Does Soil Salinity Affect Yield and Composition of Cottonseed Oil?

Variation in the yield and composition of oil of cotton (Gossypium hirsutum) seed collected from two different sites (saline and non-saline) of Pakistan was examined. Hexane-extracted oil content of cottonseed from saline and non-saline areas was found to be 17.7 and 18.6%, respectively. No significant (P > 0.05) differences in the refractive index (40 °C), color, specific gravity (24 °C), iodine, free fatty acid, peroxide, unsaponifiable matter, saponification, conjugated diene and triene and p-anisidine values of the oils of cotton plants from saline and non-saline habitats were observed. Fatty acid compositional analysis showed the concentration of stearic (C_18:0) and oleic (C_18:1) acids to be significantly (P ≤ 0.05) higher, whereas that of linoleic (C_18:2) acid was lower in cottonseed oils from the saline area than those from the non-saline habitat. Tocopherol contents of cottonseed oils were significantly (P ≤ 0.05) higher from the saline area than those from the non-saline area. The results of the present study showed that soil salinity did not affect the oil yield of cottonseed, however, it significantly (P ≤ 0.05) affected the tocopherol and fatty acid profiles of the oils examined.     

Fatty Acids,Tocopherols and Sterols of <Emphasis Type="Italic">Cephalocroton cordofanus</Emphasis> in Comparison with Sesame,Cotton, and Groundnut Oils

Cephalocroton cordofanus, a perennial much-branched shrub, is dominant in the eastern and western states of Sudan. The seeds of C. cordofanus sesame, groundnut, and cotton were compared for their oil and protein content as well as for fatty acids, tocopherols, and sterols. Fatty acids and sterols were analyzed by GC while tocopherols were analyzed by HPLC. The oil of C. cordofanus showed low levels of saturated fatty acids in comparison with the other three oils. The other reported fatty acids of C. cordofanus were 8.60 % oleic, 17.2% linoleic, 64.2% vernolic, and 2.0% coronaric acids. Neutral lipids, glycolipids, and phospholipids of C. cordofanus oil accounted for 77.5, 14.4, and 8.1% of the total lipid fraction, respectively. The oil of C. cordofanus showed higher levels of tocopherols (113.53 mg/100 g) in comparison to sesame, groundnut, and cottonseed oils, with 64.74, 27.96, and 77.83 mg/100 g, respectively. The primary tocopherol of C. cordofanus was γ-tocopherol (106.21 mg/100 g), which amounted to 93.8% of the total tocopherols. β- and δ-tocopherol were present at levels below 5.0 mg/100 g. In comparison to sesame, groundnut, and cottonseed oils, C. cordofanus oil contains more (304.4 mg/100 g) total sterols than ground nut (294.0 mg/100 g), but less than sesame (774.9 mg/100 g) and cotton seed (492.4) oils. Due to its high level of epoxy fatty acids, C. cordofanus oil is used for industrial rather than edible applications.     

Agronomic performance of high oleic,low linolenic soybean in Tennessee

Soybean oil hydrogenation alters the linolenic acid molecule to prevent the oil from becoming rancid, however, health reports have indicated trans-fat caused by hydrogenation, is not generally regarded as safe. Typical soybeans contain approximately 80 g kg⁻¹ to 120 g kg⁻¹ linolenic acid and 240 g kg⁻¹ of oleic acid. In an effort to accommodate the need for high-quality oil, the United Soybean Board introduced an industry standard for a high oleic acid greater than 750 g kg⁻¹ and linolenic acid less than 30 g kg⁻¹ oil. By combing mutations in the soybean plant at four loci, FAD2-1A and FAD2-1B, oleate desaturase genes and FAD3A and FAD3C, linoleate desaturase genes, and seed oil will not require hydrogenation to prevent oxidation and produce high-quality oil. In 2017 and 2018, a study comparing four near-isogenic lines across multiple Tennessee locations was performed to identify agronomic traits associated with mutations in FAD3A and FAD3C loci, while holding FAD2-1A and FAD2-1B constant in the mutant (high oleic) state. Soybean lines were assessed for yield and oil quality based on mutations at FAD2-1 and FAD3 loci. Variations of wild-type and mutant genotypes were compared at FAD3A and FAD3C loci. Analysis using a generalized linear mixed model in SAS 9.4, indicated no yield drag or other negative agronomic traits associated with the high oleic and low linolenic acid genotype. All four mutations of fad2-1A, fad2-1B, fad3A, and fad3C were determined as necessary to produce a soybean with the new industry standard (>750 g kg⁻¹ oleic and <30 g kg⁻¹ linolenic acid) in a maturity group-IV-Late cultivar for Tennessee growers.     

Comparison of the Structures of Triacylglycerols from Native and Transgenic Medium-Chain Fatty Acid-Enriched Rape Seed Oil by Liquid Chromatography–Atmospheric Pressure Chemical Ionization Ion-Trap Mass Spectrometry (LC–APCI-ITMS)

The sn position of fatty acids in seed oil lipids affects physiological function in pharmaceutical and dietary applications. In this study the composition of acyl-chain substituents in the sn positions of glycerol backbones in triacylglycerols (TAG) have been compared. TAG from native and transgenic medium-chain fatty acid-enriched rape seed oil were analyzed by reversed-phase high performance liquid chromatography coupled with online atmospheric-pressure chemical ionization ion-trap mass spectrometry. The transformation of summer rape with thioesterase and 3-ketoacyl-[ACP]-synthase genes of Cuphea lanceolata led to increased expression of 1.5% (w/w) caprylic acid (8:0), 6.7% (w/w) capric acid (10:0), 0.9% (w/w) lauric acid (12:0), and 0.2% (w/w) myristic acid (14:0). In contrast, linoleic (18:2n6) and alpha-linolenic acid (18:3n3) levels decreased compared with the original seed oil. The TAG sn position distribution of fatty acids was also modified. The original oil included eleven unique TAG species whereas the transgenic oil contained sixty. Twenty species were common to both oils. The transgenic oil included trioctadecenoyl-glycerol (18:1/18:1/18:1) and trioctadecatrienoyl-glycerol (18:3/18:3/18:3) whereas the native oil included only the latter. The transgenic TAG were dominated by combinations of caprylic, capric, lauric, myrisitic, palmitic (16:0), stearic (18:0), oleic (18:1n9), linoleic, arachidic (20:0), behenic (22:0), and lignoceric acids (24:0), which accounted for 52% of the total fat. In the original TAG palmitic, stearic, oleic, and linoleic acids accounted for 50% of the total fat. Medium-chain triacylglycerols with capric and lauric acids combined with stearic, oleic, linoleic, alpha-linolenic, arachidic, and gondoic acids (20:1n9) accounted for 25% of the transgenic oil. The medium-chain fatty acids were mainly integrated into the sn-1/3 position combined with the essential linoleic and alpha-linolenic acids at the sn-2 position. Eight species contained caprylic, capric, and lauric acids in the sn-2 position. The appearance of new TAG in the transgenic oil illustrates the extensive effect of genetic modification on fat metabolism by transformed plants and offers interesting possibilities for improved enteral applications.     

Pre-Ripening damage to cottonseed byaspergillus flavus is not influenced by seed coat permeability

Infection of cottonseed (Gossypium hirsutum L.) byAspergillus flavus and associated production of aflatoxins are problems in the arid portions of the United States cotton belt. The hard seed (impermeable to water) characteristic confers resistance to these problems in ripened cottonseed. Experiments were done to determine if low seed coat permeability to water or impermeability protect developing seeds from deterioration and aflatoxin formation. No differences were observed in the degree of seed deterioration in the various cotton lines that could be attributed to seed coat permeability. It is likely that, because the impermeable or low permeability phenotypes are expressed only upon seed ripening, these characteristics afford no protection to cottonseed against attack byA. flavus during seed development. To whom correspondence should be addressed at USDA/ARS, Dept. of Botany and Plant Pathology, Michigan State University, East Lansing, MI 48824-1312.     

Studies on Minor Seed Oils XII

Physico-chemical analysis of seven seeds of indigenous species of plants belonging to six different botanical families have been carried out with the help of UV, IR, TLC-GLC techniques. All the seed oils were found in agreement with the simple fatty acid composition i.e. linoleic-oleic-palmitic type. The chief components among unsaturated acids in the six seed oils are oleic and linoleic acids together forming 40.0-86.0 %. Polygonum sp. surprisingly is found to have combined content of oleic and linoleic acid 13.3 % only but having unexpected high amount of linolenic acid (37.8 %). Among saturated acids, palmitic acid was predominant acid found in the range of 10.0-483 %. This chemical screening of seed oils reveals that the species producing highly unsaturated oils merit attention for utilization as minor seed oils.     

Fatty acid and triacylglycerol compositions of seed oils of five Amaranthus accessions and their comparison to other oils

This paper reports the fatty acid and triacylglycerol (TAG) compositions of five Amaranthus accessions (RRC1011, R149, A.K343, A.K432, and A. K433) representing two species and a cross between one of these and a third species. Seed oils of these were analyzed by gas chromatography and reversed-phase high-performance liquid chromatography, and their compositional properties compared with buck-wheat (Fagopyrum esculentum), corn (Zea mays), rice bran (Oryza sativa), soybean (Glycine max L. Merr.), sesame (Sesamum indicum), quinoa (Chenopodium quinoa), and cottonseed (Gossypium hirsutum) oils. All Amaranthus accessions were relatively high in palmitic (21.4–23.8%) and low in oleic (22.8–31.5%) and linolenic (0.65–0.93%) acids when compared to most of the grain and seed oils. The fatty acid composition of Amaranthus accessions K343, K433, and K432 (group I) were different from R149 and RRC1011 (group II) in mono and polyunsaturated fatty acids, but the saturate/unsaturate (S/U) ratios were very similar. All Amaranthus accessions were similar in TAG type, but showed slight differences in percentage. High similarities in UUU, UUS, and USS composition were observed among Amaranthus K343, K433 and K432, and between R149 and RRC1011. The fatty acid compositions of Amaranthus oil (group I) and cottonseed oil were similar, but their TAG compositions were different. The grain and oilseed oils were different from each other and from the Amaranthus accessions oils in terms of fatty acid composition, S/U, and TAG ratios. The UUU, UUS, and USS percentages were very diverse in grain and seed oils. The percentages of squalene in the TAG sample from the Amaranthus accessions were 8.05% in K343, 11.10% in K433, 11.19% in K432, 9.96% in R149, and 9.16% in RRC1011. Squalene was also tentatively identified in quinoa and ricebran oils at levels of 3.39 and 3.10%, respectively.     

<Emphasis Type="Italic">Santalum </Emphasis><Emphasis Type="Italic">insulare</Emphasis> Acetylenic Fatty Acid Seed Oils: Comparison within the <Emphasis Type="Italic">Santalum</Emphasis> Genus

The sandalwood kernels of Santalum insulare (Santalaceae) collected in French Polynesia give seed oils containing significant amounts of ximenynic acid, E-11-octadecen-9-oic acid (64–86%). Fatty acid (FA) identifications were performed by gas chromatography/mass spectrometry (GC/MS) of FA methyl esters. Among the other main eight identified fatty acids, oleic acid was found at a 7–28% level. The content in stearolic acid, octadec-9-ynoic acid, was low (0.7–3.0%). An inverse relationship was demonstrated between ximenynic acid and oleic acid using 20 seed oils. Results obtained have been compared to other previously published data on species belonging to the Santalum genus, using multivariate statistical analysis. The relative FA S. insulare composition, rich in ximenynic acid is in the same order of those given for S. album or S. obtusifolium. The other compared species (S. acuminatum, S. lanceolatum, S. spicatum and S. murrayanum) are richer in oleic acid (40–59%) with some little differences in linolenic content.     

Quality and compositional studies of some edible leguminosae seed oils in Botswana

Seed oils were extracted with n-hexane from three edible Leguminosae seeds: Tylosema esculentum, Xanthocercis zambesiaca, and Bauhinia petersiana, giving yields of 48.2, 17.6, and 20.8% (w/w), respectively. Some physical and chemical parameters were determined to ascertain the general characteristics of the oils. The saponification and iodine values indicated that all three oil samples could be classified among the olive group of oils. This inference was supported by the results of the detailed fatty acid composition of the oils as determined by capillary gas chromatography. The ratio of total unsaturated to total saturated fatty acids in all three oil samples was approximately 70:30, with either oleic or linoleic acid being the dominant fatty acid. These results were in agreement with a proton nuclear magnetic resonance analysis of the fatty acid classes in the seed oils. Thus, the analysis served to justify the use of the three Leguminosae seed oils in food preparations. The work has further indicated that, with their attractive properties, the seed oils from T. esculentum, X. zambesiaca, and B. petersiana are good candidates for further studies to evaluate their future commercial prospects in the Southern African region.     

Effect of nitrogen and zinc fertilization and plant growth retardants on cottonseed, protein, oil yields, and oil properties

The increase in the population in Egypt makes it imperative to explore promising approaches to increase food supply, including protein and oil, to meet the needs of the Egyptian people. Cotton is the principal crop of Egyptian agriculture. It is grown mainly for its fiber, but cottonseed products are also of economic importance. Cottonseed is presently the main source of edible oil and meal for livestock in Egypt. Field experiments were conducted in two successive seasons at the Agricultural Research Center (Giza, Egypt) on cotton (Gossypium barbadense L. cv. Giza 75) to determine the effect of nitrogen (N) fertilizer rate (107 and 161 kg of N/ha applied as ammonium nitrate containing 33.5% N in two equal doses at 6 and 8 wk after sowing), together with foliar applications of plant growth retardants (mepiquat chloride “Pix”, chloromequat chloride “Cycocel”, and daminozide “Alar”, each applied once at 288 g active ingredient/ha, after 75 d from sowing) and zinc (Zn) (applied in chelated form after 80 and 95 d from sowing at 48 g of Zn/ha) on seed, protein and oil yields and oil properties of cotton. The higher N-rate, as well as the application of all growth retardants and Zn, resulted in an increase in cottonseed yield, seed protein content, oil and protein yields/ha, seed oil refractive index, unsaponifiable matter, and total unsaturated fatty acids (oleic and linoleic). These treatments tended to decrease oil acid value, saponification value, and total saturated fatty acids. The seed oil content tended to decrease as N-rate increased and increased with the application of all growth retardants and Zn. There were some differences between Pix, Cycocel, and Alar regarding their effects on the studied characters. The highest increase in seed, oil, and protein yields/ha was found with Pix, followed by Cycocel. The Cycocel treatment gave the lowest total saturated fatty acids oil content, followed by Alar.     

Composition of Catalpa ovata Seed Oil and Flavonoids in Seed Meal as Well as Their Antioxidant Activities

In view of the growing demand for vegetable oil, currently exploration of some non‐conventional oils is of great concern. This study firstly analyzed the contents of fatty acids, phytosterols, and tocopherols in Catalpa ovata seed oil collected from four different Provinces in China. Then the composition of flavonoids as well as their antioxidant activities in defatted seed meal was determined. The results showed that the relative oil content in C. ovata seeds ranged from 24.0 to 36.0 % and seed oil was mainly composed of fatty acids linoleic acid (43.4–50.1 %), α‐linolenic acid (23.8–24.4 %), and oleic acid (13.1–16.2 %). The content of unsaturated fatty acids was up to 85.0 %. Sterol in seed oil mainly contained campesterol, stigmasterol, and β‐sitosterol. β‐sitosterol accounted for 74.0 % of the total sterol. The tocopherol content was 173.0–225.7 mg/100 g. Defatted seed meal from Hubei Province showed the highest content of total flavonoids (11 mg/g) and the strongest activities for DPPH radicals scavenging, ABTS radicals scavenging, and ferric reducing antioxidant power compared with other defatted seed meal in this study. Seven flavonoids were identified from C. ovata seed meal. These results suggest that C. ovata seeds may be developed as a new source of oil and can also be properly used in pharmaceuticals and cosmetics.     

FA composition and regiospecific analysis of Acer saccharum (sugar maple tree) and Acer saccharinum (silver maple tree) seed oils

GC analysis was performed to determine regiospecific distribution and FA composition in seed oils of the Aceraceae species, Acer saccharum and A. saccharinum. The oil content in the seeds was low at 5.0% in A. saccharum and 5.8% in A. saccharinum, and the main FA were linoleic (30.8 and 29.4%), oleic (21.3 and 27.6%), palmitic (10.1 and 10.5%), and cis-vaccenic (9.4 and 7.9%) acids, respectively. In addition, both oils contained long-chain monoenes of the n−9 and n−7 groups, including 11-eicosenoic, 13-docosenoic, 15-tetracosenoic, 13-eicosenoic, and 15-docosenoic acids, whereas γ-linolenic acid accounted for 0.8% of total FA in A. saccharum, and 0.5% in A. saccharinum. Regiospecific analysis, performed using the methodology of dibutyroyl derivatives of MAG, indicated that linoleic, oleic, and linolenic acids were mainly esterified at the internal position of TAG in both seed oils, whereas long-chain monoenes of the n−7 group were almost exclusively esterified on the external positions.     

Studies on Minor Seed Oils VI

Seeds from five species fo various plant families have been analyzed for their oil contents and physico-chemical characteristics with the help of spectroscopic (UV, IR) and chromatographic (TLC-GLC) techniques. Out of the five seed oils examined here, only two oils, Ipomea cardiophylla and Echinochloa colona, were found to have good combined oleic-linoleic contents (> 60%). Lepidagathis trinervis was interestingly noted for high content of oleic acid (72%).     

Fatty Acid Profiles of Garuga floribunda,Ipomoea pes‐caprae,Melanolepis multiglandulosa and Premna odorata Seed Oils

The fatty acid profiles of the seed oils of four species from four plant families for which no or only sparse information on the fatty acid profiles is available are reported. The four seed oils are Garuga floribunda of the Burseraceae family, Ipomoea pes‐caprae, of the Convolvulaceae family, Melanolepis multiglandulosa of the Euphorbiaceae family, and Premna odorata of the Labiatae (Lamiaceae) family. Linoleic acid is the most abundant in three seed oils, except I. pes‐caprae in which oleic acid is most abundant. These two acids are overall the most abundant in all four seed oils studied. Of the four seed oils investigated, only G. floribunda contains minor amounts of a cyclic fatty acid (dihydrosterculic acid).     

Antipolymerization activity of oat extract in soybean and cottonseed oils under frying conditions

A methanolic extract of Noble oat (Avena sativa L.) was tested for its antipolymerization activity in soybean and cottonseed oils heated to 180°C for 10 h per day for 10 d and for its carry-through properties in fried bread cubes. The soybean and cottonseed oils containing 0.005 or 0.007% oat extract (based on total phenolic content) formed significantly lesser amounts of polar compounds with high molecular weight than did the oils containing 0.02% tertiary butyl hydroquinone (TBHQ), 1 ppm dimethylpolysiloxane (DMS) and oils containing no additives (control) as measured by high-performance size-exclusion chromatography. Fatty acid composition, also monitored, showed that oils with either level of oat extract maintained a significantly higher linoleic-to-palmitic acid ratio (18∶2/16∶0) than did the other treatments. Oil extracted from bread cubes fried (180°C) in oils containing TBHQ and oat extract and then stored at 60°C in the dark for up to 14 d had significantly lower (P≤0.05) peroxide values and higher (P≤0.05) 18∶2/16∶0 ratios than did oil extracted from cubes fried in oil containing DMS and in the control oil.     

Distribution of Δ5-olefinic acids in the triacylglycerols fromPinus koraiensis andPinus pinaster seed oils

Purified triacylglycerols (TAG) fromPinus koraiensis andP. pinaster seed oils, which are interesting and commercially available sources of Δ5-olefinic acids (i.e.,cis-5,cis-9,cis-12 18:3 andcis-5,cis-11,cis-14 20:3 acids) were fractionated by reversed-phase high-performance liquid chromatography, and each fraction was examined by capillary gas-liquid chromatography for its fatty acid composition. A structure could be assigned to more than 92% of TAG from both oils. In both instances, ca. 48% of the TAG were shown to contain at least one δ5-olefinic acid. In the great majority of TAG, our data showed that there is only one molecule of δ5-olefinic acid per molecule of TAG. This is compatible with theoretical calculations based on the proportion of total δ5-olefinic in the oils. Thecis-5,cis-9,cis-12 18:3 acid (14.2 and 8.6% of total fatty acids in the seed oils ofP. koraiensis andP. pinaster, respectively) and thecis-5,cis-11,cis-14 20:3 acid (1.1 and 8.1% of total fatty acids in the seed oils ofP. koraiensis andP. pinaster, respectively) are preferentially associated with two molecules of linoleic acid, and to a lesser extent, to one molecule of linoleic acid and one molecule of oleic acid, or two oleic acid molecules. However, several other combinations occur, each in low amounts. The distribution of δ5-olefinic acids in TAG is evidently not random. Combining these results with the known preferential esterification of δ5-olefinic acids to the 1,3-positions of TAG would suggest that most of these acids are present at only one of these positions at a time.     

Estimation of Protein and Fatty Acid Composition in Shell-Intact Cottonseed by Near Infrared Reflectance Spectroscopy

Rapid and accurate analysis of cottonseed protein content and the composition of fatty acids (especially, saturated fatty acids) is often required in cotton production and breeding programs. This study aimed to establish a set of effective estimation models for these parameters. Near infrared reflectance spectroscopy (NIRS) calibration equations using partial least-squares regression for protein concentration, oil concentration, and five fatty acids of shell-intact cottonseeds were established based on 90 varieties, and the prediction abilities of the calibration models were verified using 45 other varieties. The prediction abilities of the NIRS calibration equations were basically consistent with external validation results. Each equation was assessed based on the ratio of performance to deviation (RPD_p). Protein content and seed total fatty acid (STA) content had high RPD_p values (3.687 and 3.530, respectively), whereas cottonseed kernel total fatty acid (KTA) content, linoleic acid (18:2), stearic acid (18:0), myristic acid (14:0), and palmitic acid (16:0) exhibited relatively high RPD_p (2.866, 2.836, 2.697, 2.676, and 2.506, respectively). The calibration model for oleic acid (18:1) had a low RPD_p (1.945). The results indicated that NIRS can be used to rapidly determine contents of STA, KTA, protein, stearic acid (18:0), myristic acid (14:0), and palmitic acid (16:0) in shell-intact cottonseed.     

Tomato Seed Oil I Fatty Acid Composition,Stability and Hydrogenation of the Oil

Tomato seed oil was investigated to study their components of fatty acids, stability and hydrogenation conditions. The estimation of the fatty acids of tomato seed oil from Ace variety and tomato seed oil extracted from local waste in comparison with cotton seed oil (the most familiar edible oil in Egypt) - Giza 69 variety - extracted by n-hexane and oil obtained by pressing shows that more than 50% of the total fatty acids are linoleic. Palmitic acid was found in a range between 20% to 29% and oleic acid was in a range between 13% to 18%. Other fatty acids like stearic, arachidic, and linolenic acid were less than 3%. The induction periods (at 100°C) for oils of fresh, roasted and stored tomato seeds were found to be 7, 10, and 5 hours respectively. The hydrogenation conditions of crude tomato seed oil were 180°C, 3 kg/cm² and 0.2% nickel catalyst for three hours of hydrogenation to reach a melting point of 50.7°C and an iodine value of 42.     

Triacylglycerols of Apiaceae seed oils: Composition and regiodistribution of fatty acids

Oils from the seeds of caraway (Carum carvi), carrot (Daucus carota), celery (Apium graveolens) and parsley (Petroselinum crispum), all from the Apiaceae family, were analyzed by gas chromatography for their triacylglycerol (TAG) composition and fatty acid (FA) distribution between the sn‐1(3) and sn‐2 positions of TAG. Twenty‐two TAG species were quantified. Glyceryl tripetroselinate was the major TAG species in seed oils of carrot, celery and parsley, with levels ranging from 38.7 to 55.3%. In caraway seed oil, dipetroselinoyllinoleoylglycerol was the major TAG species at 21.2%, while the glyceryl tripetroselinate content was 11.4%. Other TAG species were linoleoyloleoylpetroselinoylglycerol and dipetroselinoyloleoylglycerol. Predominantly, TAG were triunsaturated (72.2–84.0%) with diunsaturates at 14.4–25.9%, and small amounts of monounsaturated TAG. Results for regiospecific analysis showed a non‐random FA distribution in Apiaceae for palmitic, petroselinic, linoleic and oleic acids. Petroselinic acid was predominantly located at the sn‐1(3) position in carrot, celery and parsley seed oils, while it was mainly at the sn‐2 position in caraway seed oil. The distribution of linoleic acid was opposite to that of petroselinic acid. Oleic acid was mostly located at the sn‐2 position, except for caraway, where it was evenly distributed between the sn‐1(3) and sn‐2 positions. Both the saturated FA, palmitic and stearic acid, were located mainly at the sn‐1(3) position. The presence of a high level of tripetroselinin in parsley seed oil (55.3%) makes it a potential source for the production of petroselinic acid.