effects
of unexplained variability in the observed response due to extraneous
factors were minimized by randomizing the order of experiments.
The design variables were enzyme concentration (A, 1–9%),
reaction time (B, 30–210 min), and reaction temperature (C,
30–60 C) while the response variable was TCC in the Zn–chlorophyll
extracts. The results obtained were used to create a quadratic
model to determine the correlation of data using the SPSS program
version 13