with the collaboration of Iranian Food Science and Technology Association (IFSTA)

Document Type : Research Article

Authors

Food Processing Engineering Department, Gorgan University of Agricultural Sciences & Natural Resources, Iran.

Abstract

Introduction: Color is the most important feature of food appearance, since it strongly affects consumer acceptance. The abnormal color is closely related to degradation of food quality or food spoilage. Various factors affecting color of the product include the composition and surface properties of the foodstuff, process conditions (temperature and time), and the type of pretreatment processes. Therefore, for the design of a new process, kinetic modeling is essential for extracting basic kinetic information in a system to predict changes. Intermittent irradiation is the novel processing method in food industry which the surface temperature of product is kept constant. Darkening process occur in the fruit slices during drying, resulting in undesirable color changes. Undesirable color variations can be attributed to Millard's browning reactions between sugar and amine compounds or ascorbic acid oxidation. Thermal degradation kinetic models define maximum maintenance conditions for qualitative factors to produce a safe food. Color descriptive models are known as zero order, first order, and fractional conversion model. The fractional conversion model represents the response rate required at a given time to complete a phenomenon. This modeling is necessary for designing online quality control systems for thermal processing in the food industry and preserving the apparent quality of the product by optimizing the most important drying parameters. In this study, the kinetic of color changes in apple slices was investigated, in order to maintain appearance quality of product during simultaneous infrared dry-blanching and dehydration with intermittent irradiation.

Materials and Methods: Apple slices (Golden Delicious Variety) were dried in three thicknesses of 5, 9 and 13 mm using three constant surface temperatures of 70, 75 and 80 ° C. Image acquisition of apple slices was made use of a flatbed scanner with an interval of 15 minutes during processing. The treated samples were placed on the scanner and then a black box was utilized so as to prevent the interferences of the peripheral lights. The images featured a 300 dpi quality and were saved in TIFF-24 bit format. The color analysis of the images was carried out in color space of L*a*b* by the use ImageJ software, version 1.6.0. The lightness parameter (L), redness (a), yellowness (b), the intensity of the color changes (∆E), chroma (Cr) and browning index (BI) were described during product processing using fractional conversion model. Equilibrium color parameters (Cf) were also used as an indicator to compare different process conditions. The fitting of the model was done using the curve fitting toolbox in the 2009 version of the MATLAB software with 95% confidence level (P

Keywords

Acevedo, N. C., Briones, V., Buera, P., & Aguilera, J. M. (2008). Microstructure affects the rate of chemical, physical and color changes during storage of dried apple discs. Journal of Food Engineering, 85(2), 222-231.
AOAC. )2000.( Official methods of analysis. 17th ed., Association of Official Analytical Chemists. Washington, DC, Unites States.
Cortes, H., Pardio, V., & Garcia, M. (1999). Color parameter changes in banana slices during osmotic dehydration. Drying Technology, 17(4-5), 955-960.
Dadalı, G., Kılıç Apar, D., & Özbek, B. (2007). Color change kinetics of okra undergoing microwave drying. Drying Technology, 25(5), 925-936.
De Corcuera, J. I. R., Cavalieri, R. P., & Powers, J. R. (2004). Blanching of foods Encyclopedia of agricultural, food, and biological engineering (pp. 1-5): Marcel Dekker, Inc New York.
Ergüneş, G., & Tarhan, S. (2006). Color retention of red peppers by chemical pretreatments during greenhouse and open sun drying. Journal of Food Engineering, 76(3), 446-452.
Krokida, M., Tsami, E., & Maroulis, Z. (1998). Kinetics on color changes during drying of some fruits and vegetables. Drying Technology, 16(3-5), 667-685.
Krokida, M. K., Maroulis, Z. B., & Saravacos, G. D. (2001). The effect of the method of drying on the colour of dehydrated products. International journal of food science & technology, 36(1), 53-59.
Liu, Y., Zhu, W., Luo, L., Li, X., & Yu, H. (2014). A mathematical model for vacuum far-infrared drying of potato slices. Drying Technology, 32(2), 180-189.
Maskan, A., Kaya, S., & Maskan, M. (2002). Effect of concentration and drying processes on color change of grape juice and leather (pestil). Journal of Food Engineering, 54(1), 75-80.
Maskan, M. (2001). Kinetics of colour change of kiwifruits during hot air and microwave drying. Journal of Food Engineering, 48(2), 169-175.
Nathakaranakule, A., Jaiboon, P., & Soponronnarit, S. (2010). Far-infrared radiation assisted drying of longan fruit. Journal of Food Engineering, 100(4), 662-668.
Pan, Z., Olson, D. A., Amaratunga, K., Olsen, C. W., Zhu, Y., & McHugh, T. H. (2005). Feasibility of using infrared heating for blanching and dehydration of fruits and vegetables. Paper presented at the 2005 ASAE Annual Meeting.
Ramallo, L., & Mascheroni, R. (2012). Quality evaluation of pineapple fruit during drying process. Food and Bioproducts Processing, 90(2), 275-283.
Romani, S., Rocculi, P., Mendoza, F., & Dalla Rosa, M. (2009). Image characterization of potato chip appearance during frying. Journal of Food Engineering, 93(4), 487-494.
Sturm, B., Vega, A.-M. N., & Hofacker, W. C. (2014). Influence of process control strategies on drying kinetics, colour and shrinkage of air dried apples. Applied Thermal Engineering, 62(2), 455-460.
Tan, M., Chua, K., Mujumdar, A., & Chou, S. (2001). Effect of osmotic pre-treatment and infrared radiation on drying rate and color changes during drying of potato and pineapple. Drying Technology, 19(9), 2193-2207.
Tsami, E., & Katsioti, M. (2000). Drying kinetics for some fruits: Predicting of porosity and color during dehydration. Drying Technology, 18(7), 1559-1581.
Velickova, E., Winkelhausen, E., & Kuzmanova, S. (2014). Physical and sensory properties of ready to eat apple chips produced by osmo-convective drying. Journal of food science and technology, 51(12), 3691-3701.
Wojdyło, A., Figiel, A., & Oszmiański, J. (2009). Effect of drying methods with the application of vacuum microwaves on the bioactive compounds, color, and antioxidant activity of strawberry fruits. Journal of agricultural and food chemistry, 57(4), 1337-1343.
Xiao, H.-W., Law, C.-L., Sun, D.-W., & Gao, Z.-J. (2014). Color change kinetics of American ginseng (Panax quinquefolium) slices during air impingement drying. Drying Technology, 32(4), 418-427.
Zhu, Y., & Pan, Z. (2009). Processing and quality characteristics of apple slices under simultaneous infrared dry-blanching and dehydration with continuous heating. Journal of Food Engineering, 90(4), 441-452. doi: http://dx.doi.org/10.1016/j.jfoodeng.2008.07.015
Zhu, Y., Pan, Z., McHugh, T. H., & Barrett, D. M. (2010). Processing and quality characteristics of apple slices processed under simultaneous infrared dry-blanching and dehydration with intermittent heating. Journal of Food Engineering, 97(1), 8-16
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