Color Changes Kinetics and Heat Transfer during Deep Fat Frying of Garlic Slice

Document Type: Research Paper


1 Assistant Professor of the Department of Biosystem Engineering, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran.

2 Assistant Professor of the Department of Food Science and Engineering, Azadshahr Branch, Islamic Azad University, Azadshahr, Iran.


Heat and mass transfer phenomena that take place during frying cause physicochemical changes, which affect the colour and surface of the fried products. The effect of frying temperature on the colour changes and heat transfer during deep fat frying of garlic has been investigated. The colour scale parameters redness (a*), yellowness (b*) and lightness (L*), and color change intensity (∆E) were used to estimate colour changes during frying as a function of oil temperature and time. L* value of fried garlic decreased during frying but a* and b* values were increased. A first-order kinetic equation was used for each one of the three colour parameters, in which the rate constant is a function of oil temperatures. The results showed that oil temperature have a significant effect on the colour parameters. Different kinetic models were used to fit the experimental data and the results revealed that the power model was the most suitable to describe the color change intensity (∆E). Center temperature of garlic slice increased with increase in oil temperature and time during frying.


Baik, O. & Mittal, G. (2003). Kinetics of tofu color changes during deep-fat frying. LWT-Food Science and Technology, 36 (1), 43-48.

Maity, T., Bawa, A. & Raju, P. (2014). Effect of vacuum frying on changes in quality attributes of jackfruit (Artocarpus heterophyllus) bulb slices. International Journal of Food Science, 1-8.

Dueik, V., Robert, P. & Bouchon, P. (2010). Vacuum frying reduces oil uptake and improves the quality parameters of carrot crisps. Food Chemistry, 119 (3), 1143-1149.

Garayo, J. & Moreira, R. (2002). Vacuum frying of potato chips. Journal of Food Engineering, 55 (2), 181-191.

Gorinstein, S., Leontowicz, H., Leontowicz, M., Namiesnik, J., Najman, K., Drzewiecki, J., Cvikrová, M., Martincová, O., Katrich, E. & Trakhtenberg, S. (2008). Comparison of the main bioactive compounds and antioxidant activities in garlic and white and red onions after treatment protocols. Journal of Agricultural and Food Chemistry, 56 (12), 4418-4426.

Khalil, A. (1999). Quality of French fried potatoes as influenced by coating with hydrocolloids. Food Chemistry, 66( 2), 201-208.

Kozempel, M. F., Tomasula, P. & Craig, J.C. (1995). The development of the ERRC food process simulator. Simulation Practice and Theory, 2 (4), 221-236.

Krokida, M., Oreopoulou, V., Maroulis, Z. & Marinos-Kouris, D. (2001). Colour changes during deep fat frying. Journal of Food Engineering, 48 (3), 219-225.

Manjunatha, S., Ravi, N., Negi, P., Raju, P. & Bawa, A. (2014). Kinetics of moisture loss and oil uptake during deep fat frying of Gethi (Dioscorea kamoonensis Kunth) strips. Journal of Food Science and Technology, 51 (11), 3061-3071.

Mariscal, M. & Bouchon, P. (2008). Comparison between atmospheric and vacuum frying of apple slices. Food Chemistry, 107 (4), 1561-1569.

Nourian, F., Ramaswamy, H. & Kushalappa, A. (2003). Kinetic changes in cooking quality of potatoes stored at different temperatures. Journal of Food Engineering, 60 (3), 257-266.

Olech, Z. & Zaborska, W. (2012). A spectrophotometric assay for total garlic thiosulfinates content. Kinetic aspects of reaction with chromogenic thiols. Polish Journal of Food and Nutrition Sciences, 62 (1), 23-29.

Oyedeji, A., Sobukola, O., Henshaw, F., Adegunwa, M., Ijabadeniyi, A., Sanni, L. & Tomlins, K. (2017). Effect of Frying Treatments on Texture and Colour Parameters of Deep Fat Fried Yellow Fleshed Cassava Chips. Journal of Food Quality, 1-10.

Paul, S. & Mittal, G. (1996). Dynamics of fat/oil degradation during frying based on optical properties. Journal of Food Engineering, 30 (3-4), 389-403.

Prati, P., Henrique, C.M., Souza, A.S.d., Silva, V.S.N.d. & Pacheco, M.T.B. (2014). Evaluation of allicin stability in processed garlic of different cultivars. Food Science and Technology (Campinas), 34 (3), 623-628.

Salehi, F. (2017). Rheological and physical properties and quality of the new formulation of apple cake with wild sage seed gum (Salvia macrosiphon). Journal of Food Measurement and Characterization, 11 (4), 2006-2012.

Salehi, F. (2018). Color changes kinetics during deep fat frying of carrot slice. Heat and Mass Transfer, 54 (11), 3421-3426.

Salehi, F. & Amin Ekhlas, S. (2018). The effects of wild sage seed gum (Salvia macrosiphon) on the rheological properties of batter and quality of sponge cakes. Journal of Food Biosciences and Technology, 8 (2), 41-48.

Vélez-Ruiz, J., Vergara-Balderas, F., Sosa-Morales, M. & Xique-Hernández, J. (2002). Effect of temperature on the physical properties of chicken strips during deep-fat frying. International Journal of Food Properties, 5 (1), 127-144.

Yagua, C.V. & Moreira, R. G. (2011). Physical and thermal properties of potato chips during vacuum frying. Journal of Food Engineering, 104 (2), 272-283.

Yamsaengsung, R., Ariyapuchai, T. & Prasertsit, K. (2011). Effects of vacuum frying on structural changes of bananas. Journal of Food Engineering, 106 (4), 298-305.