Fatty acid profiles of 80 vegetable oils with regard to their nutritional potential

The current concern for fat intake in western countries has raised the question of the individual fatty acid (FA) impact on health. This important issue has strengthened the awareness of nutritionists and food manufacturers for the control of the FA profile of food products. The aim of this review is to provide a classification of the FA profiles of 80 vegetable oil sources, according to their nutritional potential. The first part of the review focuses on lipoprotein metabolism, and on the impact of each dietary FA on blood lipid composition (LDL‐cholesterol, HDL‐cholesterol and circulating triacylglycerols). In the second part of the review, the oil sources are clustered by similar FA profiles, and the classification is discussed with regard to the individual FA action on blood lipid composition. Apart from the major vegetable seeds, the clustering highlighted some interesting nutritional oil sources containing mainly α‐linolenic acid (camelina, linseed, perilla and stock oils), or interesting amounts of the two essential FA (purslane, chia, raspberry seed, sea buckthorn seed and salicorn oils). Furthermore, this classification provides a useful tool for the formulation of the FA profile of food products.     

Composition of organic and conventionally produced sunflower seed oil

The aim of the present study was to highlight the main differences between seed oils produced from conventionally cultivated crops and organically cultivated ones and processed using mild extraction procedures. The composition and the nutritional and health aspects of both types of sunflower seed oils were compared and were analytically tested to determine the macroscopic differences in proximate composition, the main differences in the minor components, the main quality parameters, the in vitro antioxidant activity, and the presence of trans-ethylene steroisomers in FA. No significant trends were found in the oil samples for TAG and FA composition, but remarkable differences were found in the composition of minor components and in the main chemical and analytical quality properties. The organically grown samples had a higher total antioxidant activity compared with the conventional samples. Trans FA were found only in the conventional oils.     

Characterization of cold-pressed onion, parsley, cardamom, mullein, roasted pumpkin, and milk thistle seed oils

Cold-pressed onion, parsley, cardamom, mullein, roasted pumpkin, and milk thistle seed oils were characterized for their fatty acid (FA) composition, tocopherol content, carotenoid profile, total phenolic content (TPC), oxidative stability index (OSI), color, physical properties, and radical-scavenging capacities against peroxyl (oxygen radical-scavenging capacity) and stable DPPH (diphenylpicrylhydrazyl) radicals. Parsley seed oil had the highest oleic acid content, 81 g/100 g total FA, and the lowest saturated fat among the tested oils. Roasted pumpkin seed oil contained the highest level of total carotenoids, zeaxanthin, β-carotene, cryptoxanthin, and lutein at 71 μmol/kg and 28.5, 6.0, 4.9, and 0.3 mg/kg oil, respectively. Onion seed oil exhibited the highest levels of α- and total tocopherols under the experimental conditions. One of the parsley seed oils exhibited the strongest DPPH scavenging capacity and the highest oxygen radical absorbance capacity (ORAC) value of 1098 μmol Trolox equiv/g oil. However, ORAC values of the tested seed oils were not necessarily correlated to their DPPH scavenging capacities under the experimental conditions. The highest TPC of 3.4 mg gallic acid equiv/g oil was detected in one of the onion seed oils. The OSI values were 13.3, 16.9–31.4, 47.8, and 61.7 h for the milk thistle, onion, mullein, and roasted pumpkin seed oils, respectively. These data suggest that these seed oils may serve as dietary sources of special FA, tocopherols, carotenoids, phenolic compounds, and natural antioxidants. An erratum to this article is available at .     

Studies on Herbaceous Seed Oils XI

Seeds from eight species were analysed by standard procedures for oil and protein contents. The fatty acid composition of the oils was determined by GLC. Five species were found to contain oils above 20% and none of them is rich in protein. Some of the oils have a composition fairly similar to the oils at present in common use. Five seed oils are interesting in having more than 50% of saturated acids of the total fatty acids. T. involucrata seed seems to be a promising species because of its high oil and linoleic acid (61.7%) contents.     

Hybrid <Emphasis Type="Italic">Hibiscus</Emphasis> seed oil compositions

The seeds of cultivated Hibiscus spp. were extracted with supercritical carbon dioxide, and the resulting extracts were analyzed to identify the major TG components as the corresponding FAME. The seed oils were composed predominantly of oleic and linoleic FA (69.6–83.4%) with lesser amounts of palmitic acid (14.8–27.0%). Minor amounts of C14, C18, and C20 saturated FA were also detected. The oil content of the seeds was determined to be between 11.8 and 22.1 wt% for hybrid varieties and between 8.9 and 29.5 wt% for the native species from which the hybrid varieties were developed. The protein content of the defatted seed meal averaged 20% for the hybrid varieties. The composition of the extracted hibiscus seed oils suggests potential edible applications.     

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.     

Search for new industrial oils. I. Selected oils from 24 plant families

Summary The group of analyses used in this preliminary screening of oils has proved capable of indicating many seed species that contain oils of unusual or unknown composition. Some of the oils are characterized sufficiently to suggest probable commercial uses; others give no evidence of properties that would lead to their use while present commercial oils are in adequate supply. Still other oils are shown to have unknown composition, which must be determined before their potential value can be judged. The study as yet contains too few species to generalize about the relationship between botanical classification and oil composition. It does however provide numerous leads in the search for oils of industrial value. This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture. Agricultural Research Service, U. S. Department of Agriculture.     

Non-Edible Plant Oils as New Sources for Biodiesel Production

Due to the concern on the availability of recoverable fossil fuel reserves and the environmental problems caused by the use those fossil fuels, considerable attention has been given to biodiesel production as an alternative to petrodiesel. However, as the biodiesel is produced from vegetable oils and animal fats, there are concerns that biodiesel feedstock may compete with food supply in the long-term. Hence, the recent focus is to find oil bearing plants that produce non-edible oils as the feedstock for biodiesel production. In this paper, two plant species, soapnut (Sapindus mukorossi) and jatropha (jatropha curcas, L.) are discussed as newer sources of oil for biodiesel production. Experimental analysis showed that both oils have great potential to be used as feedstock for biodiesel production. Fatty acid methyl ester (FAME) from cold pressed soapnut seed oil was envisaged as biodiesel source for the first time. Soapnut oil was found to have average of 9.1% free FA, 84.43% triglycerides, 4.88% sterol and 1.59% others. Jatropha oil contains approximately 14% free FA, approximately 5% higher than soapnut oil. Soapnut oil biodiesel contains approximately 85% unsaturated FA while jatropha oil biodiesel was found to have approximately 80% unsaturated FA. Oleic acid was found to be the dominant FA in both soapnut and jatropha biodiesel. Over 97% conversion to FAME was achieved for both soapnut and jatropha oil.     

Application of seed oils and its bioactive compounds in sunscreen formulations

The photoprotective skincare products are in high demand to meet the consumer market with concern on skin health. Seed oils are commonly used as ingredients in many cosmetic products due to their natural antioxidants and now being increasingly recognized for their effects on skin health and photoprotection. This article briefly reviews the application of seed oils in sunscreen development focusing on the antioxidants that contribute to photoprotection, thus preventing UV-induced erythema and photoaging. The addition of seed oils that contain specific natural bioactive compounds was discussed in the review. Besides that, seed oils acting in molecular pathways that benefit photoprotection were also summarized. Seed oils (pomegranate seed oil, castor oil, cocoa butter, jojoba oil, rosehip oil, grapeseed oil, kenaf seed oil, and pumpkin seed oil) utilization have high potential to act as natural UV filters and at the same time help in skin repairing. The seed oils contributed beneficial properties to the sunscreen formulation due to their synergistic effect with antioxidants, antiaging properties, anti-inflammatory effect, and potential hormetic effect. The finding of specific bioactive compound from seed oils provides a better understanding of the contribution of seed oils in sunscreen formulation.     

Effect of sprouting on the quality and composition of canola seed and oil

Sprouting has been considered as a damage factor in grading canola. This project deals with the evaluation of the effect of sprouting on the quality and composition of canola seed and oil. Sprouted seeds had lower oil content than nonsprouted seeds as determined by exhaustive petroleum ether extraction. The difference, although statistically significant, was small, less than 0.1% oil at the maximum level of sprouting allowed in topgrade canola. There were no differences in chlorophyll contents or moisture contents between sound and sprouted seeds. Sprouted seeds had significantly higher levels of FFA and crude protein than sound seeds. Oxidation parameters (diene and aldehyde) were higher in oils from sound seeds than oils from sprouted seeds, but there was no statistically significant difference in PV. Sprouted seeds had higher levels of tocopherols and sucrose, but lower levels of raffinose, stachyose, and total sugars than sound seeds. There was no difference in overall FA composition of the oil between sound and sprouted seeds. The second extraction of the Federation of Oils Seeds and Fat Associations (FOSFA) extraction method, which allowed the extraction of more polar lipids, contained significantly more saturated FA. However, this was not significant in the overall FA composition of the oils because this fraction counted for about 2% of the total lipid content. The presence of sprouted seed had an effect on results for oil and crude protein determined by NIR as compared with results by FOSFA extraction, or pulsed NMR for oil and Dumas combustion for crude protein. Addition of sprouted seed samples to the NIR, calibration set overcame this problem. These results suggested that sprouting did not have a highly damaging effect on the quality and composition of canola seed and oil when less than 10% of the seeds in a sample were sprouting.     

Allanblackia Oil: Phytochemistry and Use as a Functional Food

The consumption and commercial exploitation of Allanblackia (Clusiaceae) seed oils is of current interest. The favorable physicochemical characteristics of Allanblackia oil (solid at room temperature; high stearic acid content) lend food products that contain it (i.e., vegetable-based dairy products, ice cream, spreads) health advantages over others that contain higher levels of lauric, myristic, and/or palmitic acids, which can increase blood cholesterol levels. Such considerations are important for individuals prone to cardiovascular disease or with hypercholesterolemia. Domestication projects of several Allanblackia species in tropical Africa are underway, but wildcrafting of fruits to meet the seed demand still occurs. Proper species authentication is important, since only authenticated oil can be deemed safe for human consumption. The chemical constituency of Allanblackia seed oils, and potential roles of these phytochemicals in preventive strategies (e.g., as part of a healthy diet) and as pharmacological agents used to treat chronic disease were examined in this review. The primary and secondary metabolite constituency of the seed oils of nearly all Allanblackia species is still poorly known. The presence, identity, and quantity of potentially bioactive secondary metabolites in the seed oils, and pharmacological testing of isolated compounds were identified as important directions for future research.     

Comparative Study of the Physicochemical Properties of FAME from Seed Oils of Some Native Species of Brazilian Atlantic Forest

The rapid decline in fossil fuel reserves in the world, rising oil prices, and growing concerns about the increase in pollutant gas emissions from this type of energy, have led to the exploration of new energy sources for the production of alternative fuels. The use of vegetable oils as a low‐cost raw material for biodiesel production is an effective way to reduce biodiesel costs. This paper reports on the production and biodiesel properties of the seed oils of six native species belonging to different families of plants from the Atlantic Forest in northeast Brazil. The results are compared with those obtained from traditional crops such as soybean and olive. The relative oil content of the seeds ranged from 31.5 to 67.4 %, while the biodiesel yield from these oils ranged from 93.2 to 97.6 wt%. The fatty acid composition is mainly constituted of oleic acid in three species (Cissampelos andromorpha, Rauwolfia grandiflora, and Tabernaemontana flavicans), eicosenoic acid in two species (Serjania caracasana and Serjania salzmanniana) and palmitic acid in Protium heptaphyllum. The physicochemical parameters of oil (density, viscosity, % FFA, and % of linolenic acid) and biodiesel (density, viscosity, acid number, copper strip corrosion, flash point, sulfur content, sulfated ash, water, oxidative stability, free and total glycerin) were in agreement with ASTM 6751 and EN 14214 standards. The fatty acid composition, biodiesel yield, oil, and biodiesel properties of the six native species studied demonstrate the high potential for producing alternative fuel in conventional diesel engines.     

Diacylglycerol acyltransferase: A key mediator of plant triacylglycerol synthesis

Many plants deposit TAG in seeds and fruits as the major form of storage lipid. TAG production is of tremendous socioeconomic value in food, nutraceutical, and industrial applications, and thus numerous conventional and molecular genetic strategies have been explored in attempts to increase TAG content and modify the FA composition of plant seed oils. Much research has focused on the acyl-CoA-dependent reaction catalyzed by diacylglycerol acyltransferase (DGAT), which is an integral endoplasmic reticulum protein and has also been shown to be present in oil bodies and plastids. DGAT enzymes exhibit diverse biochemical properties among different plant species, many of which are summarized here. In addition to catalyzing a critical step in TAG biosynthesis, there is evidence that DGAT has roles in lipid metabolism associated with germination and leaf senescence. TAG can also be formed in plants via two different acyl-CoA-independent pathways, catalyzed by phospholipid: diacylglycerol acyltransferase and diacylglycerol transacylase. The current understanding of the terminal step in TAG formation in plants and the development of molecular genetic approaches aimed at altering TAG yield and FA composition of TAG are discussed.     

<Emphasis Type="Italic">Geranium sanguineum</Emphasis> (Geraniaceae) seed oil: A new source of petroselinic and vernolic acid

The occurrent of petroselinic acid (18∶1Δ6cis) in seed oils was believed to be limited to the Umbelliferae or Apiaceae, and a few other members of the Umbelliflorae. A major occurrence of petroselinic acid outside the Umbelliflorae must therefore be regarded as highly unusual and surprising. The seed oil of Geranium sanguineum, a member of the family Geraniaceae, has now been found to contain petroselinic and vernolic acids as major FA in its seed oil TAG. These unusual FA have not been reported previously as constituents of Geraniaceae seed oils. The structure and composition of the seed oil FA from G. sanguineum were determined by combined use of chromatographic (TLC, capillary GLC) and spectroscopic (IR, GC-MS) techniques. The double-bond position in petroselinic acid was located unambiguously by the characteristic mass fragmentation of its dimethyldisulfide (DMDS) adduct. The epoxy FA was identified as vernolic acid by co-chromatography and by the mass fragments formed during GC-MS of the products of the epoxy ring-opening reaction with BF₃ in methanol.     

The composition of edible oils modifies β-sitosterol/γ-oryzanol oleogels. Part I: Stripped triglyceride oils

The role of the fatty acid (FA) composition of triglycerides (TAGs) on sterol/sterol ester oleogels has been studied. Minor oil components of three vegetable oils with varying degrees of unsaturation (iodine values, IV) were removed. Typical oil quality parameters were determined before and after the treatment, and oleogels were produced using all six oils. Characteristic gel properties such as transition temperatures, mechanical properties and microstructure were tested. The results were compared regarding the impact of IV and the stripping procedure. Minor components were essentially removed during stripping, resulting in significantly different oil properties such as peroxide value, free FA and viscosity. However, peroxides formed rapidly in stripped flaxseed oil. Gel–sol transition temperatures and enthalpies were higher in gels from untreated oils and decreased with IV in samples with stripped oils. In contrast, the sol–gel transition was suppressed due to minor oil components in untreated oils. The effect of IV on gel formation was much less and linked to a lower solvent viscosity in more unsaturated oils. Nevertheless, gel firmness was significantly higher in oleogels from untreated oils and decreased slightly with IV in stripped oils. That was associated with differences in the arrangement of network building blocks, which was confirmed using atomic force microscopy. This study showed that the FA composition of TAGs has a limited effect on oleogel properties compared to those of minor oil components. The next part of this study focuses on modifying oleogel properties by adding selected minor components to stripped oils at varying concentrations.     

Possibilities of peanut,pecan and safflower seed oils as supplements for olive oil

Summary Samples of completely refined peanut oil, semirefined pecan oil, imported edible grade olive oil and crude safflower seed oil have been examined for composition, spectral transmittance and other properties. Compositions were determined by means of the modified Bertram oxidation method and application of the iodine-thiocyanogen number technique. None of the oils examined simulate olive oil in composition. Peanut and pecan oils appear capable of modification to produce a product chemically similar to olive oil and for certain purposes can replace olive oil without modification. The production of pecan oil under present market conditions with regard to prices for edible oils and seedling pecan nuts does not appear to be very attractive unless the costs of processing pecans for oil can be greatly reduced. Presented before the American Oil Chemists’ Society Meeting, Houston, Texas, April 30 to May 1, 1942.     

Rheological and thermal properties of soybean oils with modified FA compositions

Rheological and thermal properties of five soybean oils with modified FA compositions were studied. Viscosity decreased with increasing temperature at different rates for the different oils. Oil with a high-oleic acid content had higher viscosity and a greater rate of change than did oils with typical FA compositions, oil with low-saturated FA or low-linolenic acid content, or oil from lipoxygenase-free soybeans. The melting and crystallization behaviors of the oils were examined using DSC. The high-oleic acid oil and the oil with low-saturated FA content had different DSC profiles compared with the other oils. Specific heat capacities of oils were estimated using a mathematical model; the high-oleic acid oil had a higher specific heat value, and the low-saturated FA oil had a lower value than did the other oils.     

Determination of fatty acid composition of amaranthus species

Fatty acid compositions of the seed oils from eighteen vareties of amaranthus species have been determined after room temperature transesterification. Consistent with earlier studies, wide variations in the fatty acid composition are reported, and appear to be agronomically related. All variaties show significant levels (2–5%) of squalene and a combined linoleic acid and olaic acid occurrence of between 70–-80%. This study represents the frist reported fatty acid composition of grain amaranthus cultivated in West Africa.     

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.     

Whole-plant oils,potential new industrial raw materials

In an extensive screening program, 14 plant species have been identified which have good potential as hydrocarbon- and rubber-producing crops. These plants contain from 5 to 10% oil plus polymeric hydrocarbon on a dry weight basis. Since their dry matter yield should be 11,200 to 22,400 kg/ha/year, they would produce several times as much oil as conventional oilseed crops. In these plants, the oil is not concentrated in storage organs, i.e., seed or fruit tissue, but is distributed throughout the whole plant. Several species are lactiferous, with oil as a major component of the latex. A few which are of primary interest as potential new sources of natural rubber produce an equal yield of by-product oil. A prominent feature of most whole-plant oils is their large component of nonglyceride esters. Such oils could become valuable new feedstocks for production of plasticizers for rubber and plastics and new sources of waxes, long chain alcohols, sterols, terpenes, fatty acids, and other products. A petroleum refinery could be operated on whole-plant oils, and some species are being referred to as potential “gasoline trees.” Presented at the AOCS Meeting, St. Louis, May 1978.