Evaluation of a commercial enzyme-based serum cholesterol test kit for analysis of phytosterol and phytostanol products.
Plant sterols (phytosterols) have been shown to possess serum cholesterol-lowering properties. In recent years, several phytosterol-enriched functional food products have been developed and marketed. Some phytosterol products contain common unsaturated sterols and some contain a subset of phytosterols called phytostanols (saturated sterols, also called plant stanols). Current methods for the quantitative analysis of plant sterols are labor intensive and require sophisticated gas or liquid chromatographs. In this study, a popular commercial spectrophotometric serum cholesterol test kit was evaluated for the analysis of plant sterols. The results indicate that the method could be modified to analyze phytosterols and phytostanols by increasing the incubation time. Both free phytosterols and fatty acyl phytosteryl esters were quantitatively analyzed, but ferulate phytosteryl esters, such as those that are found in corn and other cereals, were not hydrolyzed by the enzymes in the test kit and therefore were not detected.
US Department of Agriculture, Eastern Regional Research Center, Agricultural Research Service, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA. rmoreau@arserrc.gov
Robert A
RA
Moreau
Michael J
MJ
Powell
Kevin B
KB
Hicks
D002784:Cholesterol / Q000097:blood*; D002789:Cholesterol Oxidase; D002851:Chromatography, High Pressure Liquid; D004798:Enzymes; D005504:Food Analysis / Q000379:methods; D006868:Hydrolysis; D009195:Peroxidase; D010840:Phytosterols / Q000032:analysis*; D011933:Reagent Kits, Diagnostic; D013053:Spectrophotometry; D002787:Sterol Esterase; D013997:Time Factors
D004798:Enzymes; D010840:Phytosterols; D011933:Reagent Kits, Diagnostic; D002784:Cholesterol; D002789:Cholesterol Oxidase; D009195:Peroxidase; D002787:Sterol Esterase