Thermal Conductivity of Pear, Sweet‐cherry, Apricot, and Cherry‐plum Juices as a Function of Temperature and Concentration

Abstract

The thermal conductivity of 4 fruit (pear, sweet‐cherry, apricot, and cherry‐plum) juices was measured with a coaxial‐cylinder (steady‐state) technique. Measurements were made, temperature range 20 to 120 °C, at concentrations between 12.2 and 50 °Brix. The uncertainty of the thermal conductivity measurements was estimated to be less than 2%. A semitheoretical method for the prediction of thermal conductivity of juices was proposed. It was found that the prediction Model IV, λ (T, x)/λ (T0, x) = (T/T0)n, where λ is the thermal conductivity, x is the concentration, and T is the temperature, developed in this work can be adopted with satisfaction. The thermal conductivity of juices can be predicted just by knowing the thermal conductivity λ0 at a reference temperature T0.

Simultaneous estimation of the thermophysical properties of three kinds of fruit juices based on the measured result by a transient heat flow probe method

“…Some researchers reported the thermal conductivity of fruit juice (Constenla et al, 1989;Telis-Romero et al, 1998;Zainal et al, 2000;Muramatsu et al, 2000;Magerramov et al, 2006). Constenla et al (1989) and Muramatsu et al (2000) measured the specific heat of apple juice using a calorimeter.…”

A compilation of correlation parameters for predicting the enthalpy and thermal conductivity of solid foods within the temperature range of −40°C to +40°C

“…There are many studies reporting food thermal property data that did not fit these criteria and these are therefore not included in this paper. Examples of excluded data include studies on meat products (Wang and Kolbe, 1990;Sweat et al, 1973;Baghe-Khandan and Okos, 1981;Kumbhar et al, 1981;Barrera and Zaritzky, 1983;Karunakar et al, 1998;Tsai et al, 1998;Zheng et al, 1998), dairy products (Reddy and Datta, 1994;Kim and Bhowmik, 1997;Tavman and Tavman, 1999), fruits and vegetables (Sweat, 1974;Wang and Brennan, 1992;Rapusas and Driscoll, 1995;Halliday et al, 1995;Donsì et al, 1996;Delgado et al, 1997;Njie et al, 1998;Shrivastava and Datta, 1999), liquids (Telis-Romero et al, 1998;Azoubel et al, 2005;Magerramov et al, 2006;Tansakul and Chaisawang, 2006;Coimbra et al, 2006), porous foods (Kostaropoulos and Saravacos, 1997;Muramatsu et al, 2007), bakery products (Rask, 1989;Baik et al, 2001;Ará -mbula-Villa et al, 2007) and ice cream (Cogné et al, 2003). If measured data are unavailable, predictions of thermal properties of solid foods from their composition can be obtained using the computer programme COSTHERM (Miles et al, 1983).…”