the handbook of food engineering practice crc press chapter 10 ...

of reaction systems involved in food quality loss are not followed to sufficient reaction
extent, resulting in inaccurate reaction rate constants and undeterminable reaction orders. A
lot of valuable data cannot be utilized to their fullest extent and databases of food reaction
kinetic parameters contain a lot of uncertainties.
Figure 2. Effect of the Analytical Precision on the Accuracy of the
Estimated Reaction Rate Constant.
Another problem that scattered data can cause are values of R 2 obtained by the
zero order fit and by the first order fit that are practically indistinguishable. In the case of
the first order reaction the logarithms of the measured quanitites are used (semilog plot)
thus the R 2 is calculated for lny i and lny rather than y i and y (equation (15)). This in
effect tends to give a larger R 2 , especially if the larger scatter is at the larger values (Boyle
et al., 1974). This bias in the criterion might lead to a skewed preference to the first order
model. In these cases it is advisable to use additional criteria for goodness of fit, like
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