Applications of sunflower oil in food manufacture

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In book: Sunflowers: Cultivation, Nutrition, and Biodiesel Uses, Chapter: Applications of sunflower oil in food manufacture, Publisher: Nova Science Publishers, Editors: Victor C. Hughes, pp.135-152
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Abstract
Greater than 90 % of commercial oils and fats used for human consumption are plant-derived vegetable oils. The predominant vegetable oils in commerce can be divided into three types based on carbon chain length- lauric, palmitic and oleic oils. Oleic oils predominantly contain 18-carbon fatty acids, stearic, oleic, linoleic and linolenic acids. The soybean, cottonseed, canola, corn, peanut and sunflower oils belong in this category. Sunflower production has increased during the last 25 years mainly because of the high content of linoleic acid that is considered nutritionally positive (essential fatty acid). Commercially available sunflower varieties contain from 39 to 49% oil in the seed. Sunflower oil is generally considered a premium oil because of its light color, high level of unsaturated fatty acids and lack of linolenic acid, bland flavor and high smoke points. The primary use is as a salad and cooking oil or in margarine. In the USA, sunflower oils account for 8% or less of these markets, but in many sunflower-producing countries, sunflower is the preferred and the most commonly used oil. The fatty acid composition of sunflower oil is determined by plant variety and genetics. In a given variety the fatty acid composition changes a little, due to geography and environmental factors. The traditional sunflower oil has a fatty acid composition given in average weight percent as follows: 7 % of C16:0, 5% of C18:0, 19% of oleic, 68% of linoleic, and 1% of C18:3. Relatively recent developments in biotechnology and plant breeding make it possible to develop new genetic varieties, which yield oils with different fatty acid composition than traditional oils. Species of sunflower that possess oil rich in oleic acid exist since 1985. These types contain > 80% oleic acid. High oleic sunflower has higher oxidated stability than conventional oil. It has expanded the application of sunflower oils for frying purposes, tends to enhance shelf life of snacks, and could be used as an ingredient of infant formulas requiring stability. More recently, in 2006, new types of sunflower with such an amount of saturated fatty acids that hardening is no longer necessary or that may be fractionated to obtain a stearin fraction were developed by plant breeding. These oils contain more stearic acid in a high-oleic background, 21% stearic and 62% oleic contents, or less stearic acid, 13% stearic acid content in high-oleic background. This variety will found many applications in food products, such as spreads, sauces, ice-cream, soups, bakery products, and confectionery products.

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  • A method is proposed to assess deterioration of frying fats by measuring polar and nonpolar components separated on a silica gel column. Means for polar components measured in duplicate samples by 19 collaborators ranged from 8.0 ± 0.34 to 25.8 ± 0.90%. Coefficients of variation ranged from 3.5 to 4.9%. The method has been adopted as official first action.
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    Full-text available
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  • Article
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  • Article
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  • Article
    The fatty acid and triacylglycerol composition of a vegetable oil determine its physical, chemical and nutritional properties. The applications of a specific oil depend mainly on its fatty acid composition and the way in which fatty acids are arranged in the glycerol backbone. Minor components, e. g. tocopherols, also modify oil properties such as thermo-oxidative resistance. Sunflower seed commodity oils predominantly contain linoleic and oleic fatty acids with lower content of palmitic and stearic acids. High-oleic sunflower oil, which can be considered as a commodity oil, has oleic acid up to around 90%. Additionally, new sunflower varieties with different fatty acids and tocopherols compositions have been selected. Due to these modifications sunflower oils possess new properties and are better adapted for direct home consumption, for the food industry, and for non-food applications such as biolubricants and biodiesel production.
  • Article
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  • Article
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    Full-text available
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  • Article
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  • Article
    Full-text available
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  • Article
    Full-text available
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  • Article
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  • Article
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  • Article
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  • Article
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  • Article
    Plantings of sunflower,Heliantbus annuus L., were made 5 times between Feb. 2 and Nov. 15 in Florida so that the effect of planting date on the fatty acid composition of sunflower oil might be assessed. Eleven popular hybrids were planted at Gainesville, FL, on Feb. 2 and 28, April 2, and Aug. 14, and 15 hybrids were planted at Lake Worth, FL, on Nov. 15. Sunflower planted on Nov. 15 would be subjected to freezing temperatures if grown in Gainesville. Yields of sunflower achenes for the four planting dates at Gainesville declined with lateness of planting date. Oleic acid content of the oil (17.6–58.4%) was intermediate for the February plantings, highest for the April planting, and lowest for the late plantings. The linoleic acid content (32.5–71.0%) varied inversely with the oleic acid content. Because sunflower oil is needed for different purposes, such as for salad oil, for deep frying and for making margarines, oil low in linoleic acid (high in oleic acid) as well as oil high in linoleic acid (low in oleic acid) are needed. In Florida, adjusting the planting dates should result in the production of oil of the desired fatty acid composition.
  • Article
    The compositions of positionssn-1,sn-2 andsn-3 of triacylglycerols from “extra-virgin” olive oil (Olea europaea) were determined. The procedure involved preparation of diacyl-rac-glycerols by partial hydrolysis with ethyl magnesium bromide; 1,3-, 1,2- and 2,3-diacyl-sn-glycerols as (S)-(+)-1-(1-naphthyl)ethyl urethanes were isolated by highperformance liquid chromatography (HPLC) on silica, and their fatty acid compositions were determined. The same procedure was also carried out on the five main triacylglycerol fractions of olive oil after separation according to the degree of unsaturation by HPLC in the silver ion mode. Although stereospecific analysis of the intact triacyl-sn-glycerols indicated that the compositions of positionssn-1 andsn-3 were similar, the analyses of the molecular species demonstrated marked asymmetry. The data indicate that the “1-random, 2-random, 3-random” distribution theory is not always applicable to vegetable oils.
  • Article
    Changes in composition were examined in oils extracted from genetically modified sunflower and soybean seeds. Improvements were made to the analytical methods to accomplish these analyses successfully. Triacylglycerols (TAG) were separated on two 300 mm × 3.9 mm 4µ Novapak C18 high-performance liquid chromatography (HPLC) columns and detected with a Varex MKIII evaporative light-scattering detector. Peaks were identified by coelution with known standards or by determining fatty acid composition of eluted TAG by capillary gas chromatography (GC). Stereospecific analysis (fatty acid position) was accomplished by partially hydrolyzing TAG with ethyl magnesium bromide and immediately derivatizing the resulting diacylglycerols (DAG) with (S)-(+)-1-(1-naphthyl)ethyl isocyanate. The derivatized sn-1,2-DAG were completely resolved from the sn-2,3-DAG on two 25 mm × 4.6 mm 3 µ silica HPLC columns. The columns were chilled to −20°C to obtain baseline resolution of collected peaks. The distribution of fatty acids on each position of the glycerol backbone was derived from the fatty acid compositions of the two DAG groups and the unhydrolyzed oil. Results for the sn-2 position were verified by hydrolyzing oils with porcine pancreatic lipase, isolating the resulting sn-2 monoacylglycerols by TLC, and determining the fatty acid compositions by GC. Results demonstrated that alterations in the total fatty acid composition of these seed oils are determined by the concentration of TAG species that contain at least one of the modified acyl groups. As expected, no differences were found in TAG with fatty acid quantities unaffected by the specific mutation. In lieu of direct metabolic or enzymatic assay evidence, the authors’ positional data are nevertheless consistent with TAG biosynthesis in these lines being driven by the mass action of available acyl groups and not by altered specificity of the acyltransferases, the compounds responsible for incorporating fatty acids into TAG.
  • Article
    Full-text available
    Thermoxidative stability was evaluated in triaclyglycerols (TAG) from the oils of the mutant sunflower lines CAS-3, CAS-4, and CAS-8 (with a high percentage of stearic acid), CAS-5 (with a high percentage of palmitic acid), all from standard highlinoleic genetic backgrounds, and the mutant sunflower line CAS-12 (with a high percentage of palmitic acid), from a high-oleic genetic background. These oils contained unusually high contents of TAG molecular species with one or two saturated fatty acids at the sn-1,3 positions. Purified total TAG devoid of tocopherols were subjected to controlled thermoxidative treatment at 180°C. Polymerized TAG were determined at 2-h intervals for 10 h. After this time, total polar compounds, oxidized TAG monomers, TAG dimers, and TAG oligomers were determined. TAG from highly saturated sunflower oils with levels of linoleic acid similar to those found in conventional sunflower oils (40–50%) showed enhanced thermal stability. In these TAG, the amount of polar compounds formed during the thermoxidative treatment was similar to that formed in the high oleic acid line. Excellent results were obtained for the TAG of the CAS-12 oil, which had the highest thermal stability, producing half the amount of polar compounds as the conventional line and less than two-thirds that of the high-oleic line.
  • Article
    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.
  • Article
    Tocopherols are natural antioxidants that increase the stability of fat-containing foods and perform important biological activities. Significant variations (389 to 1873 μg g oil−1) in the total tocopherol concentration of sunflower seed oil have been reported. The main objectives of this work were to determine the influence of intercepted photosynthetically active radiation on tocopherol concentration during seed filling and to establish and validate relationships between tocopherol concentration in oil and other quality variables of the seed. Seven sunflower hybrids were grown under good water and nutritional conditions in two similar experiments carried out in two contrasting environments. Treatments were applied to modify the amount of radiation intercepted per plant during seed filling in order to obtain a range in oil yield per plant and its components. Greater per plant intercepted radiation decreased the tocopherol concentration in oil. Tocopherol concentration decreased when oil weight per seed increased. Tocopherol concentration stabilized for oil weight per seed higher than 23 mg oil seed−1. This exponential relationship accounted for 73% of the variability in tocopherol concentration (507 to 1203 μg g oil−1) despite differences in hull type, locations, hybrids, and radiation treatments. The proposed relationship acceptably predicted independent results. Crop management techniques could lead to seeds with greater concentrations of tocopherols.
  • Article
    A sunflower mutant, CAS-3, with about 25% stearic acid (C18:0) in the seed oil was recently isolated after a chemical-mutagen treatment of RDF-1-532 seeds (8% C18:0). To study the inheritance of the high C18:0 content, CAS-3 was reciprocally crossed to RDF-1-532 and HA-89 (5% C18:0). Significant reciprocal-cross differences were found in one of the two crosses, indicating possible maternal effects. In the CAS-3 and RDF-1-532 crosses, the segregation patterns of the F(1), BC(1), and F(2) populations fitted a one-locus (designated Es1) model with two alleles (Es1, es1) and with partial dominance of low over high C18:0 content. Segregation patterns in the CAS-3 and HA-89 crosses indicated the presence of a second independent locus (designated Es2) with two alleles (Es2, es2), also with partial dominance of low over high C18:0 content. From these results, the proposed genotypes (C18:0 content) of each parent were as follows: CAS-3 (25.0% C18:0) =es1es1es2es2; RDF-1-532 (8.0% C18:0) =Es1Es1es2es2; and HA-89 (4.6% C18:0) =Es1Es1Es2Es2. The relationship between the proposed genotypes and their C18:0 content indicates that the Es1 locus has a greater effect on the C18:0 content than the Es2 locus. Apparently, the mutagenic treatment caused a mutation of Es1 to es1 in RDF-1-532.
  • Article
    The relationships between crude and refined oils are examined by quantitation of minor glyceridic compounds, namely, oxidized triglyceride monomers, dimers and diglycerides, associated with oil quality. Particularly, two groups of compounds, i.e. oxidized triglyceride monomers and diglycerides, are of especial interest as they are indicative of oxidative and hydrolytic alterations, respectively. Olive, sunflower and soybean oils differing in initial quality, as evaluated by classical indices and levels of undesirable minor compounds, were subjected to physical and alkali refining in a laboratory system. In all assays, results indicated that amounts of oxidized triglyceride monomers and diglycerides in refined oils remained close to those found in the starting crude oils. Triglyceride dimers were the only group of compounds showing a significant increase, which was dependent on fatty acid composition and initial quality of crude oils. The main conclusion is that quantitation of minor glyceridic compounds in refined oils not only offers a new possibility for quality evalution but also allows the crude oils to be characterised by the presence of markers of oxidative and hydrolytic alterations.
  • Article
    Lipase-catalyzed interesterification of high oleic sunflower oil (HO) and fully hydrogenated soybean oil (FHSBO) at different weight ratios (55:45, 60:40, 65:35 and 70:30, HO:FHSBO) was carried out in both a batch-type reactor (BA) and a packed-bed reactor (PBR) to produce zero trans shortening. Interesterified products in both PBR and BA consisted of 34–46 g/100 g saturated fatty acids (SFA) (mainly stearic acid) and 54–66 g/100 g unsaturated fatty acid (USFA) (mainly oleic acid). After interesterification the physical characteristics such as melting point and solid fat content (SFC) were changed in each product. The differential scanning calorimetry (DSC) result showed that SFC content in PBR was higher than that in BA at each measured temperature. Decrease in tocopherols was also observed, however, the PBR product contained much higher amounts of tocopherols than BA product.
  • Article
    The oxidative and thermal stabilities of genetically modified high oleic sunflower oil (87% oleic acid) were compared with those of regular sunflower (17% oleic acid), soybean, corn, and peanut oils during storage at 55 °C and simulated deep fat frying at 185 °C. Oxidative stability was evaluated by measuring the oxygen content and volatile compounds in the sample bottle headspace and peroxide value. The coefficient variations (CVs) for volatile compound, headspace oxygen, and peroxide value analyses were 2.02%, 1.41%, and 3.18%, respectively. The oxidative stability of high oleic sunflower oil was greater than those of regular sunflower and soybean oil (P < 0.05) and as good as those of corn and peanut oils (P > 0.05). The thermal stabilities of oils during deep fat frying were evaluated by measuring the infrared absorption at 2.9 μm and conjugated diene content. The CV of conjugated diene content was 1.07%. Infrared and conjugated diene results showed that the high oleic sunflower oil had greater thermal stability than had regular sunflower, soybean, corn, and peanut oils (P < 0.05). The genetically modified high oleic sunflower oil, with 5.5% linoleic acid, had better oxidative and thermal stabilities than had the regular sunflower oil with 71.6% linoleic acid.
  • Article
    The objective of this study is to compare the fatty acid composition of commercially available edible oils derived from certified organic and conventional agricultural methods. A total of 59 certified organic and 53 conventional oils were purchased from retail markets in Sydney, Australia. Organic and conventional products were matched for comparison according to the description of production methods, labelled total fat content, brand name (wherever possible), and country of origin. Total fat was extracted and the fatty acid composition of the oils was determined by gas chromatography. No consistent overall trend of difference in the fatty acid composition was observed between organic and conventional oils. Saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids were all significantly different between types of oil (P < 0.001 in all three), and each had significant interaction between type and production method (P = 0.002, P < 0.001 and P < 0.001, respectively) indicating that organic and conventional oils differed in these components in an inconsistent fashion. Despite this, there were large differences particularly between MUFA and PUFA components in specific pairs of oils, especially in sunflower and mustard seed oils. The absence of an overall difference in the fatty acid composition of organic and conventional oils does not support the tenet that organic foods are of a higher nutritional quality than their conventional counterparts.
  • Article
    A zero-trans fat shortening was prepared by chemical interesterification (CI) of high oleic sunflower oil, fully hydrogenated canola oil, and fully hydrogenated soybean oil (FHSO) in a weight ratio of 70:17:13. The product was crystallized in a votator and tested by baking chewy brownie cookies. The CI process produced a fat with comparable plasticity, solid fat content profile, melting point and morphology as the commercial shortening, and was appropriate for use as a high stability shortening. Interestingly, the CI material was predominantly in the β polymorph, and did not seem to be influenced by the mechanical and cooling treatment. Moreover, small crystallites in the range of <5 μm were observed. Cookies containing 30% FHCO showed the same hardness, but a higher spread ratio than cookies made using a commercial shortening. The results of sensory analysis showed the same acceptability for the two types of cookies.
  • Article
    Full-text available
    To improve sunflower (Helianthus annuus L.) oil quality, the pattern of tocopherol and the effect of brief interval of high temperature on tocopherol accumulation during embryo development were investigated. Total tocopherol content increased linearly from 12 to 33 days after anthesis (DAA) and then remained stable until maturity. γ-Tocopherol content reached a maximum on 33 DAA and then decreased. δ-Tocopherol was not detected until 19 DAA. The effect of brief interval of high temperature (⩾35 °C for seven consecutive days) on tocopherol accumulation was studied. The accelerating effect of high temperature on tocopherol accumulation on a dry weight basis was detected, but the reduction of tocopherol yield occurred from 12 to 19 DAA because the embryo dry weight was reduced significantly. However, the embryos exposed to a temperature of 35 °C from 12 to 19 DAA significantly increased the tocopherol yield per embryo, with no effect on the dry matter weight. These results are useful for evaluating the tocopherol content in sunflower oil and may help recognizing high quality of the oil.
  • Article
    The loss of specific molecular species of triacylglycerols from sunflower, high-oleate sunflower and palm oils has been investigated in commercial frying operations and simulated frying experiments. The non-oxidized triacylglycerols were isolated and molecular species separated by silver ion highperformance liquid chromatography. Linoleate-containing species were lost more rapidly than those containing oleate, as expected. However, all species were liable to oxidation and those containing oleate were lost more rapidly than might have been anticipated. It is suggested that oxidation of linoleate is the probable initiation step, but then the reaction can be propagated readily to all unsaturated species.
  • Article
    A study is made of the evolution of the composition of sunflower oil kept over prolonged periods of time at high temperature (190 degrees C) in a domestic fryer. The technique used is (1)H NMR spectroscopy. The degradation rate of linoleic acyl groups is determined in this process, as well as the proportions of monounsaturated, of saturated plus modified acyl groups and the iodine values. Intermediate oxidation compounds having hydroperoxide groups and conjugated dienic systems were not detected; however, some secondary oxidation compounds such as aldehydes are generated very early, among them, the genotoxic and cytotoxic 4-hydroxy-trans-2-alkenals. Both concentrations of each kind of aldehyde at different heating times and changes in their concentration were also determined. Simultaneously, the level of oil degradation corresponding to a content of 25% of polar compounds measured by Viscofrit test was analyzed in function of the (1)H NMR spectra derived data.
  • Article
    Triacylglycerol oxidation of thermally stressed (6 h at 180 degrees C, simulating deep-frying conditions) edible vegetable oil (sunflower and olive) was studied using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Chromatographic separation of the nonpolar and polar components from the heated oil performed on silica gel prior to MS analysis significantly enhanced the detection of oxidized components. The spectra contained signals that were assigned to triacylglycerols (TAG), diacylglycerols (DAG), triacylglycerol oxidative dimers, oxidized TAG, and TAG fragments arising from the homolytic beta-scission of linoleyl, peroxy, and alkoxy radicals. Enrichment of the polar compounds prevented mass spectrometric ion suppression, thus allowing the detection of minor species originating from thermal oxidation. In addition, this allowed the monitoring of polar compounds in vegetable oils undergoing mild thermal treatment. As such, chromatographic separation coupled with MALDI-TOF MS analysis provided a rapid, sensitive, and specific tool to assess the thermal oxidation of vegetable oils.
  • Article
    The 1,3-random-2-random theory was proposed several years ago to explain the fatty acid distribution in vegetable oil triacylglycerols. However, by demonstrating an asymmetry between positions sn-1 and sn-3 in olive oil, cocoa butter, sunflower oil, etc., a number of studies have shown that this theory does not hold true for some oils and fatty acids. Accordingly, the distribution of fatty acids in sunflower triacylglycerols has been studied, calculating the alpha coefficient of asymmetry in several combinations of standard linoleic, high-oleic, and high-stearic sunflower oils. The results obtained from the oils of these lines and from single seed oil samples indicate that the asymmetry for saturated fatty acids is greater in high-oleic than in standard linoleic backgrounds. Hence, the distribution of the fatty acids within the triacylglycerol molecule appears to depend not only on the fatty acid under study but also on the other fatty acids in the oil. Thus, it is demonstrated for the first time that certain fatty acids can influence the distribution of other fatty acids within triacylglycerols.
  • A compilation has been made of the individual tocopherols in foods based on available literature reports for the period 1965 to 1975. Tocopherol content depends on stage of life cycle, agronomic and genetic factors, season, weather, harvesting methods, processing procedures, storage environment, and time periods of storage. Tocopherols are sensitive to oxygen and oxidative reactions, especially in the presence of catalysts, heat, alkali, and certain radiation. α‐Tocopherol has the highest vitamin E activity for man and animals and is usually the predominant tocopherol in their tissues. Its content varies in plant tissues. A technology currently exists for the addition of the mote stable ester α‐tocopheryl acetate to foods as a nutrient where it has merit and α‐ or γ‐tocopherol as an antioxidant to foods where natural‐type antioxidants are desired.
  • Article
    Deep-fat frying is one of the most commonly used procedures for the preparation and manufacture of foods in the world. During deep-fat frying, oxidative and thermal decompositions may take place with the formation of volatile and nonvolatile decomposition products, some of which in excessive amounts are harmful to human health. A limited survey of frying fats used in commercial operations indicated that some were maintained at good quality and others were overused or abused. The volatile decomposition products produced by corn oil, hydrogenated cotton-seed oil, trilinolein, and triolein, under simulated commercial frying conditions, were collected, fractionated, and identified. A total of 211 compounds were identified. The nonvolatile decomposition products produced by trilinolein, triolein, and tristearin under simulated commercial frying conditions were collected and characterized. After being treated under deep-fat frying conditions at 185 C for 74 hr, trilinolein yielded 26.3% non-urea-adduct-forming esters, triolein yielded 10.8%, and tristearin also yielded 4.2%.
  • Article
    Polyunsaturated fatty acids are thought to lower the serum cholesterol level more effectively than monounsaturated fatty acids. It is unclear whether the difference--if any--is due to a lowering of the level of high-density lipoprotein (HDL) or low-density lipoprotein (LDL) cholesterol. We therefore placed 31 women and 27 men on a mixed natural diet rich in saturated fat (19.3 percent of their daily energy intake from saturated fat, 11.5 percent from monounsaturated fat, and 4.6 percent from polyunsaturated fat) for 17 days. For the next 36 days, they received a mixed diet with the same total fat content, but enriched with olive oil and sunflower oil ("monounsaturated-fat diet": 12.9 percent saturated fat, 15.1 percent monounsaturated fat, and 7.9 percent polyunsaturated fat) or with sunflower oil alone ("polyunsaturated-fat diet": 12.6 percent saturated fat, 10.8 percent monounsaturated fat, and 12.7 percent polyunsaturated fat). The serum LDL cholesterol level decreased by 17.9 percent in those on the monounsaturated-fat diet and by 12.9 percent in those on the polyunsaturated-fat diet (95 percent confidence interval for the difference between the effects of the two unsaturated-fat diets, -9.9 percent to 0.0 percent). In men, the HDL cholesterol level fell slightly but not significantly with both diets. In women, the HDL cholesterol level did not change with either. We conclude that a mixed diet rich in monounsaturated fat was as effective as a diet rich in (n-6)polyunsaturated fat in lowering LDL cholesterol. Both diets lowered the level of HDL cholesterol slightly in men but not in women.
  • Article
    Conjugated dienoic linoleate (CLA), a linoleic acid derivative, has received considerable attention as a chemoprotective agent in the past few years because it has been shown experimentally to inhibit rat mammary tumorigenesis, mouse forestomach neoplasia, and mouse skin carcinogenesis. CLA has several unique structural and functional properties resulting in chemical and physiological effects that are different from those of all-cis, nonconjugated polyunsaturated fatty acids. In turn, these unique qualities appear to modulate cellular processes involved in carcinogenesis. This review will introduce the chemical background of conjugated dienoic linoleate, examine findings describing its chemoprotective qualities, present possible mechanisms of chemoprotection, and correlate the possible significance of dietary CLA modulation to carcinogenesis to humans.
  • Article
    Full-text available
    Dietary fatty acids in the sn-2 position are preferentially absorbed as monoacylglycerols. To determine whether thy also have more important biologic effects, rats were fed for 2 and 4 mo a purified diet containing native palm oil, interesterified palm oil, native lard or interesterified lard. Interesterification that increased or decreased the level of fatty acids in position 2 depending on the fat, resulted in significant corresponding changes in the fecal excretion of saturated fatty acids. Fecal excretion of saturated fatty acids was associated with significant changes in some plsma fatty acids. Interesterification in lard resulted in significantly lower plasma triglycerides, and in palm oil, increased platelet aggregation induced by ADP. Lipemia, platelet aggregation and associated plasma fatty acids (palmitic, heneicosanoic and docosahexaenoic acids) were significantly affected only by dietary fatty acids at the sn-2 position. Even without changes in absorption, only linoleic acid in position 2 was correlated with the plasma concentration of the corresponding longer chain arachidonic acid. These results in rats confirm that the fatty acids (saturated and unsaturated) in position 2 of dietary triglycerides play a crucial role in the metabolism and biologic effects of these fatty acids.