Quantitative Measure Of Sterilization

The rates of reactions in foods, such as the destruction of microorganisms or nutrients, are generally first-order reactions described by

where c is the concentration of any component at time t and kT is the rate constant at temperature T. The temperature dependency of the rate constant is given by the well-known Arrhenius law kT = k<fi-E°/RT

where k0 is a constant called frequency factor, Ea is the activation energy, and R is the gas constant. The temperature T normally varies in a heating process. To obtain the final concentration in changing temperature, equation 1 is integrated between initial concentration C; and final concentration c at time t to get

°IRTdt

In the food literature, equation 3 is used in a different form. Instead of referring to a final concentration, an equivalent heating time of F0 is used that gives the same final concentration when temperature T is constant at a reference value. For a reference temperature of TR, if the rate constant is kTn,

-EJRTg

When the process temperature T stays close to TR, equation 4 can be simplified by noting TTR T%. A new parameter Z is defined in terms of the activation energy Ea to describe the temperature dependence of reaction as

Berry Boosters

Acai, Maqui And Many Other Popular Berries That Will Change Your Life And Health. Berries have been demonstrated to be some of the healthiest foods on the planet. Each month or so it seems fresh research is being brought out and new berries are being exposed and analyzed for their health giving attributes.

Get My Free Ebook