Degradation rules

Some nutrients, notably vitamins, tend to degrade during the shelf life of a product. You can define the rules for degradation in the Degradation Rule form.

The primary factors of degradation are product packaging material, stability of the nutrient itself and heat treatment. For example, vitamin C degrades faster than vitamin D and vitamin C degrades faster in plastic than in glass containers. The degradation can be modeled mathematically, provided you have access to the degradation constant that is derived by experiments. This value is used by the analysis calculation.

The nutrition information on a label needs to take into consideration the nutrient degradation as defined in the degradation rule.

To estimate the nutrient concentration at the end of the product’s shelf life, you model the rate of degradation using first order kinetic theory:

A is the concentration of the nutrient at the time, t.

is the initial concentration

k is the degradation constant. It is experimentally determined and takes into account any environmental variables such as temperature, moisture, pH, ingredients, and oxygen that affect the degradation rate.

The constants are derived for individual nutrients in formulas stored in various packaging materials and under typical storage conditions. Generally, the permeability of the package material is determined by moisture and oxygen. They are the important factors that influence the overall stability of nutrients.

The degradation rule is defined by entering the degradation constant, k for each parameter. An equation can be written to use the source parameter value as and the shelf life t. An equation also calculates the resulting concentration of the nutrient. The shelf-life, t, is a user-defined input specified on the Analysis form.

Use the Degradation Rule form to define the degradation constant for each parameter for a given combination of product and package type. For example, you can define a degradation rule for bottles, aluminum cans, etc. A typical use of the degradation rule is shown for these equations.

' Degradation Equation

Dim ao as Object
Dim val as Long
Dim num as Long

ao = RowTag(1, _OBJECTKEY, "AVERAGED")
num = DegradationRule()  *  _ANALYSISSHELFLIFE

if _ANALYSISPARAM = "VITC" then
   val =  ao * (2.71828128^(num)) ' rate equation in Optiva
else
    val = ao
end if
return val
End Function

The default value is 0 for no degradation