This file was created by scanning the printed publication. Errors identified by the software have been corrected; however, some errors may remain. The Composition of Oils in Pinus edulis Michael Blair, Telletha Valenski, Andrew Sykes, Russell Balda, and Gerald Caple1 Abstract.-Pinon nut oil was reacted with sodium methoxide in methanol to yield the free methyl esters. These methyl esters were analyzed by GC­ mass spectrometry. The pinon seeds are 60% by weight oil; of this oil 90% were unsaturated fatty acids with 41 % being mono 9-octadecenoic acid and 59% being 9, 12-octadecadienoic acid. Small amounts of palmitic acid and stearic acid, both saturated oils, were found, as were some C20 species. Preliminary studies indicated the actual oil constituents varied in pinon seeds from different areas. The highly unsaturated oil of Pinus edulis seeds might be a useful dietary supplement, with the current health concerns about the lowering of saturated fats in the diet. INTRODUCTION solvent (hexane) to extract the oil, and then filter­ ing the solution. The powder extraction was set Foraging birds such as Pinon Jays, Scrub Jays, aside to do a protein and carbohydrate analysis. and Clark's Nutcrackers, instinctively harvest After evaporating the solvent, the oil was pinon nuts for the high supplement of fat. They reweighed to give the percent oil in the seed, discriminate between good and bad seeds, cones which agreed with the range given in the intro­ with a large nwnber of good seeds, and trees that duction. For the preparation of methyl esters from prod uced cones with a large number of good seeds the oil extraction, triglycerides were reacted with (Vander Wall and Balda, 1977). The pinon nut Sodium Methoxide (Olsson, Urban; Kaufmann, provides the birds with good nourishment Peter; Hersolof C. Bengt). Methyl esters were throughout the cold winter months. This can also separated from the nut and characterized by be said for the Native peopl~ who also forage off GC/MS. Methyl linoleate, methyl oleate, methyl the nut. stearate, and methyl palmitate were purchased Here we report on the composition of oils from Aldrich Chemical and used as standards. found in the pmon nut. The percentage of oil GC-Mass Spectroscopy spectra were collected found 'in the pmon nut (Pinus edulis) is 58-62% on an HP 5890 Series II GC fitted with a 12m >I- (C.W Bedkin, L.B. Shires). We have determined the 0.2mm >I- 0.33um HP-I crosslinked methyl silicone ratios of saturated and unsaturated fats in pmon gun1 column interfaced to an HP 5971A Mass Se­ nuts by Gas chromotagraphylMass Spectroscopy lective Detector. (CC/MS) and compared these ratios to other com­ mercial oils. The seeds were found from different areas of the southwest which gave variations in RESULTS/CONCLUSION percentage of oil. In addition, a one seed analysis was done to make a comparison with larger quan­ The specific oils in Pinus edulis were character­ tities. ized as the methyl esters by CC/MS. This could be done on any quantity of pinon nuts, including a single nut analysis. Figure 1 is a typical CC/MS MATERIALS AND METHODS spectrum of a single nut analysis. We identified four major oils present in Pinus edulis plus a small After weighing the crushed nut, we separated percentage of higher C20 oils. The molecular the oil from the pinon nut by using ,a nonpolar weights and retention tilnes of these methyl esters 1 Department of Chemistry and Biology, Northern Arizona Univer­ sity, Flagstaff, AZ. 225 Composition of Oil Table 1.-Retentlon Times ot Methyl Esters (minutes). Palmitate L1nolenate L1noleate Oleate Stearate 7 294 296 298 i'r Mol.Wgt. 270 292 7 7 /.I! Shelled(Feb) 15.97 Shoulder 18.31 18.34 COITONSEED /j! Shelled (June) 17.42 Shoulder 19.22 19.38 1L L //A OLIVE • Saturated 18.77 18.85 19.05 Freezer Nuts 17.1 18.55 V V / /,/1 • Monounsaturated PEANUT Palmitate 270 17.19 • Dlunsaluraled 'L / L / Linolenate 292 18.82 .. f;) O:her Linoleate 294 18.92 SAFFLOWER V / / / .. Oleate 296 18.96 SESAME Stearate 298 19.04 V / / / ,. SOYBEAN / / V... are given in Table 1. The molecular weights and 'PINON" the retention times of methyl esters purchased 20 40 60 80 100 from Aldrich closely match the methyl esters found Figure 2.-Fat content of commercial oils Including plrion. in the pinon nut. The shelled nuts (Feb) were run under different GC conditions (higher Heliun1 Figure 2 compares the fat content of Pinus edulis to column pressure) accounting for the faster in re­ other common cODlffiercial oils (USDA Handbook tention times. The freezer nut sample obtained # 8). The graph shows the nut is high in unsatu­ from a commercially available source and of uni­ rated fat (90%), but has its own unique content of dentified history also contained an additional mono and diunsaturated fats. The exact ratio of the unsa tura ted oil at 18.55 min (asterisk-Figure 2). mono and diunsaturated esters were determined by digital transformation of the linoleate and oleate peaks and fitting the data to two Gaussian peaks using a commercially available computer program (Peak Fit). The relative amounts of linoleate to oleate esters are 59% to 41 % by this technique. 2GDOOOO Integration using the GC/MS software incorrectly determined the relative percentages as 44/56% for 241)000:: the linolea te/olea te ratio, almos t the opposite from above, due to poor resolution of these peaks. In the future we would like to develop a greater separation of the methyl esters using COMS. 2000COJ Preliminary evidence shows that a large nwnber of isomers exist for n1ethyl linoleate and methyl oleate. We would also like to know if seasonal changes cause the pmon nuts to have different 161J')coa percentage of oil. 1400COIJ LITERATURE CITED 120DO(J\J Bader, Alfred; Harvey, David; Nagarkatti, Jai. 1990. Aldrich Chemical Company, Inc. 100000') Bedkin, C. W; Shires, L. B. 1948. The Composition and Ii I' Value of pinon Nuts. Agricultural Experimental Station. New Mexico of A &'M State College, New Mexico. Christensen, Kerry M.; Whitham, Thomas C.; Balda, Russell GODCO] p. 1991. Discrimination among pinyon pine trees by Clark's Nutcrackers: effect of cone crop size and cone characters. Oecologia. 86: 402-407. Olsson, Urban; Kaufmann, Peter; Herslof, Bengt C. 1990. Multivariate optimization of a gas-liquid chroma­ 200QUO i tOh'Taphk analysis of fatty acid methyl esters of black oil. 505: 385- , currant seed Journal of Chromatography. r 394. 1'i:"e -) 17.(JO 1;.5J 1B.00 18.50 :9. co 19.50 20.00 2G::O Watt, Bernice K. 1963. Composition of Foods. Agriculture Figure 1.-Graph showing GC/MS characterization of methyl Handbook No.8. Agricultural Research Service. United esters. States Department of Agriculture. 8: 135. 226 .