Improved Analytical Method for Determination of Cholesterol-Oxidation Products in Meat and Animal Fat by QuEChERS Coupled with Gas Chromatography-Mass Spectrometry.

Cholesterol is widely present in animal fats and meat products and can undergo oxidation to form cholesterol-oxidation products (COPs) during heating. The objective of this study was to develop a QuEChERS method for the determination of COPs in edible animal fats and meat products via gas chromatography-mass spectrometry in which the required solvent volume and extraction time were reduced. By employing a DB-5MS capillary column (30 m × 0.25 mm i.d., 0.25 μm film thickness) and a temperature-programming method, seven COPs, cholesterol, and the internal standard 5α-cholestane could be separated within 19 min. The limits of detection and limits of quantitation based on the COP standards ranged from 0.16 to 180 ng/mL and from 0.32 to 400 ng/mL, respectively, and the recoveries ranged from 89.1 to 107.6% for boiled pork and from 80.5 to 105.6% for lard. The intraday variabilities for boiled pork and lard ranged from 2.27 to 6.87% and from 1.52 to 9.78%, respectively, whereas the interday variabilities ranged from 1.81 to 7.89% and from 3.57 to 9.26%, respectively. Among the various meat samples, fish showed the highest level of COPs (31.84 μg/g). For the edible fats, the COP contents in tallow (22.79-60.15 μg/g) were much higher than those in lard (0.152-2.55 μg/g) and butter (0.526-1.36 μg/g). Collectively, this method can be applied to determine COPs in cholesterol-containing foodstuffs.