Appendix Linolenic Acid

Linolenic Acid Determine as directed under Fatty Acid Composition, Appendix VII. 

Lead Determine as directed under Method II in the Atomic Absorption Spectrophotometric Graphite Furnace Method under the Lead Limit Test, Appendix IIIB, using a 1-g sample. Linolenic Acid Proceed as directed under Fatty Acid Composition, Appendix VII. 

Although these are termed essential fatty acids, they are, in fact, precursors for the major polyunsaturated fatty acids that have essential roles in the body but are present only in small amounts in the diet. Linoleic acid is converted, via elongation and desaturation reactions, to dihomo-y-linolenic (20 3n-6) and then to arachidonic (20 4n-6) acid. a-Linolenic is converted to eicosapentaenoic (20 5n-3) and then docosahexae-noic (22 6n-3). The pathways for formation of these latter fatty acids, from their dietary precursors, are presented in Figures 11.11 and 11.12. Full details of one pathway are provided, as an example, in Appendix 11.4. For comparison of the two pathways, they are presented side by side in Figure 11.13. 

Identification Low linolenic flaxseed oil exhibits the following composition profile of fatty acids as determined under Fatty Acid Composition, Appendix VII. 

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