Abstract
Enzymatic methods are simple and of low-cost, but are nevertheless little used in the determination of cholesterol in foods as the enzyme reacts with any sterol, present in the sample. As eggs
only have cholesterol, the objective of this study was to optimize an enzymatic method for the determination of cholesterol in eggs and compare it to a high performance liquid chromatography (HPLC) method. For both methods, the samples were saponified directly and the unsaponifiable matter extracted with hexane. For the enzymatic method, a test kit (LABORLAB S.A) was used and the absorbance read at 499 nm, 90 minutes after the reaction. For HPLC, a C18, 100 x 4.6 mm x 4 µm (Chromolith, Merck) column was used, the solvent being acetonitrile:2-propanol (85:15 v/v) with a flow rate of 2 mL/min. The methods were
validated according to recovery test, the use of egg standard reference material (SRM 1846, NIST), and repeatability. The mean result for the enzymatic method was 1363 ± 47 and for HPLC 1364 ± 40 mg/100 g of yolk. There were no significant differences (p>0.01) found between the results of the two methods.
Both methods are reliable for use in the determination of cholesterol in yolk...
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