Effects of dietary peanut oil on serum lipoprotein patterns of rats

Oils prepared from two varieties of peanuts and from a hybrid corn having linoleic acid concentrations substantially different from the respective commercial oils were compared with commercial oils for their effects on serum lipids of weanling female rats. In the first experiment, serum lipid patterns appeared to reflect linoleic acid content of the dietary oil. However, with a longer feeding period in the second experiment, serum lipid patterns were determined by the plant source of the dietary oil rather than its linoleic acid content; all peanut oils differed from both corn oils in their physiological effects. Diets containing triglyceride, hydrocarbon and sterol fractions obtained by liquid chromatography of peanut and corn oils were fed to female rats. The data provide no evidence that the hydrocarbon or sterol fractions of peanut oil are responsible for its unusual atherogenicity when fed as the sole fat source or that similar fractions from corn oil are protective against the effects of peanut oil.     

Composition of corn oil

The composition of commercial corn oil from USA corn is remarkably constant. A total of 103 samples of refined corn oil produced over a period of 2.5 years were analyzed by the alkali isomerization procedure. Nearly 86% of the samples had an iodine value (I.V.) within one unit of the average value, 123.6. Linoleic content on a fatty acid basis, averaged 55.5%; 93% of the values were within two units of this value. All samples contained small amts of linolenic acid. This uniformity undoubtedly results from the system of corn marketing and buying which brings grain from the entire corn belt to the processing plants. A number of corn oils were analyzed by GLC. The average linoleic acid content by this method was ca. 2.5 units higher than that found by the isomerization method. This difference may occur because GLC responds to all C-18 dienes equally while the alkali isomerization method responds only to conjugatable dienes. Possible sources of error in both methods of fatty acid analysis are discussed. Corn oil samples taken over a 16-month period were analyzed by GLC. Although much of our experience has been with the alkali isomerization method, the GLC technique is preferred because it is simpler and yields more information on fatty acid composition. Another important advantage is that determination of the I.V. of the oil serves as a check on GLC results. The I.V. calculated from the GLC results, making allowance for 1.25% unsaponifiables in the case of corn oil, should be within a few units of the Wijs value. Oils derived commercially from corns grown in other countries are generally more saturated than those from USA corn. The I.V. of the samples examined varied from 107–125, the linoleic acid contents from 42–56%. The relationship between I.V. and linoleic acid content established by others from hybrid corns holds fairly well for these samples.     

Variability in fatty acid composition amongArachis genotypes: A potential source of product improvement

Research on peanut (Arachis hypogeae L.) genotypes has shown a high degree of genetic variability in fatty acid composition. The two major oil fatty acids, oleic and linoleic, range between 36–69% and 14–40%, respectively, and together make up 75–85% of total fatty acids. The very long chain (C₂₀–C₂₄) fatty acids make up 4–9%, palmitic acid 7–13%, and stearic acid 2–5% of total fatty acids. Stability of oil samples as measured by length of autoxidation induction period at 60 C shows variable but statistically significant (P<0.01) correlations with levels of linoleic acid; peanut butter samples show similar patterns of stability. Selection for lower levels of linoleic acid in the development of new varieties of peanuts should results in products with significantly improved shelf life. Some genotypes show consistent differences in oil stability patterns that are not related to oil linoleic acid content. Analysis of entries from 16 wildArachis species collections revealed levels of oil linoleic acid higher than those found inA. hypogaea. One species,A. villosulicarpa, contained 49% linoleic acid and 21% very long chain acids. The range in linoleic acid withinA. hypogaea and availability of suitable techniques for measuring selection progress give scope for product improvement through breeding.     

Effects of dietary vitamin E,selenium, and polyunsaturated fats on in vivo lipid peroxidation in the rat as measured by pentane production

Starting at 21 days of age, groups of six rats each were fed a basal Torula yeast diet supplemented with 0,4% L-methionine and varying amounts of vitamin E as dl-alpha tocopherol acetate, selenium as sodium selenite, and with either 10% stripped corn oil, stripped lard, or coconut oil. By 7 wk, pentane production by rats fed a corn oil diet deficient in both vitamin E and selenium was twice that by rats fed 0.1 or 1 mg of selenium per kg of the same basal diet. Blood glutathione peroxidase activity after 7 wk was proportional to the logarithm of dietary selenium. Groups of rats fed the vitamin E- and selenium-deficient diets with lard or coconut oil had one-half the pentane production of rats fed the vitamin E- and selenium-deficient corn oil diets. The plasma level of linoleic plus arachidonic acid was 1.8 times greater on a wt % basis in rats fed corn oil than in rats fed lard or coconut oil as the fat source. Pentane production by rats fed 40 i.u. dl-alpha tocopherol acetate per kg of the selenium-deficient corn oil diet was one-sixth of that by rats fed the same diet without vitamin E; the plasma of the rats fed the vitamin E-supplemented corn oil diet had a level of vitamin E that was about six times greater than that of the rats fed the vitamin E-deficient corn oil diet.     

Comparison of fatty acid content of imported peanuts

Variability in fatty acid compositions of peanuts imported from six different countries into the United States were studied to determine their effect on processing and storage conditions. The oil content ranged from 44.1 to 50.4%. Major fatty acids, palmitic acid (C16:0), oleic acid (C18:l), and linoleic acid (C18:2) ranged from 8.6 to 12.7, 35.9 to 61.1 and 21.7 to 44.2%, respectively. Oleic and lino-leic acids together comprised ca. 78.0–83.0% of the total fatty acids. Highly significant differences (P<.01) in fatty acid compositions were obtained between samples and between locations (countries of origin). Indicators of stability of the peanut samples as measured by the oleic/linoleic acid ratio (O/L) and iodine value (IV) of the extracted peanut oils showed variable but significant differences (P <.05) between locations. Generally, higher O/L ratios corresponding to lower IV indicate better stability and longer shelf-life of the samples.     

Effect of roasting oil composition on the stability of roasted high-oleic peanuts

Off-flavor due to lipid degradation is an important factor in the shelf life of peanut products. The use of recently developed peanuts with high-oleic acid/linoleic acid (O/L) ratio has the potential to significantly extend the shelf life of roasted peanuts. To determine the full potential for shelf-life improvement of oil-roasted high-O/L peanuts, a study was conducted to examine the effects of roasting high-O/L peanuts (O/L=30) in high-O/L (O/L=23.2) or conventional (O/L=1.5) peanut oil. Peanuts were roasted at 177°C to Hunter L values of 49±1. Roasted peanuts were stored at 30°C for 20 wk. Samples were taken at regular intervals to determine PV, oxidative stability index (OSI), moisture content, and water activity. The O/L ratio of high-O/L roasted peanuts was 27.9 vs. 13.6 for the conventional oil-roasted peanuts. After 20 wk of storage, PV of conventional oil-roasted peanuts was 10.8 compared to 5.3 for the high-O/L-roasted peanuts. OSI values were 88.5 and 52.4 immediately after roasting for the high-O/L-roasted vs. conventional oil-roasted peanuts. OSI for both decreased, but differences remained similar throughout the storage period. Shelf life of high-O/L peanuts decreased when roasted in conventional O/L-peanut oil vs. high-O/L peanut oil.     

Quality factors in exported peanuts from agrentina,China and the united states

In three crop years (1986–1988), peanuts exported from Argentina, China and the United States were evaluated for biochemical composition relative to flavor and shelf-life quality potentials and physical size conformity. Relationships were consistent in that oil stability was associated with high tocopherol and oleic/linoleic acid ratio, and with low free fatty acid, peroxide, carbonyl, and copper and iron content. Peanuts from specific origins had recurring component patterns, with highest indications for shelf life and flavor potential in United States samples. Although no single factor or group of factors can be relied on completely as predictors of flavor or quality, these data establish a significant positive relationship between oil quality factors and roasted peanut flavor quality potential. Argentina and United States peanuts were the most consistently sized, and China peanuts generally had the lowest count/weight.     

Characteristics and composition of indian wood apple seed and oil

Indian wood apple seed (Feronia elephantum Correa) constituting 6% (dry weight basis) of the fruit, contains 34% oil and 28% protein. The kernel comprises 62% of the seed. The oil is yellow with an iodine value 131, saponification value 192, unsaponifiable matter 1%. Fatty acid profile of oil by GLC is: palmitic 19.3, stearic 7.3, oleic 27.2, linoleic 19.8 and linolenic 26.4%.     

Distribution of fatty acids in corn oil

Summary The oil content of 392 samples of corn ranged from 1.13% to 13.80%. As the percentage oil in the corn increased, the degree of unsaturation decreased. Iodine values ranged from 88.4 to 147.4, a range in degree of unsaturation greater than any previously reported for corn oils. The percentage of linoleic acid in the oils ranged from 15.7% to 67.6% and varied inversely with oil content (r=−.691). Oleic acid ranged from 16.5% to 75.9% and saturated acids from zero to 21.3%. The iodine value of the oil showed a high degree of correlation with the percentage of linoleic acid (r=−.951) and can be used as a basis for the accurate prediction of linoleic acid content. Contribution from the Departments of Biochemistry and Botany and Plant Pathology, Purdue University Agricultural Experiment Station and the Division of Cereal Crops and Diseases, Bureau of Plant Industry, Soils and Agricultural Engineering, Agricultural Research Administration, U.S.D.A., cooperating. Journal Paper No. 641 of the Purdue University Agricultural Experiment Station, Lafayette, Ind.     

Cyclopropenoid Acid and Fatty Acid Content of Ten Varieties of Hybrid Cotton Seed Oils

The cyclopropenoid (Malvalic acid) fatty acid content of oils from ten varieties of cotton seeds has been determined range (0.7 to 1.3). Iodine values varied from 32.9 to 114.0. The fatty acid composition was in the following range: Myristic, 0.9-3.0; palmitic, 18.3-34.1; stearic, 2.2-4.5; arachidic, 0.8-1.4; behenic, 0.9-1.2; oleic, 9.7-22.1; linoleic, 42.4-52.5. The oil content varied from 22.5% to 24.5%.     

Flavor stability of high-oleic peanuts stored at low humidity

Shelf-life studies were conducted on roasted high-oleic peanuts (HOP; F1250, BC93Q10) and a reference peanut with normal oleic acid content (NOP, Florunner). HOP contained at least 80% oleic acid and 3% linoleic acid, whereas normal-oleic peanuts contained 53% oleic and 27% linoleic acids. Peanuts were dry-roasted to a medium roast (Hunter lab L=50) and stored at 40°C at 18% relative humidity. Samples were removed from storage at different intervals (0, 2, 4, 7, and 10 wk) for sensory evaluation and chemical oxidation measurements. Sensory attributes rated included roasted peanutty flavor, sweetness, crunchiness, and oxidized flavors (cardboardy and painty). The two HOP lines were not significantly different from each other in flavor quality or stability during storage but had better flavor quality and stability than NOP. The latter oxidized faster and developed painty off-flavors to a greater extent than did the HOP lines. Chemical oxidation measurements confirmed higher levels of oxidation in NOP than in the HOP lines. Peroxide values at 10-wk storage were 47 meq/kg oil for NOP and <3 meq/kg oil for the HOP lines. Both HOP lines had greater shelf lives than NOP.     

Variation in Fatty Acid Compositions, Oil Content and Oil Yield in a Germplasm Collection of Sesame (Sesamum indicum L.)

The variation in oil content, oil yield and fatty acid compositions of 103 sesame landraces was investigated. The landraces varied widely in their oil quantity and quality. The oil content varied between 41.3 and 62.7%, the average being 53.3%. The percentage content of linoleic, oleic, palmitic and stearic acids in the seed oil ranged between 40.7–49.3, 29.3–41.4, 8.0–10.3 and 2.1–4.8%, respectively. Linolenic and arachidic acids were the minor constituents of the sesame oil. Linoleic and oleic acids were the major fatty acids of sesame with average values of 45.7 and 37.2%, respectively. The total means of oleic and linoleic acids as unsaturated fatty acids of sesame were about 83% which increases the suitability of the sesame oil for human consumption. The superiority of the collection was observed in oil content. The oil content of a few accessions was above 60%, proving claims that some varieties of sesame can reach up to 63% in oil content. The accessions with the highest oil content were relatively richer in the linoleic acid content while there were some landraces in which linoleic and oleic acid contents were in a proportion of almost 1:1. The results obtained in this study provide useful background information for developing new cultivars with a high oil content and different fatty acid compositions. Several accessions could be used as parental lines in breeding programmes aiming to increase sesame oil quantity and quality.     

Processing and analysis of onionseed (Allium cepa) and its fixed oil

The characteristics of onionseed (Allium cepa) and its fixed oil are reported. The component fatty acids of the oil by GLC are: palmitic, 7.2%; stearic, 1.2%; oleic, 33.5% and linoleic, 58.1%. The oil was refined and bleached to a light color.     

A method for the separation of seed oil steryl esters and free sterols: Application to peanut and corn oils

A method for separating and quantitating seed oil steryl esters and free sterols was developed using a combination of preparative column, thin layer (TLC), and gas liquid chromatography (GLC). Cholesteryl heneicosanoate and cholesterol served as internal standards. The method was applied to corn-oil samples (Mazola, Kroger) obtained from the local market and peanut-oil samples prepared in the laboratory from commercial varieties of peanuts (Florunner, Starr). Concentration (mg/100 g oil; mean ± SD) of steryl esters and free sterols in the 4 oils were: Mazola, 1420±40 and 370±8; Kroger, 950±40 and 320±4; Florunner, 74±0.5 and 150±3; and Starr, 51±0.5 and 130±2. Sitosterol was the major sterol in both the free sterol and steryl ester fractions of all oils and together with campesterol, stigmasterol and Δ⁵-avenasterol made up 90–95% of all sterols. Steryl esters of peanut oil contained higher proportions of linoleic acid and long-chain acids (C₂₀–C₂₄) than did whole oil. Corn-oil steryl esters also contained a higher proportion of linoleic acid than did whole oil. Squalene was the major hydrocarbon of all oils with the remaining hydrocarbon fraction consisting of a mixture of compounds. Presented at the AOCS meeting, Toronto, May 1982.     

Chromatographic analysis of seed oils. II. fatty acid composition of dimorphotheca oil

The fatty acid composition ofDimorphotheca sinuata seed oil was determined by use of column and gas-liquid chromatography (GLC), and UV, IE, and nuclear magnetic resonance (n.m.r.) spectroscopy. The presence of a small amount of epoxy esters was confirmed by n.m.r. spectroscopy in conjunction with GLC and TLC. The presence of ca. 2.5% of 9-keto-trans,trans- 10,12-octadeca-dienoic acid, previously unrecognized as a constituent of dimorphotheca oil, was established. The estimated fatty acid composition of dimorphotheca oil is 66.5% dimorphecolic, 14% linoleic, 10% oleic, 4.5% palmitic and stearic, and 5% miscellaneous acids.     

Comparison of Fatty Acid Profile of Specialty Maize to Normal Maize

Increasing utilization of specialty maize prompted us to evaluate its fatty acid profile. For this purpose maize germplasm, classified as low oil normal maize (group 1), high oil normal maize (group 2), quality protein maize (QPM) (group 3) and sweet corn (group 4) was evaluated for oil, starch, protein and fatty acid composition mainly palmitic, stearic, oleic and linoleic acid. High oil content was observed in sweet corn samples which might be result of shriveled grain texture because of an increased embryo to kernel ratio. Individual fatty acids showed wide differences among different groups. A slightly higher amount of palmitic acid was reported in specialty maize as compared to normal maize. In contrast, stearic acid content was significantly low in high oil normal maize (56 %), QPM (36.2 %) and sweet corn (28.4 %) in comparison to low oil normal maize. Although no significant differences were observed for oleic acid between low oil normal and high oil normal maize, but sweet corn samples showed significantly reduced oleic acid compared to low oil normal maize. However, the most important observation was the higher content of linoleic acid in specialty maize (groups 2, 3 and 4) as compared to low oil normal maize. Further, the ratio of MUFA/PUFA was also discussed. It was concluded that specialty maize possesses a better oil quality in comparison to low oil normal maize.     

Fatty acid composition of spanish peanut oils as influenced by planting location,soil moisture conditions,variety, and season

Nine varieties or strains of Spanish type peanuts were grown in the National Variety Test in Georgia and Oklahoma with and without irrigation for two growing seasons. The oil of sound kernels was analyzed for fatty acid composition. Although no consistent pattern was found, in general, variation in fatty acid composition due to variety was much less in Oklahoma than in Georgia for both the irrigated and nonirrigated peanuts. Also, location effect and soil moisture conditions gave higher percentages of palmitic and oleic with a lower percentage of linoleic in the Georgia samples and in the nonirrigated samples from both locations. Several significant first and second order interactions with the three major fatty acids involving variety, location, and soil moisture conditions were observed. Presented at the AOCS Meeting, New Orleans, May 1973. Journal paper 2707 of the Oklahoma Agricultural Experiment Station. ARS, USDA.     

Oil content and fatty acid composition of peanuts imported into japan

The oil content and fatty acid composition of Virginia, Runner, and Spanish market types of peanuts imported into Japan were determined. The significant differences among the countries of production were shown in stearic, eicosenoic and lignoceric acid contents of Virginia market type and oil content and palmitic, stearic, oleic, linoleic, eicosenoic, behenic and lignoceric acid contents of Spanish market type. The Spanish market type, as compared with the Virginia market type, was significantly higher in palmitic, stearic, linoleic, arachidic and behenic acid contents and lower in oleic, eicosenoic and lignoceric acid contents on the gross samples.     

Analysis and fatty acid composition of tobacco seed oils

Summary THE fatty acid compositions of twelve samples of oil representing a number of different types and varieties of tobacco were determined by the thiocyanometric method. The samples were remarkably uniform in composition, containing on the average 75% linoleic, 15% oleic, and 10% saturated acids. Spectrophotometric determination of the linoleic acid content of two samples of oil gave values 3.0 and 5.4% higher than those by the thiocyanometric method. A more complete investigation of the fatty acid constituents of one sample of flue-cured tobacco seed oil was carried out by analysis of fractions obtained by distillation of the methyl esters and by low-temperature crystallization of the distilled ester fractions. The composition calculated from these analyses agreed well with that determined from analysis directly on the oil. The saturated acids consisted of palmitic and stearic acids, the proportions being about 7 and 3%, respectively, of the total fatty acids. Analysis of this sample of oil showed that it contained 0.043% of tocopherol. From its composition, tobacco seed oil would seem to be particularly suitable for the manufacture of nonyellowing alkyds or for the preparation of technical linoleic acid. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, United States Department of Agriculture.     

Studies in interesterification. II. Acidolysis of some vegetable oils with lauric acid

Acidolysis reactions of cottonseed oil, peanut oil, mahua oil (Madhuca latifolia), and palm oil with lauric acid were investigated with special reference to the influence of catalysts and the relative proportions of oil and lauric acid on the extent and type of fatty acids displaced from an oil. Catalysts such as sulfuric acid, zinc oxide, calcium oxide, magnesium oxide, aluminum oxide, and mercuric sulfate were used. The reaction generally was carried out by heating oil and lauric acid at 150C±2 for 3 hr. The reaction products were separated and then analyzed by UV spectrophotometry and GLC. Sulfuric acid was found to be the best catalyst with 1 part of oil and 1.2 parts of the displacing acid (lauric acid) for displacement of high-molecular-weight fatty acids from an oil by low-molecular-weight fatty acids. The nature of the displacement of fatty acids varied from oil to oil, depending on their compositions. It was further indicated that linoleic acid was displaced preferentially over oleic acid in an amount dependent on its initial content in an oil with a corresponding increase in saturated acids content. A broad similarity in displacement patterns, in general, was noted; the fatty acids above C₁₈ were not displaced as in the case of peanut oil. The results demonstrate the feasibility of introducing lauric acid in the vegetable oils for the production of interesting oils with vastly different physical and chemical properties.