To develop and utilize the oil of Pinus seeds and explore natural resources rich in pinolenic acid (PNLA), twenty-one Pinus taxa were evaluated in a search of Δ5-unsaturated polymethylene-interrupted fatty acids (Δ5-UPIFA)-rich oils. While the fatty acid (FA) composition was determined by GC-FID and GC-MS, NMR of crude oils proved to be a fast method for establishing the ratio between Δ5-UPIFA and total FA. For all analyzed taxa, both the geographical origin and the concentration of total FA in the seeds are provided. PNLA and sciadonic acids occurred in all samples, while taxoleic and bishomopinolenic acids were present in most taxa. PNLA reached a maximum of 28.3% of total FA in P. mugo, and P. koraiensis showed the highest total FA amount (66.8 g/100 g seeds). The previously unanalyzed taxon P. ponderosa var. scopulorum can be considered a new PNLA source (17.1%). Principal Component Analysis showed that the similarities in FA profiles allow the grouping of the various taxa within Pinus subsections and confirmed the differential metabolic activities of Δ5 and Δ9 desaturase enzymes. This study showed that several underutilized Pinus taxa could be developed into renewable woody oil species, and their seeds could be used as raw materials for Δ5-UPIFA-rich oils extraction.
Keywords: Fatty acids; GC-FID; NMR; Pinaceae; Pinolenic acid; Pinus; Principal component analysis.
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