Fatty acid composition of oil from exotic corn breeding materials

The fatty acid composition of corn oil can be altered to meet consumer demand for “healthful” fats. The first step in altering the oils is to survey existing corn breeding materials for fatty acid composition. The Latin American Maize Project (LAMP), an international program designed to evaluate the agronomic characteristics of maize accessions in Latin American and U.S. germplasm banks for future use, provides useful starting materials. LAMP was based on the cooperative efforts of 12 countries. In a two-stage evaluation, the project identified the highest-yielding open-pollinated top 20% of populations, then approximately the top 5% of those 20%. Twenty of the populations from four countries with temperate climates were randomly selected for fatty acid analysis. The populations were from United States, Chile, Argentina, and Uruguay. Fifty S₁ lines from each population were randomly chosen for analysis for a total of 1,000 genotypes sampled. Statistical differences in fatty acid composition were computed among the 20 populations and among the four countries. The findings showed a wide range of fatty acid profiles present in unadapted, elite corn breeding materials with ranges for each fatty acid as follows: palmitic acid, 6.3–18.2%; stearic acid, 0.9–4.5%; oleic acid, 18.5–46.1%; linoleic acid, 36.6–66.8%; linolenic acid, 0.0–2.0%; and arachidic acid, 0.0–1.4%. Several populations were significantly different from the others. Some lines had unusual fatty acid compositions, including one with 8.3% total saturates and another with 20.2% total saturates. This study shows that existing corn breeding materials could be used to produce high- and low-saturate oils, but other methods would probably be required to produce a high-oleic corn oil.     

Fatty acid composition of thirty-five Icelandic fish species

Fat content and fatty acid composition were determined in 35 fish species caught in Icelandic waters from November 1987 to March 1988. These were not only commonly edible species, but also underutilized and less common species, in which the fatty acid composition have not been reported before. The variation int he fat content and the fatty acid composition was found to be large between and within species. The fat content and n-3 fatty acid content varies sevenfold and twentyfold, respectively. An inverse relationship was obtained between the n-3 fatty acids content and the total fat content of the fish species studied. We believe that the data reported here on 35 fish species can be useful for nutritionists and food scientists, to aid them in dietary formulation, nutrient labelling, processing and product developments, as well as for the consumers.     

Tocopherols in breeding lines and effects of planting location, fatty acid composition, and temperature during development

As the use of tocopherols as natural antioxidants increases, it is economically and agronomically important to determine the range, composition, and factors that affect their levels in oilseed crops, a major commercial source. In this study, tocopherols were quantified from seeds of wheat, sunflower, canola, and soybean. The breeding lines analyzed possessed a broad range of economically important phenotypic traits such as disease or herbicide resistance, improved yield and agronomic characteristics, and altered storage oil fatty acid composition. Complete separation of all four native tocopherols was achieved using normal-phase high-performance liquid chromatography with ultraviolet detection. Total tocopherol concentration among wheat germ oil samples ranged from 1947 to 4082 μg g⁻¹. Total tocopherol concentration ranges varied from 534 to 1858 μg g⁻¹ in sunflower, 504 to 687 μg g⁻¹ in canola, and 1205 to 2195 μg g⁻¹ among the soybean oils surveyed. Although the composition of tocopherols varied substantially among crops, composition was stable within each crop. Total tocopherol concentration and the percentage linolenic acid were correlated positively in soybean oils with modified and unmodified fatty acid compositions. Tocopherol concentration and degree of unsaturation were not correlated in sunflower or canola seeds with genetically altered fatty acid composition. These findings suggest that breeding for altered storage oil fatty acid composition did not negatively impact tocopherol concentrations in sunflower and canola as they apparently did in soybeans. When 12 soybean breeding lines were grown at each of five locations, significant correlations were observed among planting location, breeding line, tocopherol concentration, and fatty acid composition. Analysis of seeds that matured under three different controlled temperature regimes suggests that the relationship between tocopherol concentration level and unsaturated fatty acids in commodity (not genetically modified for fatty acid composition) oil types is due to temperature effects on the biosynthesis of both compounds.     

Fatty acid composition of seed oil triglycerides inCoincya (Brassicaceae)

Oil and triglyceride contents and fatty acid composition were determined for seeds in nine taxa belonging to the genusCoincya (Brassicaceae) on the Iberian Peninsula (Spain and Portugal). The oil content ranges from 11.1 to 24.6%, triglycerides from 68.7 to 88.5%. The major fatty acids were erucic (24.6–30.5%), linolenic (17.7–27.7%), linoleic (13.9–24.6%) and oleic acid (12.3–21.8%).     

Fatty acid composition, extraction, fractionation, and stabilization of bullfrog (Rana catesbeiana) oil

The oil extracted from the fat-storage organ (fat body) of the bullfrog (Rana catesbeiana) was characterized for its fatty acid composition. The main fatty acids were palmitic (18.1%), stearic (4.1%), myristic (2.7%), oleic (31.7%), and linoleic (12.9%) acids. Long-chain polyunsaturated fatty acids were also present in significant amounts, i.e., eicosapentaenoic (1.5%) and docosahexaenoic (4.7%), and were probably derived from the fish meal content of the diet. A partially fractionated oil was extracted from the homogenized and frozen fat body with an oleic acid content of 43.2%. The natural alkaloid boldine, added at 0.5 mg/g oil level, improved the oxidative stability by a factor ranging from 1.7 to 2.4, as assessed by the Oil Stability Index method between 90 and 110°C. The stabilization effect of boldine was higher than that of naringenin, morin, and quercitin and for the synthetic antioxidant butylated hydroxytoluene at the same concentration level.     

Environmental effects on fatty acid levels in soybean seed oil

FA composition determines the quality of vegetable oil. Soybean breeders have generated and used mutations in FA genes to develop altered FA profiles in the seed. However, the expression of the alleles and the relative activity of the gene products are often dependent on the environment, and these facts have hampered the breeding efforts. To investigate the environmental effect on FA composition of soybean seed oil in specific mutant material developed at the University of Guelph, a recombinant inbred line (RIL) population was developed from a cross between a low palmitate (16∶0) line and a high-stearate (18∶0) parent. The RIL population was field-tested across three environments over 2 yr. A combined ANOVA for FA composition was conducted to determine the year and location effects on the expression of FA alleles in this material. The results indicated that linolenic (18∶3) level was most vulnerable to the environmental changes. Year effects accounted for a greater amount of variance than location effects for 16∶0, 18∶0, and 18∶1, whereas location effects were more important than year effects for the relative amounts of 18∶2 and 18∶3. Genotype × environment (year, location) interaction effects were significant for the relative amounts of all five FA according to the combined ANOVA. Our results indicated that the extreme minimum daily temperatures during September seed fill period, rather than the means or the maximum temperature, may be responsible for the ratio of saturated vs. unsaturated FA in soybean oil.     

Fatty acid selectivity of lipases: Erucic acid from rapeseed oil

The fatty acid selectivity of several commercial lipases was evaluated in the hydrolysis of high-erucic acid rapeseed oil (HEARO). The lipase ofPseudomonas cepacia catalyzed virtually complete hydrolysis of the oil (94–97%), while that ofGeotrichum candidum discriminated strongly against erucic acid, especially in esterification. A two-step process is suggested for obtaining a highly enriched erucic acid in which theG. candidum lipase is employed to selectively esterify the fatty acid residues of unsaturated C-18, and shorter chain acids, from a mixture of HEARO fatty acids obtained from total hydrolysis of the oil withP. cepacia lipase.     

Fatty acid composition of some pine seed oils

The fatty acid composition of seeds from seven species of the genusPinus (P. pinaster, P. griffithii, P. pinea, P. koraiensis, P. sylvestris, P. mughus, andP. nigra) was established. Pine seeds are rich in oil (31–68% by weight) and contain several unusual polymethylene-interrupted unsaturated fatty acids with acis-5 ethylenic bond. These are thecis-5,cis-9 18:2,cis-5,cis-9,cis-12 18:3,cis-5,cis-11 20:2, andcis-5,cis-11,cis-14 20:3 acids, with a trace ofcis-5,cis-9,cis-12,cis-15 18:4 acid. Their percentage relative to total fatty acids varies from a low of 3.1% (P. pinea) to a high of 30.3% (P. sylvestris), depending on the species. The majorcis-5 double bond-containing acid is generally thecis-5,cis-9,cis-12 18:3 acid (pinolenic acid). In all species, linoleic acid represents approximately one-half the total fatty acids, whereas the content of oleic acid varies in the range 14–36% inversely to the sum of fatty acids containing acis-5 ethylenic bond. The easily available seeds fromP. koraiensis appear to be a good source of pinolenic acid: their oil content isca. 65%, and pinolenic represents about 15% of total fatty acids. These values appear to be rather constant.Pinus pinaster, which is grown on several thousand acres in the southwest of France, is an interesting source ofcis-5,cis-11,cis-14 20:3 acid (7% in the oil, which isca. 35% of the dehulled seed weight), an acid sharing in common three double bonds with arachidonic acid. Apparently,P. sylvestris seed oil contains the highest level ofcis-5 double bond-containing acids among pine seed oils that have ever been analyzed.     

Fatty acid composition of lipids from the contents of rock lobster (Panulirus cygnus) cephalothorax

The contents of rock lobster cephalothorax were analyzed for lipid content and fatty acid composition. They contain a diversity of saturated (35.5±0.5%), monounsaturated (26.3±1.7%), and polyunsaturated fatty acids, n-3 highly unsaturated fatty acids (11.5±0.5%) among them. The possibility of using these products as a supplement to fish and food animals’ diets is discussed.     

Production of FAME from acid oil,a by-product of vegetable oil refining

Simple alkyl FA esters have numerous uses, including serving as biodiesel, a fuel for compression ignition (diesel) engines. The use of acid-catalyzed esterification for the synthesis of FAME from acid oil, a by-product of edible vegetable oil refining that is produced from soapstock, was investigated. Soybean acid oil contained 59.3 wt% FFA, 28.0 wt% TAG, 4.4 wt% DAG, and less than 1% MAG. Maximum esterification occurred at 65°C and 26 h reaction at a molar ratio of total FA/methanol/sulfuric acid of 1∶15∶1.5. Residual unreacted species under these conditions, as a fraction of their content in unesterified acid oil, were FFA, 6.6%; TAG, 5.8%; and DAG, 2.6%. This corresponds to estimated concentrations of FFA, 3.2%; TAG, 1.3%; and DAG, 0.2%, on a mass basis, in the ester product. In an alternative approach, the acylglycerol species in soapstock were saponified prior to acidulation. High-acid (HA) acid oil made from this saponified soapstock had an FFA content of 96.2 wt% and no detectable TAG, DAG, or MAG. Optimal esterification conditions for HA acid oil at 65°C were a mole ratio of FFA/methanol/acid of 1∶1.8∶0.17, and 14 h incubation. FAME recovery under these conditions was 89% of theoretical, and the residual unesterified FFA content was approximately 20 mg/g. This was reduced to 3.5 mg/g, below the maximum FFA level allowed for biodiesel, by washing with NaCl, NaHCO₃, and Ca(OH)₂ solutions. Alternatively, by subjecting the unwashed ester layer to a second esterification, the FFA level was reduced to less than 2 mg/g. The acid value of this material exceeded the maximum allowed for biodiesel, but was reduced to an acceptable value by a brief wash with 0.5 N NaOH.     

Fatty acid selectivity of lipases: γ-linolenic acid from borage oil

The γ-linolenic acid (Z,Z,Z-6,9,12-octadecatrienoic acid, GLA) present in borage oil free fatty acids was concentrated in esterification reactions that were catalyzed by several preparations of the acyl-specific lipase ofGeotrichum candidum. In this manner, a 95% recovery of the GLA originally present in borage oil (25% GLA) was obtained as a highly enriched fatty acid fraction with a GLA content of >70%. Other fatty acids concentrated in this fraction were the monounsaturated fatty acids with chainlengths of C-20 and longer that were present in the oil. An immobilized preparation ofG. candidum on silica gel also was used for the enrichment of GLA in borage oil. In this instance, a 75% recovery of GLA was obtained, and the supported lipase was reusable (three cycles) with minimal loss in activity. Presented in part at the 84th Annual Meeting of the American Oil Chemists’ Society, Anaheim, California, May 1993.     

Determination of conjugated linolenic acid content of selected oil seeds grown in Turkey

Seeds originating from some Turkish sources were analyzed with respect to their characteristics and FA compositions. These seeds represented pomegranate (Punica granatum L.), bitter grourd (Momordica charantia L.), pot marigold (Calendula officinalis L.), catalpa (Catalpa bignonoides), bourdaine (Rhamnus frangula L.), Oregon grape (Mahonia aquifolium), sarsaparilla (Smilax aspera), mahaleb (Prunus mahaleb L.), black-thorn (Prunus spinosa L.), cherry laurel (Prunus laurocerasus L.), and firethorn (Pyracantha coccinea). Bitter gourd and bourdaine seeds contain more than 20% oil. Catalpa, bourdaine, Oregon grape, blackthorn, and cherry laurel seed oil contents ranged from 15 to 20%. In the seeds from plants belonging to the Rosacea family, oil content ranged from 4.5 to 18.5%. Among the seed oils analyzed, pot marigold had one of the lowest oil contents (5.9%). Pomegranate contained the highest amount of total conjugated linolenic acid (CLNA) (86.0%). Seed oils of bitter grourd, pot marigold, mahaleb, and catalpa were rich in CLNA: 60.0, 29.5, 27.6, and 27.5%, respectively. Bourdaine, Oregon grape, and sarsaparilla seeds contained low amounts of CLNA. On the other hand, mahaleb, bourdaine, catalpa, Oregon grape, sarsaparilla, cherry laurel, blackthorn, and firethorn seed oils are basically oleic and linoleic acid-rich oils and therefore have little drying ability (semidrying oil). The results show a potential for the use of endogenous Turkish seeds as a source of CLNA.     

Low-molecular weight organic composition of acid water from coconut oil soapstock

Soapstock from alkaline refining of coconut oil was acidified, and the resulting acid water after neutralization was subjected to gas chromatography, electron-ionization and chemical-ionization mass spectroscopy, and high-performance liquid chromatography. The chief low-molecular weight organic components were C₄−C₁₈ fatty acids, hydroxylated acids, and sugar alcohols. The prevalence of acids and total absence of phosphate compounds make coconut acid water different in composition from the acid waters from other soapstocks.     

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.     

Clarity of blends of double-fractionated palm olein with low-erucic acid rapeseed oil

Double-fractionated palm olein (DfPOo) fractions with iodine values (IV) of 60 and 65 were each blended with low-erucic acid rapeseed (LEAR) oil in various proportions. Clarities of the blends at different temperatures were determined. Maximum levels of DfPOo-IV60 and DfPOo-IV65 in blends that remained clear at 20°C for at least 120 d were 40 and 80%, respectively. At 15°C, the maximum levels were 10 and 40%, and at 10°C, 10 and 20%, respectively. At 5°C, only a blend of 10% DfPOo-IV65 in LEAR remained clear for 120 d. Maximum levels of DfPOo-IV60 and DfPOo-IV65 in blends that passed the cold test were 30% for both palm oleins. Maximum levels of the palm oleins in blends with LEAR were higher than those of blends with soybean oil. Cloud points were lower in palm olein/LEAR blends than those of palm olein/soybean oil blends, probably because LEAR contains less saturated fatty acids than soybean oil.     

Fat content and fatty acid composition of oils extracted from selected wild-gathered tropical plant seeds from Nigeria

As the search for alternative sources of food to alleviate hunger continues, this study was undertaken to determine the fat content and the fatty acid composition of 15 lesser-known wild tropical seeds gathered in Nigeria. Results were contrasted with five tropical soybean varieties (Glycine max). The fat content varies from less than 1% (Pterocarpus santalinoides, Daniellia ogea) to 59% (Entandrophragma angolense). The fatty acid composition of most of the wild and mostly leguminous seeds differed considerably, compared to the composition of tropical soybeans. The oil of Adansonia digitata, Prosopis africana, Afzelia lebbeck, Enterolobium cyclocarpium, and Sesbania pachycarpa contained high proportions of linoleic and oleic acid as well as palmitic and linolenic acid. Seeds of Milletia thonningii, Lonchocarpus sericeus, and S. pachycarpa were much higher in linolenic acid and relatively poor in linoleic acid, compared to soybeans. The content of saturated fatty acids was higher than that of soybeans, resulting in lower polyunsaturated/saturated (P/S) ratios (0.83–2.12) than observed in soybeans (P/S=3.4), with the exception of the composition of S. pachycarpa (P/S=3.15). Some of these less familiar wild seeds could be used as sources for industrial or edible oils, provided that possible toxic constituents could be removed.     

Study on the composition of rice bran oil and its higher free fatty acids value

The compositions of rice bran oils (RBO) and three commercial vegetable oils were investigated. For refined groundnut oil, refined sunflower oil, and refined safflower oil, color values were 1.5–2.0 Lovibond units, unsaponifiable matter contents were 0.15–1.40%, tocopherol contents were 30–60 mg%, and FFA levels were 0.05–0.10%, whereas refined RBO samples showed higher values of 7.6–15.5 Lovibond units for color, 2.5–3.2% for unsaponifiable matter, 48–70 mg% for tocopherols content, and 0.14–0.55% for FFA levels. Of the four oils, only RBO contained oryzanol, ranging from 0.14 to 1.39%. Highoryzanol RBO also showed higher FFA values compared with the other vegetable oils studied. The analyses of FA and glyceride compositions showed higher palmitic, oleic, and linoleic acid contents than reported values in some cases and higher partial glycerides content in RBO than the commonly used vegetable oils. Consequently, the TG level was 79.9–92% in RBO whereas it was >95% in the other oils studied. Thus, refined RBO showed higher FFA values, variable oryzanol contents, and higher partial acylglycerol contents than commercial vegetable oils having lower FFA values and higher TG levels. The higher oryzanol levels in RBO may contribute to the higher FFA values in this oil.     

Characterization of protein extracted from flaked,defatted, whole corn by the sequential extraction process

An investigation was conducted to identify and characterize protein extracted by 45% ethanol:55% 0.1 M NaOH from flaked, defatted, undegermed corn (Zea mays L.) during Sequential Extraction Processing (SEP). This new approach to corn milling, SEP, recycles the ethanol produced from the fermentation of cornstarch to upstream steps of protein extraction and the simultaneous extraction of corn oil and dehydration of the ethanol. About 10% of the protein was extracted by ethanol during counter-current-percolation oil extraction. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and amino acid analysis identified this protein as zein. Nearly 65% of the total protein was recovered by the process in the protein extraction step from soft dent corn (Pioneer 3377), medium-hard dent corn (Pioneer 3732) and high-lysine corn. The freeze-dried solids of the ethanol/alkali extracts from these corn hybrids contained about 80% crude protein (db). The amino acids were present in quantities similar to those in whole corn and markedly higher than those in corn gluten meal. These results indicate that SEP produces high-quality protein suitable for food and industrial uses. Paper presented at the Symposium on Oilseed Processing for Edible Food and Feed Products, 82nd Annual Meeting of the AOCS, May 12–15, 1991. Research Associate, Assistant Professor, and Professor, respectively.     

Oil content and fatty acid composition of seed oil from guayule plants with different chromosome numbers

Guayule, a perennial desert plant, is being developed for domestic production of natural rubber, a strategic commodity for which the United States presently depends totally on foreign sources. At present, rubber alone is not sufficient to make guayule a commercial crop, and additional revenues are being sought from by-products. Because guayule flowers profusely during several years of growth before it is harvested for rubber, seed may also contribute to the economics of guayule production. Seed from 120 plants, including 20 genotypes with 36, 37, 54 and 72 chromosomes, were analyzed for oil content and fatty acid composition. Oil content ranged from 17.1 to 30.5%. On average, seed from diploid and aneuploid plants (with 36 and 37 chromosomes) contained 40.4% more oil than the seed from polyploid plants. The oil consisted of four fatty acids—palmitic (8.7–11.5%), stearic (3.7–6.2%), oleic (6.5–13.9%) and linoleic (69.1–80.2%)—at all ploidy levels. Guayule seed oil was similar to the seed oil from high-linoleic safflower varieties. The use of genetic variation to increase seed yield and seed oil will depend on the absence of negative correlation between oil and rubber production.     

Fatty acid composition and its relationship with physicochemical properties of pecan (Carya illinoensis) oil

The composition and physicochemical properties of pecan (Carya illinoensis) kernels and oils from different native trees of the central region of Mexico were investigated. The main compositional characteristic of the kernel was the high lipid content (70–79% w/w on dry basis) with elevated concentration of oleic acid (55–75% w/w). The results confirmed the relationship in the biosynthesis of linoleic and linolenic acids from oleic acid existing in oilseeds. Our results indicate that in pecans such relationship is a function of pecan tree age. The proportion of oleic, linoleic, and linolenic fatty acids determined the oxidative stability, viscosity, and melting/crystallization behavior of pecan oil. In general, these properties in pecan oils were similar or superior to extra-virgin olive oil and unrefined sesame oil. Although all native pecan oils studied showed a significant concentration of oleic acid, a particular group of native Mexican pecan trees produces an oil with a fatty acid composition with the nutritional appeal that consumers demand nowadays (i.e., very high oleic acid, 60–75%), with excellent natural oxidative stability (i.e., induction time for oxidation between 8.5 and 10.8 h), and substantially higher concentrations of α-, γ-, and δ-tocopherol than in pecan varieties previously reported in the literature.