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Food Thermal Conductivity

Reference data and engineering information about food thermal conductivity for food and bio applications.

foodthermalconductivityData Table

Overview

Engineering reference data for Food Thermal Conductivity in food bio.

Key Formulas

pH

pH=log10[H+]pH = -\log_{10}[H^+]

Measure of acidity in food.

Water Activity

aw=PP0a_w = \frac{P}{P_0}

Ratio of vapor pressure of food to pure water.

Thermal Death Time

logN0N=tD\log\frac{N_0}{N} = \frac{t}{D}

Microbial reduction during heating.

Q10 Temperature Coefficient

Q10=(k2k1)10/(T2T1)Q_{10} = \left(\frac{k_2}{k_1}\right)^{10/(T_2-T_1)}

Rate change per 10°C temperature increase.

Variables

SymbolDescriptionUnit
pHpHAcidity level
awa_wWater activity
NNMicrobial countCFU
DDDecimal reduction timemin
Q10Q_{10}Temperature coefficient

Food Thermal Conductivity Data

Conduction as heat transfer takes place when there is a temperature gradient in a solid or stationary fluid medium. The thermal conductivity of food products varies significantly based on water content, temperature, and structural properties such as fiber orientation in meats.

31 rows
Thermal conductivity of selected food products at various temperatures
Food
Water Content(%)
Temperature(°C)
Thermal Conductivity(W/(m·K))
Apple, whole852–350.39
Apple, juice88200.56
Beef, freeze dried (1 bar)00.07
Beef, freeze dried (10⁻⁶ bar)00.04
Beef, lean (⊥ fibers)7970.48
Beef, lean (∥ fibers)7970.43
Butter15450.2
Cod8330.54
Egg, white350.58
Egg, yolk350.34
Fish, loin0–100.58
Grapefruit, whole300.45
Honey1320.5
Milk370.53
Milk, condensed240.57
Milk, skimmed20.54
Olive oil150.19
Pork (⊥ fibers)7550.49
Pork (∥ fibers)7550.44
Pork, fat250.15
Potato, raw flesh821–350.55
Poultry, broiler muscle704–250.41
Salmon7540.5
Salt900.25
Strawberry15–250.68
Sugars30–600.09
Turkey, breast (⊥ fibers)7530.5
Turkey, breast (∥ fibers)7530.52
Oil, vegetable/animal4–1800.17
Wheat flour9430.45
Whey800.64

Source: Engineering ToolBox

Key Observations

  • High water content foods (fruits, lean meats, fish) typically have thermal conductivities between 0.39–0.68 W/(m·K)
  • Fat-rich and dried products (butter, oils, freeze-dried meats) have significantly lower values (0.04–0.20 W/(m·K))
  • Anisotropy in meats: Thermal conductivity is higher perpendicular (∥) to muscle fibers than parallel (⊥) to them, reflecting the directional structure of muscle tissue
  • Freeze-dried beef under high vacuum (10610^{-6} bar) has very low conductivity (0.04 W/(m·K)) due to minimal gas conduction within the porous structure

Interactive Charts

Conductive Heat Transfer

References