Measurement of Thermal Conductivity of Apple at Different Moisture Contents


Article Preview

Based on idealized non-steady state transient heat conduction model, the thermal conductivities of apple samples were determined at various moisture contents by using a specifically designed apparatus. The apparatus is rapidly, simply, accurately and only has relatively small sample requirement. Experimental data of thermal conductivities of apples showed a tendency of linear increase with the increase of moisture content of apple sample at the same temperature. An empirical correlation model for the thermal conductivity of apple as a function of moisture content was obtained. The developed model can be used to predict the thermal conductivity of apple satisfactorily in the entire range of moisture content. The results can be better contributed to the food engineering application.



Advanced Materials Research (Volumes 225-226)

Edited by:

Helen Zhang, Gang Shen and David Jin




M. Zhang et al., "Measurement of Thermal Conductivity of Apple at Different Moisture Contents", Advanced Materials Research, Vols. 225-226, pp. 556-559, 2011

Online since:

April 2011




[1] S. C. S. R. de Moura, S. P. M. Germer, D. C. P. Jardim and M. S. Sadahira. Thermophysical properties of tropical fruit juices. Brazilian Journal of Food Technology, 1(1–2) (1998), 70–76.

[2] J. E. Lozano, E. Rotstein and M. J. Urbicain. Shrinkage, porosity and bulk density of foodstuffs at changing moisure content. J. Food Sci., 48(1983), 1497.

[3] C. A. Miles, G. van Beek and C. H. Vcerkamp. Calculation of thermophisical properties of foods. In Physical Properties of Foods, ed. R. Jowitt. Applied Science Publisher, UK. (1991).

[4] N. N. Mohsenin. Thermal properties foods and agricultural materials. New York: Gordon and Breach Science Publishers (1980).

[5] M. S. Rahman, X. D. Chen and C.O. Perera. An improved thermal conductivity prediction model for fruits and vegetables as a function of temperature, water contedt and porosity. Journal of Food Engineering, 31(1997), 163-170.


[6] X.G. Liang, X.S. Ge, Y.P. Zhang and G.J. Wang. A convenient method of measuring the thermal conductivity of biological tissue. Phys. Med. Biol., 36(12) (1991), 1599-1605.

[7] S.S. Shyam and M. S. Rahman. Using neural networks to predict thermal conductivity of food as a function of moisture content, temperature and apparent porosity. Food Research International, 36(2003), 617-623.


[8] S. D. Ali, H. S. Ramaswamy and G. B. Awuah, G. B. Thermophysical properties of selected vegetables as influenced by temperature and moisture content. Journal of Food Process Engineering, 25(2002), 417–433.


[9] V. E. Sweat. Thermal properties of foods. In M. A. Rao & S. S.H. Rizvi (Eds. ), Engineering properties of foods(2nd ed. ). New York. Marcel Dekker. (1995).

[10] J. H. Blackwell. A transient-flow method for determination of thermal constants of insulating materials in bulk. Journal Apply Physica, 23(1954), 137-144.

[11] E. G. Murakami, V. E. Sweat; S. IS. Sash-y, E. Kolbe and K. Hayakawa; A. Datta. Recommended design parameters for thermal conductivity probes for nonfrozen food materials. Journal of Food Engineeting, 21 (1996), 109-123.


[12] S. X. Cheng, Y. F. Jiang and X. G. Liang. A tiny probe for measuring the thermal conductivities of non-rigid materials. Measurement Science Technology, 5(1994), 1339~1344.


[13] Haifeng Zhang, Gang Zhao and Hong Ye. An improved hot probe for measuring thermal conductivity of liquids. Meas. Sci. Techno., 16(2005), 1430–1435.


[14] M. Zhang, H. Z Zhao and J. Xie. Study on Measurement System of Thermal Conductivity of Vegetables and Fruits. Transactions of the Chinese Society of Agricultural Machinery , 37(2006), 90-93.