Reaction Rate Dependence on Temperature and Moisture During Storage

storage at

temperature (C)

25.

moisture (%)

10.

reference conditions

T

ref

20.

M

ref

8.

kinetic parameters

k

Mref

0.1

c

M1

0.1

c

Mref

0.05

c

M2

0.01

axes ranges

T

min

0.

T

max

40.

M

min

0.

M

max

15.

k

min

0.

k

max

0.6

For chemical reactions and many biological processes in stored dried foods, the reaction rates depend on both the temperature and water activity, the latter determined by the moisture content. This dependence can be visualized in a 3D plot of rate constant-temperature-moisture content values, with their relationship generated with a nested model. It is assumed that the temperature dependence of the isothermal rate constant follows the exponential model, a simpler alternative to the Arrhenius equation, for which the two parameters for moisture dependence follow a similar type of exponential dependence.