3.2.1 Reaction Time
Figure 3.3 shows the changes in FFA content and the concentration of vitamin E extracted during course of enzymatic hydrolysis of PFAD with 70% v/w of water, by Aspergillus niger lipase at 65. The lipase concentration of 10% w/w hydrolyzed the acylglycerols in the PFAD rapidly for the first 6hrs and FFA in the reaction mixture increased from an initial content of 88.72% to 93%. The hydrolysis reaction achieved its equilibrium after 5hrs of reaction time and the FFA levels in the resulting mixture reached a maximum of about 93.31%. similar pattern of changes was observed in the concentrations of vitamin E extracted. Initial concentration of vitamin E in the PFAD was 0.41%, and neutralization of PFAD concentrated to 2.45%. Hydrolysis of the acylglycerols in the PFAD further increased the concentration of vitamin E extracted from the hydrolyzed PFAD from 2.45 % to 6.99% after 5hr of reaction time. Reaction was carried out at temperature of 65 \(\pm\) 1 . It was observed that at increased reaction time beyond 5hr, the concentrations of vitamin E began to decrease, shrinking back gradually. This may be caused by the oxidation of some vitamer within the vitamin E complex (or a portion of the vitamin E) released due to prolonged heating time. On the other hand, FFA released began to drop very sluggishly at prolonged time (>5hr). This may be attributed to the limitation of active sites on the PFAD available for lipase to release more FFAs during hydrolysis.
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Figure 3.3 Effect of changes in FFA content as a function of reaction time
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Figure 3.4 Effect of changes in FFA content as a function of reaction time