Effect of Different Extraction Methods on Quality Characteristics of Rapeseed and Flaxseed Oils

Table 4

SPME-GCMS analysis of volatile compounds in rapeseed and flaxseed oils.

Oil sample	Extraction methods	Pretreatment	Volatile compounds (%)
			Acids	Aldehydes	Heterocycles	Alcohols	Alkanes	Esters	Ketones	Alkenes	Other
Rapeseed oil	Screw press	Hot	10.77	1.85	23.9	16.01	0.5	1.38	13.45	1.87	30.27
		Cold	17.75	15.12	11.12	13.03	0.87	1.63	3.99	1.58	34.91
	Hydraulic press	Hot	11.99	6.52	18.43	5.79	1.52	3.96	10.05	4.3	37.44
		Cold	43.22	22.62	—	18.29	3.26	—	12.6	—	0.01
	Soxhlet extraction	Hot	18.53	13.52	12.97	4.35	7.56	0.37	7.81	18.57	16.32
		Cold	6.62	16.83	7.96	8.18	10.12	4.2	7.78	4.44	33.87
Flaxseed oil	Screw press	Hot	32.27	34.77	12.06	9.5	2.92	3.32	2.68	—	2.48
		Cold	31.24	26.38	18.82	6.19	1.39	1.99	5.24	—	8.75
	Hydraulic press	Hot	5.36	1.97	46.79	4.69	1.2	3.75	2.18	31.52	2.54
		Cold	25.48	15.46	10.58	29.53	—	—	15.02	—	3.93
	Soxhlet extraction	Hot	21.62	9.94	10.17	3.51	7.31	5.81	20.76	3.18	17.7
		Cold	20.72	15.65	7.26	10.12	8.8	2.05	13.55	2.32	19.53

Note. —: less than 0.5% or undetectable.