Table 2.

Analytical methods that were adapted and used to control the quality of acid oils and fatty acid distillates.

Analytical method	Main referencea
Preparation of test sample
Fatty acid composition	Guardiola et al. [6]
Tocopherol and tocotrienol content	Aleman et al. [7]
Moisture and volatile matter	AOCS official method Ca 2d-25 [8]
Insoluble impurities	ISO 663:2017 [12]
Unsaponifiable matter	AOCS official method Ca 6b-53 [13]
Acidity (free fatty acid content) and acid value	ISO 660:2009 [14]
Lipid classes (%): polymeric compounds, acylglycerols and free fatty acids	IUPAC method 2508 [15]
Peroxide value	Commission regulation (EEC) 2568/91 and its amendments [17]
p-Anisidine value	AOCS official method Cd 18-90 [18]
Oxidative stability by Rancimat instrument	AOCS official method Cd 12b-92 [19]

^aFor some methods other references have been used, see the supplementary materials for the complete list of references. No particular reference was followed for the preparation of the test sample.