An investivation of the extraction,refining and composition of oil from winged bean (Psophocarpus tetragonolobus [L.] D.C.)

Eleven winged bean accessions from Thailand were analyzed. Oil content ranged between 15 and 18%. Oleic and linoleic acids were the major fatty acids (62.5–64.5%) together with behenic (12.6–14.4%) and lignoceric acid (2.4–2.8%). Linolenic acid level was low and traces of 15-, 17- and 21-carbon acids (saturated and unsaturated) were found. No parinaric acid was detected. Campesterol, stigmasterol and β-sitosterol were the principal components of the unsaponifiable fraction. The extracted oil had a very low free fatty acid (FFA) content but was not completely liquid below 35 C. The refining of crude winged bean oil is reported. Oil produced by expeller had a strong, beany aroma but a negligible level of gums and a low level of FFA. Degumming and neutralizing were unnecessary; bleaching produced an attractive colored oil free from beany aroma. Crude solvent-extracted oils from whole and decorticated winged beans had appreciable contents of gums and higher FFA contents than expeller-produced oil. Laboratory refining demonstrated the strong interference on bleaching exerted by gums and FFA. Conventional refining by degumming, neutralizing, bleaching and deodorizing, and by physical refining produced high-quality oils having a good color, low FFA level and no taste or smell. The solid/liquid ratio of refined winged bean oil as a function of temperature was found to be unusual. Oil was extracted from whole and decorticated winged beans in a pilot solvent extraction plant designed to simulate a Rotocei. Winged bean flakes were not as mechanically strong as those from soybean but good oil extraction yields were obtained and a meal was produced having an oil content of less than 1% at 10% moisture. Whole winged beans were expelled in a small expeller (throughput 16.8 kg/hr). Cake was produced with a residual oil content of 3.3–5% in a single pass through the expeller.     

Effects of cooking and screw-pressing on functional properties of Cuphea PSR23 seed proteins

This investigation determined the effects of oil processing conditions on some functional properties of Cuphea PSR23 seed proteins to evaluate their potential for value-added uses. Flaked Cuphea seeds were cooked at 82°C (180°F) for 30, 75, or 120 min in the seed conditioner and then screw-pressed to extract the oil. Cooked flakes and press cakes were analyzed for proximate composition and protein functional properties. Results were compared with those of unprocessed ground, defatted Cuphea seeds. Protein from unprocessed Cuphea seeds had excellent emulsifying properties, poor foaming properties, poor solubility (10%) at pH 4–7, and much greater solubility at pH 2 and 10 (57 and 88%, respectively). Solubility profiles showed that cooking the flaked seeds to 82°C for 30 min resulted in a 50–60% reduction in soluble proteins. Cooking for 120 min gave <6% soluble proteins at all pH levels. Cooking for 75 min gave good oil yields but also resulted in <10% soluble proteins at pH 2–7 and 25% soluble proteins at pH 10. Seed cooking and screw pressing during oil extraction had significant detrimental effects on the solubility of Cuphea seed protein but generally improved its foaming capacity and emulsifying activity.     

Physico-Chemical Characteristics of Citrus Seeds and Seed Oils from Pakistan

The physico-chemical characteristics of the seeds and seed oils of four citrus species, Mitha (Citrus limetta), Grapefruit (Citrus paradisi), Mussami (Citrus sinensis), and Kinnow (Citrus reticulata) were investigated. The hexane-extracted oil content of citrus seeds ranged from 27.0 to 36.5%. The protein, fiber and ash contents were found to be 3.9–9.6%, 5.0–8.5%, and 4.6–5.6%, respectively. The extracted oils exhibited an iodine value of 99.9–110.0; refractive index (40 °C), 1.4639–1.4670; density (24 °C), 0.920–0.941 mg/mL; saponification value, 180.9–198.9; unsaponifiable matter, 0.3–0.5%; acid value (mg KOH/g of oil), 0.5–2.2 and color (1-in. cell) 1.4–3.0R + 15.0–30.0Y. The oils revealed a good oxidative stability as indicated by the determinations of specific extinctions at 232 and 270 nm (2.3–4.4 and 0.6–0.9, respectively), p-anisidine value (2.2–3.2) and peroxide value (1.6–2.4 mequiv/kg of oil). The citrus seed oils mainly consisted of linoleic acid (36.1–39.8%). Other prominent fatty acids were palmitic acid (25.8–32.2%), oleic acid (21.9–24.1%), linolenic acid (3.4–4.4%), and stearic acid (2.8–4.4%). The contents of tocopherols (α, γ, and δ) in the oil were 26.4–557.8, 27.7–84.1, and 9.1–20.0 mg/kg, respectively. The results of the present study demonstrated that the seeds of citrus species investigated are a potential source of valuable oil which might be utilized for edible and other industrial applications.     

Potential of <Emphasis Type="Italic">Jatropha curcas</Emphasis> as a Biofuel,Animal Feed and Health Products

Jatropha curcas is a multipurpose plant with numerous attributes. It can potentially become one of the world’s key energy crops. Its seed weighs 0.53–0.86 g and the seed kernel contains 22–27% protein and 57–63% lipid indicating good nutritional value. The seeds can produce crude vegetable oil that can be transformed into high quality biodiesel. Several methods for oil extraction have been developed. In all processes, about 75% of the weight of the seed remains as a press cake containing mainly carbohydrates, protein and residual oil and is a potential source of livestock feed. The highly toxic nature of whole as well as dehulled seed meal due to the presence of high levels of shells, toxic phorbol esters and other antinutrients prevents its use in animal diet. The genetic variation among accessions from different regions of the world and rich diversity among Mexican genotypes in terms of phorbol ester content and distinct molecular profiles indicates the potential for improvement of germplasm of Jatropha through breeding programs. The extracts of Jatropha display potent cytotoxic, antitumor, anti-inflammatory and antimicrobial activities. The possibilities on the exploitation potential of this plant through various applications have been explored.     

Chinese melon (Momordica charantia L.) seed: Composition and potential use

Chinese melon (Momordica charantia L.), also known as bitter gourd, is a tropical crop, grown throughout Asian countries for use as food and medicinals. In 1993, four cultivars of Chinese melon were grown in Mississippi and the seeds were collected. Oil contents of the seeds ranged from 41 to 45% and the oils contained 63–68% eleostearic acid and 22–27% stearic acid. Industrially important tung oil, a “fast-drying oil” used in paints and varnishes, contains 90% eleostearic and 2–3% stearic acid. The ratio of stearic to eleostearic in Chinese melon seed oil is ten times greater than that in tung oil. The higher ratio should reduce the rate of drying and crosslinking and could be advantageous in the paint industry. The defatted meals contained 52–61% protein and would be a good source of methionine.     

Characterization of yam bean (Pachyrhizus spp.) Seeds as potential sources of high palmitic acid oil

Seeds from 22 accessions of the yam bean species Pachyrhizus ahipa (14 accessions), P. erosus (5), and P. tuberosus (3) were investigated for oil and protein contents, fatty acid composition of the seed oil, and the total tocopherol content and composition. Plants from the accessions were grown under greenhouse conditions during one (P. erosus and P. tuberosus) or two years (P. ahipa). The pattern of the investigated seed quality traits was very similar in the three species. Yam bean seeds were characterized by high oil (from about 20 to 28% in one environment) and protein contents (from about 23 to 34%). Seed oil contained high concentrations of palmitic (from about 25 to 30% of the total fatty acids), oleic (21 to 29%), and linoleic acids (35 to 40%). Levels of linolenic acid were very low, from about 1.0 to 2.5%. Total tocopherol content was relatively low in P. erosus (from 249 to 585 mg kg⁻¹ oil) and P. tuberosus (from 260 to 312 mg kg⁻¹ oil) compared with the levels found in P. ahipa grown under identical conditions (508 to 858 mg kg⁻¹ oil). In all the samples, γ-tocopherol was predominant, accounting for more than 90% of the total tocopherol content. The combination of high oil and protein contents, together with high palmitic acid, low linolenic acid, and high γ-tocopherol concentration, makes these crops an interesting alternative as sources of high palmitic acid oil for the food industry.     

Peanut proteins as food supplements: A compositional study of selected Virginia and Spanish peanuts

Three peanut cultivars (Virginia, red-skinned, and white-skinned Spanish) were analyzed and compared as potential protein supplements for food uses. The seeds were solvent-extracted in the laboratory to yield defatted flours with 9–10% nitrogen contents. Protein isolates were prepared from the flours by subsequent extraction with dilute salt solutions buffered at pH 7.0. Various parameters were compared, such as total protein contents, soluble proteins, amino acid compositions of flours and protein isolates, free amino acids and free sugars of defatted flours, and certain trace minerals in flours and soluble proteins. The application of these results to the selection of certain types of peanuts for potential uses as protein supplements in food products is discussed. Presented in the Symposium, Oilseed Proteins, 66th Annual AOCS Meeting, Dallas, Texas, April 27–30, 1975.     

Characteristics and composition of six malvaceae seeds and the oils

The seeds ofSida veronicifolia Linn., syn.S. bumilis cav.,S. cordifolia Linn.,S. ovata Forsk.,S. mysorensis W & A., syn.S. urticaefolia W & A,S. rhombifolia var.retusa Masters andAbutilon crispum Medik. (Malvaceae) contained 15.5%, 11.5%, 12.1%, 13.2%, 20.2% and 12.5% oil, and 15.0%, 14.1%, 17.3%, 13.6%, 12.6% and 18.4% protein, respectively. Linoleic acid predominated (54.9–69.4%) as the fatty acid of all the oils, and malvalic (1.3–11.4%) and sterculic acids (0.4–1.1%) were significant.     

Fractionation and characterization of proteins from <Emphasis Type="Italic">Gevuina avellana</Emphasis> and <Emphasis Type="Italic">Rosa rubiginosa</Emphasis> seeds

Gevuina avellana and Rosa rubiginosa proteins were evaluated for their potential food use. The proteins were sequentially separated into five fractions according to their solubilities in deionized water, 0.5 M NaCl, 70% (vol/vol) isopropyl alcohol, 50% (vol/vol) glacial acetic acid, and 0.1 M NaOH. The five fractionated protein groups were then characterized by SDS-PAGE and gel filtration chromatography to determine their M.W. profiles. Ninety-six percent of G. avellana total protein was solubilized in three extraction stages, and 88% of R. rubiginosa total protein was solubilized in one extraction stage. Albumins were the major protein fraction in G. avellana and glutelins-1 the most abundant in R. rubiginosa. The protein solubility profile determined over the pH range 1–12 showed minimal solubilities at pH 3–5 and pH 3–7 for G. avellana and R. rubiginosa, respectively. Electrophoretic studies revealed the existence of proteins composed of two major kinds of polypeptides linked together via disulfide bonds and with molecular masses ranging from 13 to 119 kDa. Gel filtration chromatography profiles of globulins and albumins were studied for both seeds. Isoelectric focusing showed an isoelectric point in the ranges of 4.5–6 and 3–6.5 for G. avellana and R. rubiginosa proteins, respectively.     

Characterization and compositional studies of the oils from some legume cultivars, <Emphasis Type="Italic">Phaseolus vulgaris</Emphasis>, grown in Southern Africa

Seed oils from six legume cultivars of Phaseolus vulgaris, grown in the Kingdom of Lesotho, were extracted and their physicochemical properties and FA compositions were determined in order to compare their dietary lipids with those in P. vulgaris cultivars grown in other parts of the world. The oil content of the beans was very low, ranging from 1.5 to 2.0% (w/w). The acid values ranged from 11.0 to 19.2 mg KOH/g, whereas a combination of the PV and the p-anisidine values in Holm's equation gave oxidation values that ranged from 11.0 to 15.0. Thus, considerable enzymatic hydrolysis and oxidation had taken place in the beans during storage. Iodine values ranged from 80.5 to 92.3 (Wijs method), indicating moderate unsaturation in the oils. However, capillary GC analysis, supported by proton NMR analysis of the FAME, gave a total unsaturation range from 79.67 to 84.24%. The dominant FA were α-linolenic acid (36.47–48.81%) and linoleic acid (20.96–36.10%), with appreciable amounts of palmitic acid (14.33–18.23%). This FA composition pattern is quite similar to the FA distribution reported for low oil-bearing legume seeds. Thus, notwithstanding the different climatic and soil conditions, the general properties of lipids in the southern African legume cultivars were quite similar to those of lipids in P. vulgaris cultivars grown in other parts of the world. The high content of α-linolenic acid in the cultivars of P. vulgaris could very likely play a beneficial role in reducing the risk of coronary heart disease among the large populations consuming them in the southern African region.     

Effects of Geographical Origin on the Conjugated Linolenic Acid of <Emphasis Type="Italic">Trichosanthes kirilowii</Emphasis> Maxim Seed Oil

Trichosanthes kirilowii Maxim (T. kirilowii) seeds from four geographical locations (Changxing, Quzhou, Yuexi, Dongzhi) contained 26.15–49.41% oil and 28.68–37.90% protein. The seed oil was distinguished by the conjugated linolenic acids, punicic acid (PA) and α-eleostearic acid (α-ESA). The main fatty acids in T. kirilowii seed oils were ranked in the following order: punicic acid (33.09–39.15%), linolenic acid (33.77–38.66%), oleic acid (15.15–24.88%), palmitic acid (2.36–4.86%). PA was the main isomer of CLNA (33.09–39.15%). No significant differences were found either in PA content or in α-ESA content of T. kirilowii seed from these geographical locations. Little difference was observed in the quantitative composition of the lipid contents of seeds from different geographical locations. The α-tocopherol content of T. kirilowii seed ranged from 6.34 to 31.74 mg/100 g, with the highest levels in Changxing seeds. The present results showed that T. kirilowii seeds were especially rich in PA, and their contents were not influenced by the geographical locations. Variation in some proximate compositions by geographical locations may be caused by ecological conditions, temperature, climate condition, technical and cultural conditions.     

A Comparative Study of the Properties of Six Sudanese Cucurbit Seeds and Seed Oils

The proximate analysis of seeds and physicochemical properties of oils extracted from six Sudanese cucurbit seeds Cucumis mello var. agrestis, Cucumis melo var. flexuosus, Cucumis sativus, Citrullus lanatus var. colocynthoides, Cucumis prophetarum, and Luffa echinata were examined by established methods. For each variety, the proximate analysis showed ranges for moisture, protein, and carbohydrates as 3.70–6.87, 14.50–17.50, and 15.62–28.89% on a dry matter basis, respectively. The oils were extracted by Soxhlet using petroleum ether, with yields that ranged from 10.9 to 27.10% (wt/wt). The obtained extracted oils were subjected to phyiscochemical, fatty acid, and tocopherol analysis. The physicochemical characterization of the oil revealed that the refractive indices and relative densities of the oils fell within the narrow ranges of 1.334–1.442 and 0.874–0.920 g/cm³, respectively. Unsaponifiable matters ranged between 0.8 and 1.2 mg KOH/g, whilst peroxide values (PV) ranged from 2.3 to 4.1 meq/kg. The ranges of the values for free fatty acid (FFA %) were 1.2–4.0%. The predominant fatty acids were 16:0, 18:0, 18:1, and 18:2 with ranges of 8.9–14.2, 6.0–9.4, 14.6–32.1, and 43.6–65.5%, respectively. γ-Tocopherol was the predominant tocopherol in all samples ranging from 0.8 to 43.2% of the total tocopherols, followed by δ-tocopherol and α-tocopherol.     

Composition of seeds of cruciferous oil crops

Several species of the Cruciferae family are presently used as oilseed crops, viz.,Brassica campestris (turnip rape and sarson),B. juncea (brown or yellow mustard),B. napus (rape),Crambe abyssinica (crambe), andSinapis alba (white or yellow mustard). Seed oils of these species are characterized by variable but generally large amounts of erucic acid (22:1) in the triacylglycerols, which make up 95–98% of the total lipids of high quality, viable seeds. In addition to erucic acid, the major fatty acids are oleic (typically 10–25%), linoleic (10–20%), linolenic (7–11%) and eicosenoic (5–10%). However cultivars of rapeseed lacking erucic acid and having about 55–60% oleic, 20–25% linoleic and ca. 10% linolenic acid have been developed. The eicosenoic and erucic acids are located exclusively at the 1 and 3 positions of the triacylglycerol. As a consequence, major triacylglycerol types have carbon numbers 54, 56, 58, 60 and 62. The phospholipids of rapeseed are essentially devoid of erucic acid and have palmitic, oleic and linoleic acids as major fatty acids. Sterols generally amount to about 0.5% of the oil with β-sitosterol, campesterol and brassicasterol as major constituents (about 55%, 25% and 15%, respectively, of the total sterols). A few per cent of the total sterol fractions is cholesterol. The tocopherol content of rapeseed oil is about 800 ppm with α- and γ-tocopherol as major components. Cruciferous seeds contain a fairly large number of storage proteins. Thus approximately 50 components have been detected in alkaline extracts ofBrassica napus, a major portion of which are in the molecular weight range 120–150,000. The protein spectrum ofB. napus (rape) is more complex than that ofB. campestris (turnip rape) since the former species is an allotetraploid withB. oleracea (kale, cabbage, etc.) andB. campestris as parents. Approximately 5% of the fat free seed meal is composed of glucosinolates, which are split upon enzymatic hydrolysis to antinutritional factors: isothiocyanates, oxazolidinethiones and nitriles. The different crucifers discussed have both qualitative and quantitative differences with respect to glucosinolate content. One of nine papers presented at the Symposium, “Cruciferous Oilseeds,” ISF-AOCS World Congress, Chicago, September 1970.     

Characterization of the seed oil and meal from apricot,cherry, nectarine,peach and plum

The oil and meal from apricot, cherry, nectarine, peach and plum seeds were characterized for their physico-chemical properties. The wt% seed/fruit ranged from 2.8–7.6% and the wt% kernel/seed ranged from 6.8–31.6%. Kernel moisture ranged from 38.8–72.4%. The proximate composition of whole seeds on a dry weight basis ranged from 1.3–6.9% protein, 0.6–14.5% fat, 51.0–72.3% fiber, 0.4–1.2% ash, and 18.1–27.9% carbohydrate (by difference). The kernels contained 41.9–49.3% fat, and the resulting meals contained 31.7–38.7% protein. The major fatty acids were oleic (52.9–66.3%) and linoleic (26.8%–35.0%). The major essential amino acids were arginine (21.7–30.5 mmoles/100 g meal) and leucine (16.2–21.6), and the predominant nonessential amino acid was glutamic acid (49.9–68.0). The iodine values ranged from 105 to 113, hydroxyl value from 5.5 to 7.0 and the unsaponifiables from 0.56–0.80%. The mineral composition (Cu, Fe, Ca, Mg, Zn, P) was also determined on the meals.     

The fatty acid composition of the oil of the winged bean (Psophocarpus tetragonolobus L.) seeds

The seeds of the winged bean,Psophocarpus tetragonolobus L. were found to be rich in oil. The oil was examined for its iodine value, saponification value and fatty acid composition by gas liquid chromatography. The value (area percent) for fatty acids as methyl esters were: 14∶0 (0.2%); 16∶0 (9.1%); 16∶1 (0.4%); 18∶0 (5.4%); 18∶1 (41.0%); 18∶2 (29.5%); 18∶3 (1.9%); 20∶0 (2.0%); 20∶1 and 18∶4 together (2.2%); 22∶0 (7.3%) and 24∶0 (1.0%). The iodine value (Wij solution) was 91. The oil contains an appreciable amount of unsaturated fatty acids, especially linoleic 18∶2 (29.5%). The predominant saturated fatty acid is palmitic 16∶0 (9.1%).     

Comprehensive treatment of secondary dairy stock in polyamide materials

Studies showed that industrial PA membranes can be used for comprehensive treatment of whey containing substances of value to the food industry and allow separating 80% of the protein components in it. PA membranes have ion-exchange properties that allow separating from 20 to 40% of salt cations and anions from the whey and using them in production of food products. __________ Translated from Khimicheskie Volokna, No. 1, pp. 43–45, January–February, 2008.     

Characterization and Compositional Studies of Oil from Seeds of Desi Chickpea (Cicer arietinum L.) Cultivars Grown in Pakistan

The physiochemical properties and fatty acid (FA) composition of oil from seeds of four desi chickpea cultivars, grown in Pakistan, were investigated. The oil content was relatively low (5.88–6.87%). The physiochemical parameters determined included refractive indices (RI) at 40 °C (1.48–1.49), relative density (0.95–0.96), iodine value (IV) (111.87–113.69), acid value (AV) (2.55–2.73 mg KOH/g), saponification value (SV) (183.98–185.64 mg KOH/g), unsaponifiable matter (UM) (2.99–3.71%), peroxide value (PV) (3.97–6.37 mequiv/Kg), p-anisidine value (p-AV) (5.39–8.74), and oxidation value (OV) (13.67–22.34). Linoleic acid and oleic acid were the dominant FAs. Results from most of the parameters revealed significant (P < 0.05) differences among the cultivars. The findings reveal Desi chickpea (Cicer arietinum L.), indigenous to Pakistan, to be a potentially valuable legume crop with comparable nutritional quality oil.     

Year-round high arachidonic acid levels in herbivorous rabbit fish Siganus fuscescens tissues

To identify a stable resource of 20∶4 n−6 (arachidonic acid, AA) in marine fish tissues, the lipid profiles of Siganus fuscescens organs (muscle, liver, and other viscera) and stomach contents were examined throughout the year. Crude total lipid (TL) contents in respective organs showed seasonal variations and were high in winter and low in summer. The main FA in TL were 16∶0, 18∶0, 16∶1n−7, 18∶1n−9, AA, and 22∶6n−3 (DHA). These FA were those generally observed in marine fish lipids, except for comparatively high levels of AA. In TL of muscle and liver, AA showed relatively high values during the period from late May to August (muscle, 4.6–13.1%; liver, 4.5–9.1%), compared with other seasons (muscle, 4.3–9.5%; liver, 3.6–8.4%). The AA levels in TL of other viscera and stomach contents fluctuated (other viscera, 2.0–10.7%; stomach contents, 7.6–26.7%). Regardless of the fishing season, each organ contained a higher level of AA in polar lipids (PL) than in neutral lipids. It was concluded that the fish contain comparatively high levels of AA in their TL throughout the year, and they accumulate AA characteristically in their tissue PL, probably from dietary food sources. Moreover, it was suggested that S. fuscescens has potential utility as a natural marine source of nutritional lipids, because the fish contain comparatively high levels of DHA and AA.     

Milk Thistle Seed Oil Constituents from Different Varieties Grown in Iran

In this study, fatty acids, phytosterol classes and tocopherols composition of Milk thistle seeds oil were determined at four varieties grown in Ardebil-Iran. The four varieties consisted of two modified foreign varieties—Budakalaszi (originally from Hungary) and the CN-seed variety (originally from England) and two native varieties, namely Khoreslo and Babak Castle. The oil content of the seeds ranged from 26 to 31%. Among the fatty acids, linoleic acid had the highest percentage (50–54%) followed by oleic acid (23–29%) and palmitic acid (7–8%). This is the first detailed report on the phytosterol classes of milk thistle seeds oil. The 4-Desmethylsterol class was predominant (1,800–2,200 μg/g) followed by 4,4′-dimethylsterols (50–85 μg/g) and 4-monomethylsterols (26–35 μg/g). The α-, β-, γ-, and δ-tocopherols ranged from 187 to 465, 10 to 51, 9 to 12, and 18 to 80 μg/g oil, respectively. Based on the results obtained, the extracted oil from milk thistle seeds are rich in essential fatty acids, sterols and vitamin E and can be an attractive candidate for use in food preparation mixed with other vegetable oils or alone.     

Antioxidant Distributions and Triacylglycerol Molecular Species of Sesame Seeds (Sesamum indicum)

Extracted lipids from sesame (Sesamum indicum) seeds of three varieties were determined by high-performance liquid chromatography (HPLC) for endogenous antioxidants. The molecular species and fatty acid (FA) distribution of triacylglycerol (TAG) isolated from total lipids in sesame seeds were analyzed by a combination of argentation thin-layer chromatography (TLC) and gas chromatography (GC), and were investigated in relation to their antioxidant distribution. γ-Tocopherol was present in highest concentration, and δ-, and α-tocopherols were very small amounts. Sesamin and sesamolin were the main lignan components. A modified argentation-TLC procedure, developed to optimize the separation of the complex mixture of total TAG, provided 12 different groups of TAG, based on both the degree of unsaturation and the total acyl-chain length of FA groups. With a few exceptions, the major TAG components were SM₂ (6.5–6.7%), SMD (19.8–20.7%), M₂D (15.0–26.3%), MD₂ (23.6–35.0%), and D₃ (7.7–10.7%) (where S denotes a saturated FA, M denotes a monoene, D denotes a diene, and T denotes a triene). It seems that the three varieties were highly related to each other based on the FA composition of the TAG as well as the distribution pattern in the different TAG molecular species. These results suggest that there are no essential differences in the oil components among the three varieties.