High Linoleic Sunflower Oil Research Articles

Lipid Quality Changes in French Fries, Chicken Croquettes, and Chicken Nuggets Fried with High-Linoleic and High-Oleic Sunflower Oils in Domestic Deep Fryers.

The quality of fried products greatly depends on the changes occurring during frying. The purpose of this work was to study the lipid quality changes taking place in selected frozen foods after domestic deep-frying. Conventional, high-linoleic sunflower oil (HLSO) and high-oleic sunflower oil (HOSO) were used, and the frozen foods selected were French fries, croquettes, and nuggets. The foods were fried in domestic fryers under discontinuous conditions. Analyses included fatty acid composition, sterols, tocopherols, squalene, and lipid alteration levels. In all fried foods, the content of lipids increased after frying, which is consistent with previous findings. However, the lipid exchange between the food and the oil greatly depended on the food characteristics. Specifically, the levels of frying oil in the food lipids were about 90, 40, and 58% for French fries, croquettes, and nuggets, respectively. The main results obtained showed that lipid alteration levels considerably decreased and amounts of sterols and tocopherols significantly increased in French fries' lipids after frying. In both chicken products, croquettes and nuggets, the best quality improvement observed was a significant decrease in cholesterol in food lipids due to the lipid exchange. Overall, frying with HLSO and HOSO improved the quality and nutritional properties of all products tested.

Influence of consumption of high oleic sunflower oil on the biosynthesis of fatty acids in the liver of rats

Background. To determine the effect of consumption of high-oleic sunflower oil on the content and biosynthesis of energy and polyunsaturated (PUFA) fatty acids in rat liver lipids.
 Methods. Rats received a semi-synthetic fat-free diet in which 5 % or 15 % starch was replaced with high oleic sunflower oil. One group of rats received a diet with 5 % regular (high linoleic) sunflower oil. The duration of feeding was 30 days. Liver lipids were divided into three fractions: neutral lipids, phospholipids and free fatty acids, in which the fatty acid composition was determined by gas chromatography. The "activity" of fatty acid synthase, palmitic acid elongase, and stearyl-CoA desaturase (SCD18) was determined by the ratio of fatty acid content.
 Results. It was found that the largest amount (60-80 %) of fatty acids in liver lipids are energy (C16:0 + C16:1 + C18:0 + C18:1). PUFA account for 10-30% of all fatty acids, and they are also found in the liver lipids of rats fed a free-fat diet (FFD). Fatty diets reduce the "activity" of synthase, but increase the "activity" of elongase and desaturase. A diet with high linoleic sunflower oil reduces the content of ω-3 PUFA in lipids, while a diet with high oleic sunflower oil increases it dose-dependently. Fatty diets containing high oleic sunflower oil dose-dependently reduce the "activity" of palmitic acid desaturase (SCD16). Consumption of high linoleic sunflower oil sharply increases the ratio of ω-6/ω-3 PUFA in liver lipids, while diets with high oleic oil reduce it dose-dependently.

Effect of dietary fats on endogenous oleic acid biosynthesis in rat liver

Aim: Determine the effect of dietary fats with different fatty acid composition on the biosynthesis of oleic acid and its metabolic precursors in the liver .
 Methods: High linoleic sunflower oil (HLSO), high oleic sunflower oil (HOSO) and palm oil (PO) were used. Rats were fed a semi-synthetic fat-free diet (FFD) and fat diets containing 5 % of the above oils (instead of starch) for 30 days. Liver lipids were divided into 3 fractions: neutral lipids (NL), phospholipids (PL) and free fatty acids (FFA). The fatty acid composition of the fractions was determined by gas chromatography. The “activity” of fatty acid synthase was determined from the total content of the products of this reaction (C16:0 and C16:1). The “activity” of palmitic acid elongase was determined by the ratio С18:0/С16:0, as well as by the formula (С18:0+С18:1)/(С16:0–С16:1). The “activity” of stearic acid desaturase (SCD1) was determined by the ratio C16:1/C16:0 (SCD16) and by the ratio C18:1/C18:0 (SCD18).
 Results: In rats treated with fat diets, the content of palmitic and oleic acids is reduced only in the NL fraction, and to the greatest extent when consuming the diet with HLSO. The “activity” of palmitic acid elongase increases significantly with the consumption of a diet with HLSO. SCD16 desaturase “activity” decreases with fat diet, while SCD18 desaturase “activity” increases. The level of SCD18 is significantly higher than the level of SCD16. Consumption of HLSO reduces the content of ω-3 PUFA in rat liver lipids, while the intake of HOSO increases it.
 Conclusions: HLSO diet reduces the endogenous biosynthesis of oleic and palmitic acids, as determined by the analysis of the rat liver NL fraction. A fat diet reduces SCD16 “activity” but increases SCD18 “activity”, especially when fed a diet with HOSO. The diet with HLSO reduces the content of ω-3 PUFA in liver lipids.

The effect of dietary fat supplements on the activity of palmitic and stearic acid desaturases based on the results of a study of the fatty acid composition of neutral lipids in blood serum and liver of rats receiving a fat-free diet

Background. Desaturase enzymes are involved in the formation of monoenoic acids from saturated fatty acids. One such enzyme is stearyl-CoA-desaturase (SCD1), which converts stearic acid to oleic acid. The aim of this work was to determine the effect of edible fats with different fatty acid compositions on SCD1 activity.
 Methods. High linoleic sunflower oil (HLSO), high oleic sunflower oil (HOSO) and palm oil (PO) were used. The rats were fed for 30 days with a semi-synthetic diet that did not contain any fats (FFD) and fat diets containing 5 % of each of the above oils. In animals, lipids were extracted from serum and liver and divided into 3 fractions: neutral lipids (NL), phospholipids (PL), and free fatty acids (FFA).
 The fatty acid composition of each fraction was determined by gas chromatography. The SCD18 activity was determined by the C18:1 n-9/C18:0 ‒ ratio, and the SCD16 activity was determined by the C16:1 n-7/C16:0 ratio.
 Results. A higher activity of SCD16 and SCD18 was found in the NL fraction, and the activity of SCD18 significantly exceeds that of SCD16. A decrease in the content of C16:0, C16:1 and C18:0 in the NL fraction of the liver and blood serum was shown. The activity of SCD16 in blood serum and liver decreases in rats fed fat diets­, while the activity of SCD18 does not decrease, and even increases with the consumption of HOSO.­
 Conclusions. To determine the SCD1 activity, it is advisable to use the C18:1/C18:0 ratio in terms of the level of fatty acids in the NL fraction. Fatty diet inhibits SCD16 activity, and consumption of HOSO increases SCD18 activity.

Quantitative determination of major oxidation products in edible oils by direct NP-HPLC-DAD analysis

The objective of the present study was to explore the possibilities of the direct analysis of vegetable oils by normal-phase HPLC-DAD to evaluate the amounts of the main oxidation products of triacylglycerols containing linoleate, i.e. hydroperoxy-, keto- and hydroxy-dienes. A follow-up of oxidation at 40 °C of trilinolein, used as a simplified model lipid system, high-linoleic sunflower oil and high-oleic sunflower oil was performed to evaluate samples with different fatty acid compositions and different oxidation levels. The results showed that the HPLC-DAD method proposed allows for determining the concentrations of mono-hydroperoxydienes in edible oils without applying any isolation or derivatization step. The method was found to be direct, sensitive (LOQ 0.06 mmol/kg oil), precise (CV ≤ 5%) and also accurate, with 99% of analyte recovery. It also enabled the estimation of the minor amounts of ketodienes, but not those of hydroxydienes, which presented wide chromatographic bands and coeluted with a number of different minor oxidation compounds.

Response Surface Optimization of a Solvent Free Production of <i>cis</i>-9, <i>trans</i>-11 and <i>trans</i>-10, <i>cis</i>-12 Isomers of Conjugated Linoleic Acid Using High Linoleic Sunflower Oil

The most dominant and beneficial conjugated linoleic acids isomers (CLAs) with miscellaneous biological tasks are 9c11t-C18:2 and 10t12c-C18:2. The problem with most of the commercial CLA produced by non-optimized conventional approaches is the heterogeneity of their isomers and undesirable toxic by-products. In this study, optimization of the isomerization of the fatty acid methyl esters of the high linoleic sunflower oil was investigated through response surface methodology (RSM). The reaction temperature, the concentration of PEG400 and NaOCH3 had positive influence on the total conjugated linoleic acid methyl esters (CLAME) production as response. However, the effect of the polyethylene glycol 400 (PEG400) concentration was more significant on response than those of other factors (p i.e., based on the mass percentage of total fatty acid methyl esters mixture) was at 5% w/w NaOCH3, 1.06% w/w PEG400 and temperature of 140°C.

Antioxidants in frying: Analysis and evaluation of efficacy

The action of antioxidants is well known under room temperature conditions during storage or at the moderate temperatures of the accelerated tests used to measure the oil stability. However, efficacy of antioxidants under frying conditions is far more difficult to be evaluated and defined because availability of air is lower and variable, and both oxidation and thermal reactions are simultaneously involved. This review is focused on the analysis and evaluation of efficacy of antioxidants in frying. Specific aspects of the action of natural and synthetic antioxidants at high temperature are discussed, and the most important methods used for the analysis of antioxidants and their efficacy are described.Addition of dimethylpolysiloxane (DMPS) was highly protective during discontinuous frying. Figure shows formation of polar compounds in high‐linoleic sunflower oil (HLSO) and high‐oleic sunflower oil (HOSO) with and without DMPS during discontinuous frying of potatoes at 180°C. Oil degradation was remarkedly decreased by DMPS addition since it is specifically active during the period in which the oil is not protected from the penetration of oxygen by the steam water from the fried food.

Healthy blends of high linoleic sunflower oil with selected cold pressed oils: Functionality, stability and antioxidative characteristics

The consumption of health-promoting products such as cold pressed oils may improve human health and prevent certain diseases. Blends (10% and 20%, w/w) of cold pressed oils including black cumin oil (BC), cumin oil (Cum), coriander oil (Cor) and clove oil (Clo) with high linoleic sunflower oil (SF) were formulated. Oxidative stability (OS) and radical scavenging activity (RSA) of SF and blends stored under oxidative conditions (60°C) for 8 days were studied. By increasing the proportion of cold pressed oils in SF, linoleic acid level decreased, while tocols level increased. Progression of oxidation was followed by measuring peroxide value (PV), p-anisidine value (Av), conjugated dienes (CD) and conjugated trienes (CT). Inverse relationships were noted between PV as well as Av and OS at termination of storage. Levels of CD and CT in SF and blends increased with increase in time. Cold pressed oil blends gave about 70% inhibition of DPPH radicals. Oxidative stabilities of oil blends were better than SF, most likely as a consequence of changes in fatty acids and tocols’ profile, and minor bioactive lipids found in cold pressed oils.

Evaporative light scattering detector in normal-phase high-performance liquid chromatography determination of FAME oxidation products

The use of an ELS detector in NP-HPLC for quantitative analysis of oxidation products in FAME obtained from oils is evaluated in this study. The results obtained have shown that the ELS detector enables the quantitative determination of the hydroperoxides of oleic and linoleic acid methyl esters as a whole, and connected in series with a UV detector makes it possible to determine both groups of compounds by difference, providing useful complementary information. The limits of detection (LOD) and quantification (LOQ) found for hydroperoxides were respectively 2.5 and 5.7μgmL−1 and precision of quantitation expressed as coefficient of variation was lower than 10%. Due to a low sensitivity the ELS detector shows limitations to determine the low contents of secondary oxidation products in the direct analysis of FAME oxidized at low or moderate temperature. Analysis of FAME samples obtained either from high linoleic sunflower oil (HLSO) or high oleic sunflower oil (HOSO) and oxidized at 80°C showed that only ketodienes formed from methyl linoleate can be determined in samples with relatively high oxidation, being the LOD and LOQ 0.2 and 0.4mg/g FAME, respectively, at the analytical conditions applied. The ELS detector also enabled the determination of methyl cis-9,10-epoxystearate and methyl trans-9,10-epoxystearate, which were resolved at the chromatographic conditions applied. Results showed that these compounds, which are formed from methyl oleate, were not detected in the high-linoleic sample, but occurred at non-negligible levels in the oxidized FAME obtained from HOSO.

Green tea extract as food antioxidant. Synergism and antagonism with α-tocopherol in vegetable oils and their colloidal systems

The antioxidant effects of α-tocopherol (TOH) in combination with green tea extract (GTE), the green tea polyphenol (−)-epicatechin (EC) or the isomeric (+)-catechin (C), were investigated using different lipid systems based on high linoleic sunflower oil: bulk oil, o/w-emulsion and a phosphatidylcholine-based liposome system. Both polyphenols as well as TOH were efficient antioxidants in all systems when used alone, as detected by the formation of free radicals and conjugated dienes and by oxygen consumption. Strong synergistic effect was found for the combination of TOH and GTE in a methyl linoleate o/w-emulsion and in the pure bulk oil, while only an additive effect was observed in a liposome system. The synergism was already evident for the tendency for radical formation in the bulk oil as detected by electron spin resonance (ESR) spectroscopy. On the contrary, combinations of TOH with either EC or C showed clear synergistic effects in both heterogeneous systems, but antagonistic or additive effects in bulk oil. GTE may accordingly be used to protect both vegetable oils and their emulsions against oxidation through enhancement of the activity of their endogenous antioxidants, while GTE is less efficient in the protection of phospholipids as in liposomes.

IMPROVING THE STABILITY AND RADICAL-SCAVENGING ACTIVITY OF SUNFLOWER OIL UPON BLENDING WITH BLACK CUMIN (NIGELLA SATIVA) AND CORIANDER (CORIANDRUM SATIVUM) SEED OILS

Blends (10 and 20%, w/w) of black cumin oil (BCO) and coriander oil (CO) with sunflower oil (SFO) were formulated. Oxidative stability (OS) and radical-scavenging activity of SFO and blends stored under oxidative conditions (60C) for 15 days were studied. By increasing the proportion of BCO and CO in SFO, linoleic acid content decreased, while oleic acid content increased. Progression of oxidation was followed by measuring peroxide value (PV), conjugated dienes (CDs) and conjugated trienes (CTs). Inverse relationships were noted between PV and OS at termination of storage. Levels of CDs and CTs in SFO and blends increased with an increase in time. SFO : BCO and SFO : CO blends gave 8–18 and 22–32% inhibition of DPPH• radicals, respectively. OS of oil blends was better than SFO, most likely as a consequence of changes in fatty acids' and tocopherols' profile, and minor bioactive lipids found in CO and BCO. PRACTICAL APPLICATIONS Blending of vegetable oil has emerged as an economical way of modifying the physicochemical characteristics of vegetable oils besides enhancement in oxidative stability. Among new sources of vegetable oils, black cumin seed oil (BCO) and coriander seed oil (CO) are of interest and may play a major role in human nutrition and health. At different concentrations of BCO and CO, oxidative stability of high-linoleic sunflower oil (SFO) was enhanced. Furthermore, blends enriched with BCO and CO had a strong antiradical action. The optimal levels of BCO and CO enrichment will depend on the actual application. It is anticipated that commercial exploitation of SFO : CO and SFO : BCO blends will soon be realized.

Quantitation of Hydroperoxy‐, Keto‐ and Hydroxy‐Dienes During Oxidation of FAMEs from High‐Linoleic and High‐Oleic Sunflower Oils

AbstractThe objective of this work was to study the quantitative formation of hydroperoxydienes, ketodienes and hydroxydienes during autoxidation at 40 °C of fatty acid methyl esters derived from two sunflower oils with different degree of unsaturation, high‐linoleic sunflower oil and high‐oleic sunflower oil. The analysis of the oxidation compounds was carried out by NP‐HPLC–UV and results were compared to the specific extinction at 232 nm (K232) and the peroxide value (PV). Analysis of FAME polymers by HPSEC was also performed to discard samples of advanced oxidation. Results showed that the contents of hydroperoxydienes with respect to the PV were higher for the high linoleic (HL) sample. At the end of the period of slow polymerization (ΔPol ≤ 1 wt%), the content of hydroperoxydienes was found to be 86.0 and 30.7 μg/mg for the HL and high oleic (HO) samples, respectively. Throughout this period, hydroperoxydienes constituted around 90 and 50 wt% of the total hydroperoxides in the HL and HO samples, respectively, suggesting that a significant oxidation of oleic acid also occurred in both samples. The contents of ketodienes and hydroxydienes as a whole constituted 2–3 wt% of the diene compounds analyzed at the end of the period of slow polymerization. Higher contents of ketodienes than of hydroxydienes were found throughout the oxidation time, and the ratio between the contents of ketodienes and hydroxydienes increased with a factor that changed from 1 to 2 throughout the period of slow polymerization.

Quantitative determination of epoxy acids, keto acids and hydroxy acids formed in fats and oils at frying temperatures

A method based on derivatization to fatty acid methyl esters and GC is proposed for the quantitative analysis of hydroxy acids, keto acids and epoxy acids in fats and oils. Isolation of the analytes by solid-phase extraction is proposed to prevent analytical interferences caused by non-altered fatty acids naturally occurring in oils. In addition, hydrogenation is required before the GC analysis to improve repeatability. The analytical method was applied to thermoxidized samples of high linoleic sunflower oil, high oleic sunflower oil and high palmitic sunflower oil. Results showed total levels of these compounds in the order of mg/g of oil in samples with contents of polar compounds ranging from 6.7 to 25.7%. The compounds analyzed constituted major fractions of the oxidized fatty acids.

Decreased aortic early atherosclerosis and associated risk factors in hypercholesterolemic hamsters fed a high- or mid-oleic acid oil compared to a high-linoleic acid oil

Currently, diets higher in polyunsaturated fat are believed to lower blood cholesterol concentrations, and thus reduce atherosclerosis, greater than diets containing high amounts of saturated or possibly even monounsaturated fat. The present study was designed to investigate the effect of diets containing mid- or high-linoleic oil versus the typical high-linoleic sunflower oil on LDL oxidation and the development of early atherosclerosis in a hypercholesterolemic hamster model. Animals were fed a hypercholesterolemic diet containing 10% mid-oleic sunflower oil, high-oleic olive oil, or high-linoleic sunflower oil (wt/wt) plus 0.4% cholesterol (wt/wt) for 10 weeks. After 10 weeks of dietary treatment, only the animals fed the mid-oleic sunflower oil had significant reductions in plasma LDL-C levels (−17%) compared to the high-linoleic sunflower oil group. The high-oleic olive oil–fed hamsters had significantly higher plasma triglyceride levels (+41%) compared to the high-linoleic sunflower oil–fed hamsters. The tocopherol levels in plasma LDL were significantly higher in hamsters fed the mid-oleic sunflower oil (+77%) compared to hamsters fed either the high-linoleic sunflower or high-oleic olive oil. Measurements of LDL oxidation parameters, indicated that hamsters fed the mid-oleic sunflower oil and high-oleic olive oil diets had significantly longer lag phase (+66% and +145%, respectively) and significantly lower propagation rates (−26% and −44%, respectively) and conjugated dienes formed (−17% and −25%, respectively) compared to the hamsters fed the high-linoleic sunflower oil. Relative to the high-linoleic sunflower oil, aortic cholesterol ester was reduced by −14% and −34% in the mid-oleic sunflower oil and high-oleic olive oil groups, respectively, with the latter reaching statistical significance. Although there were no significant associations between plasma lipids and lipoprotein cholesterol with aortic total cholesterol and cholesterol esters for any of the groups, the lag phase of conjugated diene formation was inversely associated with both aortic total and esterified cholesterol in the high-oleic olive oil-fed hamsters ( r = −0.69, P < 0.05). The present study suggests that mid-oleic sunflower oil reduces risk factors such as lipoprotein cholesterol and oxidative stress associated with early atherosclerosis greater than the typical high-linoleic sunflower oil in hypercholesterolemic hamsters. The high-oleic olive oil not only significantly reduced oxidative stress but also reduced aortic cholesterol ester, a hallmark of early aortic atherosclerosis greater than the typical high-linoleic sunflower oil.

Effect of Fat Source on Duodenal Flow of Trans-C18:1 Fatty Acids and Milk Fat Production in Dairy Cows1,2

The objective of the study was to determine the effects of dietary fat source on duodenal flow, apparent absorption, and milk fat incorporation of trans-C18:1 fatty acids. Four ruminally and duodenally cannulated multiparous Holsteins cows in mid to late lactation were fed a basal diet containing 36% corn silage, 24% alfalfa haylage, and 40% concentrate (dry matter basis). Diets contained 0% supplemental fat (control diet), 3.7% high oleic sunflower oil, 3.7% high linoleic sunflower oil, or 3.7% partially hydrogenated vegetable shortening; treatments were administered in a 4×4 Latin square design with 3-wk experimental periods. The flow of trans-C18:1 to the duodenum was higher for cows fed diets supplemented with fat than for cows fed the control diet (283 vs. 64 g/d). Incomplete biohydrogenation accounted for the increased flow of trans-C18:1 to the duodenum in cows fed diets containing high oleic and high linoleic sunflower oil. Increased flow of trans-C18:1 in cows fed the diet containing partially hydrogenated vegetable shortening most likely originated from the trans-C18:1 in the diet. Milk fat percentages were 3.48, 3.07, 3.18, and 3.38% for cows fed the control diet and diets containing high oleic sunflower oil, high linoleic sunflower oil, and vegetable shortening, respectively. Milk trans-C18:1 increased from 2.9 to 11.2% of the total fatty acids for cows fed the control diet and the diets supplemented with fat, respectively. Milk trans-C18:1 were equal across all diets supplemented with fat. Ruminal and total tract digestion of organic matter, neutral detergent fiber, and N did not change with fat supplementation. Results showed that trans-C18:1 is increased in the milk of cows with reduced milk fat; however, excessive amounts of trans-C18:1 in milk do not necessarily correspond directly to milk fat depression.