covas, M. I. & Gaddi, A. V. Relationship of olive oil polyphenols and oxidation biomarkers. Journal of Nutrition. 2011, 141 (12) 2256.
Fekarurhobo, G. K., Obomanu, F. G., & Maduelosi, N. J. Effect of Short Term Exposure to Sunlight on the Quality of some Edible oils. Research Journal of Applied Sciences. 2009. 4 (5): 152-156.
Gotoh, N., Ai-Iwasawa, H., Watanabe, R., O. & Wada, S. Oxidation of Fats and Oils in instant noodles stored under various conditions. Journal of Food Lipids. 2007. 14, 350-365.
Maduelosi, N. J., Obediah, G. A. & Ogbonna, O. D. Effects of Vegetable Oil Reused for Frying on the Liver of Albino Rats. Science Journal of Chemistry. 2019. 7 (1). 11-14.
Cheman, Y. B. & Jasvir, I. Effect of Rosemary and Sage extracts on frying performance of refined, bleached and deodorized (RBD) Palm Olein during deep frying. Food Chemistry. 2000, 69, 301-307.
Gloria, H., & Aguilera, J. M. Assessment of the quality of heated oils by differential scanning calorimetry. Journal of Agriculture and Food Chemistry. 1998. 46, 1363-1368.
Choe, E. & Min, D. B. Chemistry of Deep-frying oils. 2007. Journal of Food Sciences. 72: 77-86.
Romero, A., Bastida, S. & Sanchez-Muniz, F. J. Cyclic fatty acid monomer formation in domestic frying of frozen foods in sunflower oil with high oleic acid. Food and Chemical Toxicology. 2006. 44: 1674-1681.
Garrido-Polonio, C., Garcia-Linares, M. C., Garcia-Arias, M. T., Lopes-Varela, S., Garcia-Katragadda, H. R., Fullana, A., Sidhu, S & Carbowell-Barrachina, A. A. Emissions of volatile aldehydes from heated cooking oils. Food Chemistry. 2009. 120, 59-65.
Cleark, W. L. & Serbia G. W. Safety aspects of frying fats and oil; Food Technology. 1991. 45 (2) 84-89.
Marinova, E. M., Seizova, K. A., Totseva, I. R., Panayotova, S. S., Marekor. I. N. & Momchilova, S. M. Oxidative changes in some vegetable oils during heating at frying temperature. Bulgarian Chemical Communications. 2012. 44 (1) 57-63.
Bhattacharya, A. B., Sajilata, M. G., Tiwari, S. R & Singhal, R. Regeneration of thermally polymerized frying oils with adsorbent. Food Chemistry. 2008. (110), 562-570.
Al-fatlawi, A. M. L., & Abbas, N. M. Investigating Peroxide and Acid value in used Edible vegetable oil. The Iraqi Journal of Agricultural Science. 2010. 41 (4): 13-132.
Maduelosi N. J., & Worlu G. E. Effect of Photo-Oxidized Groundnut oil (Arachis hypogea) on the Liver Enzymes of Albino Rats. International Journal of Advanced Research in Chemical Science. 2015. 2 (11) 5-7.
Reblova, Z. Rudrrova J. Trojahova L. & Pokorry. Unsaturated fatty acids as compared to saturated acid. Food lipids. 1999. 6.13.
Tynek, M., Hazuka, Z., Pawlowiz P. & Oudek, M. Loss of Unsaturation in the Composition of the Vegetable oil as Frying Progressed. Journal of Food Lipids. 2001. 8. 251.
Daya, G., Padmini, S. & Wind, R. Measurement of peroxides in oils and fats. Cons. Stand & home Eco. 2004. 24: 223.
American Oil Chemists Society (AOCS). Sampling and Analysis of Commercial Fats and Oils. Washington D. C, 1986.
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