Rapid Method for Quantification of Cholesterol in Turkey Meat and Products

Abstract

A direct saponification method was developed to determine cholesterol quantitatively in turkey meat and its processed products at a detection limit of 10 ppm. Five solvents and two derivatizing agents were evaluated. The method involved direct saponification with ethanolic KOH, homogeneous-phase toluene extraction of unsaponifiables, derivatization of cholesterol to a trimethylsilyl ether and quantitation by gas chromatography with flame ionization detection using 5␣-cholestane as internal standard. Compounds were confirmed by gas chromatography-mass spectrometry.

Cholesterol Content and Methods for Cholesterol Determination in Meat and Poultry

“…Similar phenomena were discussed by Fenton (1992) and Lesellier (2001). For the purpose of cholesterol determination, (5%‐phenyl)‐methylpolysiloxane (HP‐5, HP‐5 ms, ZB‐5, SPB‐5, DB‐5, RTX‐5, HP‐Ultra2) with very low polarity has probably been the most commonly used stationary phase regardless of whether cholesterol was derivatized (Ulberth and Reich 1992; Rodriguez‐Palmero and others 1994; King and others 1998; Toivo and others 2001; Baggio and others 2002; Bowden and others 2009; Isidorov and Szczepaniak 2009; Schummer and others 2009). The film thickness of choice was 0.25 μm except when there was no derivatization (1.05 μm, King and others 1998).…”

“…Cholesterol can be derivatized to the TMS ether by many different reagents (see summaries by Fenton 1992 and Abidi 2001). King and others (1998) compared the TMS derivatization process by hexamethyldisilane (HMDS)/trimethylchlorosilane (TMCS) (Sigma, St. Louis, Mo., U.S.A.) and Sylon BTZ (N‐trimethylsilylimidazole [TSIM]/N,O‐bis(trimethylsilyl)acetamide [BSA]/TMCS 3:3:2) (Supelco, Bellefonte, Pa., U.S.A.) and reported that the results were comparable (not statistically tested); however, Sylon BTZ reagent was faster and consumed less solvent. In contrast, Nawar and others (1991), when optimizing the silylating conditions for cholesterol and its oxides with N,O‐bis(trimethylsilyl)trifluoroacetamide (BSTFA), BSTFA/1% TMCS, and Sylon BTZ, found that BSTFA/1% TMCS gave the maximum conversion of cholesterol within 1 h at 80 °C and provided superior silylation for 7α‐ and 7β‐diols compared with BSTFA only.…”

“…The derivatization, on the other hand, can create artifacts that contaminate detectors, especially FID (Fenton 1992; Osman and Chin 2006), and interfere with detection and quantification. With improvement in thermostability of fused silica columns with bonded and cross‐linked stationary phase, it seems unnecessary to prepare cholesterol derivatives in many cases (Ballesteros and others 1996; King and others 1998; Baggio and others 2002; Hwang and others 2003; Osman and Chin 2006; Dinh and others 2008). In these studies, free cholesterol peaks were well shaped with good reproducibility.…”

“…It is noteworthy, however, that the cholesterol content of the skin from enhanced chicken was about 10 to 15 mg/100 g lower than that of the skin from nonenhanced chicken (USDA 2011, data under review). Mechanically deboned poultry meat has a greater cholesterol content than hand‐deboned meat (Ang and Hamm 1982; King and others 1988; Wong and others 1993; Baggio and others 2002). Such an increase in cholesterol content is probably caused by the presence of bone marrow, which is similar to mechanically deboned beef (Kunsman and others 1981).…”

Dietary Effect of Artificial Zeolite on Performance, Immunity, Faecal Microflora Concentration and Noxious Gas Emissions in Pigs

“…The moisture, crude protein, crude fat and crude ash contents were then determined using the AOAC methods (AOAC, 2000). Additionally, the cholesterol concentration of the meat was determined according to the method described by King et al (1998) using a gas chromatograph (DS 6200, Donam Co., Seongnam, Gyeonggido, South Korea).…”