4 Conclusion
The application of RSM proved a valuable tool in the extraction of tocopherols, a substance with vitamin E activity and also the concentration of FFAs respectively from PFAD. Experimental design enables the identification of important process parameters and hence their effects by statically describing the interactions of the select variables. The hydrolytic action on PFAD for the extraction of tocopherols and FFA using commercially immobilised lipase (Aspergillus niger) proved to be an efficient, and cost saving method of producing bio-active compounds from the by-product of deodorization stage of vegetable oil processing.