Table 5 Effect of cooking and re-heating method on the cholesterol oxidation products (COPs) and ratio of COPs/cholesterol in chicken thigh at day 6

Cooking/re-heating method¹⁾	COPs (μg/100 g)						Total amount of COPs/cholesterol (%) ^***
Cooking/re-heating method¹⁾	7β-OH²⁾	7-keto	20α-OH	25-OH	Triol	α-epoxide^*	Total amount of COPs/cholesterol (%) ^***
Raw	nd³⁾	nd	nd	1.5±0.59	nd	nd^B	1.02±0.16^A
PR/PR	nd	nd	nd	9.1±15.72	71.5±123.81	33.4±57.84^B	0.12±0.15^B
PR/MW	nd	nd	nd	88.6±138.86	68.7±119.05	53.9±93.38^B	0.22±0.07^B
ST/ST	nd	nd	nd	10.4±17.94	43.7±75.66	33.4±57.89^B	0.12±0.11^B
ST/MW	nd	145.5±252.05	nd	91.4±109.68	nd	311.5±126.29^A	0.81±0.69^A
OG/OG	nd	126.1±218.35	nd	19.5±33.71	137.8±148.95	144.2±185.24^AB	0.35±0.23^B
OG/MW	nd	nd	nd	9.7±16.82	33.7±58.37	nd^B	0.03±0.06^B
CG/CG	1.9±3.23	nd	nd	2.8±4.79	37.8±65.50	23.3±40.11^B	0.05±0.04^B
CG/MW	nd	nd	nd	1.8±3.16	42.5±73.63	35.2±30.54^B	0.05±0.06^B
MW/MW	nd	nd	nd	17.4±30.16	92.2±159.63	174.0±150.91^AB	0.26±0.02^B

¹⁾ Cooking and re-heating method: PR, pan roasting; ST, steaming; OG, oven grilling; CG, charcoal grilling; MW, microwaving.
²⁾ Abbreviation: 7β-OH, 7β-hydroxycholesterol; 7-keto, 7-ketocholesterol; 20α-OH, 20α-hydroxycholesterol; 25-OH, 25-hydroxycholesterol; triol, cholestane-3β, 5α, 6β-triol; α-epoxide, cholesterol-5α and 6α-epoxide.
³⁾ nd=not detected.
^A,B Means±SE with different superscript in the same column differ significantly.
^* p<0.05
^*** p<0.001.