Sunflower Oil Samples Research Articles

Genotoxic and Carcinogenic Risks Associated with the Consumption of Repeatedly Boiled Sunflower Oil

Repeated boiling of vegetable oils at high temperature in cooking and frying is a very common practice and leads to the formation of a class of toxic substances. Among them, polycyclic aromatic hydrocarbons (PAHs) are well-documented for their mutagenic/carcinogenic potential. The objectives of the present study were to evaluate the genotoxic and carcinogenic risks associated with the consumption of repeatedly boiled sunflower oil, which is one of the commonly consumed vegetable oils in southeast Asian countries. The presence of PAHs was analyzed using high-performance liquid chromatography (HPLC) methods in fresh, single-boiled, and repeatedly-boiled sunflower oil (FSO, SBSO, and RBSO) samples. A higher amount of known carcinogenic/mutagenic PAHs in RBSO samples were shown, as compared to FSO and SBSO. Oral administration of RBSO in Wistar rats resulted in significant induction of aberrant cells (p < 0.05) and micronuclei (p < 0.05) incidence in a dose-dependent manner. Oxidative stress analysis also showed a significant decrease in levels of antioxidant enzymes, such as superoxide dismutase and catalase, with a concurrent increase in reactive oxygen species and lipid peroxidation in animals following RBSO consumption, as compared to FSO or SBSO (p < 0.05). Additionally, RBSO administration alone and along with diethylnitrosamine for 12 weeks induced altered hepatic foci, as noticed by the alteration in positive (γ-glutamyl transpeptidase and glutathione-S-transferase) and negative (adenosine-triphosphatase, alkaline phosphatase, and glucose-6-phosphatase) liver biomarkers. A significant decrease in the relative and absolute hepatic weight in RBSO-supplemented rats was also noted (p < 0.05).

Development of a method to determine Ni and Cd in biodiesel by graphite furnace atomic absorption spectrometry

This paper proposes a low cost, simple, fast method for determining Ni and Cd in biodiesel samples by graphite furnace atomic absorption spectrometry (GFAAS). The method was evaluated in biodiesel from different sources. Tungsten was used as a permanent modifier and the samples were prepared in the form of microemulsions, by mixing about 0.5 g of biodiesel with 5 g of surfactant (Triton X-100) in volumetric flasks and completing the volume with HNO 3 1% (v/v). The detection limits obtained for Ni and Cd in microemulsions were ≤0.9 and 0.1 μg L −1, respectively. The relative standard deviation (% R.S.D., n = 12) was ≤8.20% for Ni (washed animal fat sample) and ≤4.71% for Cd (sunflower oil sample). Accuracy was checked based on addition and recovery experiments, which yielded recovery rates varying from 93% to 108% for Ni and from 98% to 116% for Cd. Sample preparation is rapid and easy, and the use of an inorganic standard for calibration makes this sample preparation procedure suitable for routine applications.

Effects of residual phospholipids on surface properties of a soft-refined sunflower oil: Application to stabilization of sauce-types’ emulsions

Vinegar sauces’ type emulsions were prepared from water–alcohol mixture (90:10) and three different sunflower oil samples (Reference oil, SUN1 and SUN3) at 20 wt% with sunflower lecithin as O/W emulsifier. Besides the addition of lecithins at 0–2 wt%, the oil composition varied based on the minor components present in each oil due to the different crushing and refining process. Reference oil sample was nutrient-free while SUN oil contained nutrient component sterols, tocopherols, phosphorus and phenols. Interfacial tension of the different systems was monitored using an automated tensiometer. The vinegar sauces’ type oil-in-water emulsions were prepared by a two-step homogenization procedure (10,000 rpm for 10 min, followed by a passage through an homogenizer at 400 bar pressure), the lipid droplets’ stability against aggregation/coalescence was monitored using integrated light scattering (particle size distribution) and multiple light scattering (creaming) measurements for two-month storage at 4 °C. In the absence of added lecithins, SUN oil sample containing phospholipids presented lower interfacial tension values than the Reference oil. Equilibrium values obtained are ∼4.4 mN m −1 for SUN3, ∼10.5 mN m −1 for SUN1, instead of 13.7 mN m −1 for Reference sample. Addition of phospholipids (lecithin) to the Reference sample led to a similar trend of adsorption kinetics observed in the SUN sample (nutrient rich oil). SUN3 showed the best ability to form elastic film and Reference oil showed lowest ability, which could be attributed to concentration and the composition of phospholipids. In addition, the SUN emulsions (stored at 4 °C and 22 °C) were more stable against creaming and smaller in droplet size with increased concentration of added lecithins.

Static Headspace Sampling and Solid-Phase Microextraction for Assessment of Edible Oils Stability

Static headspace sampling and headspace solid-phase microextraction have been applied for the determination of the low molecular mass aldehydes—markers of edible oil oxidation. Preconcentration and determination conditions for the two procedures were optimized. LODs LOQs and repeatability of a standard mixture were established for all investigated compounds. Both methods of sampling were applied to the analysis of samples of rapeseed and sunflower oils. It appears that solid-phase microextraction is better than headspace sampling for the analysis of volatile oxidation products. Solid-phase microextraction can be conducted at a much lower temperature and has lower LOD values and better repeatability than headspace sampling.

Oxidative stability of olive oil after food processing and comparison with other vegetable oils

The use of olive oil showed an important protection of meat and potatoes when compared with other vegetable oils, with sunflower oil samples being oxidised after 60 min of processing at 180 °C. Olive oil samples were not oxidised, independently of the olive oil quality used. Shelf life was longer for extra-virgin olive oil containing samples and this fact was positively correlated with their higher phenolic content. The radical-scavenging activity of extra-virgin olive oil was higher than for other olive oil samples and was also positively correlated with the phenolic content of the oil. Seed oil antioxidants showed little capacity in delaying the oxidative degradation of seed oils and meat processed with them. However, tocopherol content and the identity of tocopherols present in the oil were shown to have a more important role in the oxidative stability of seed oils than the fatty acid composition. The presence of food showed a protective effect on the oils, with oil samples processed without food showing a higher level of oxidation than the oil samples processed in the presence of food. All polyphenolic components of olive oils decreased in concentration with the thermal treatment and this decrease was dramatic in the presence of food. During processing, two new compounds were found in olive oil samples and their concentration was higher for samples containing a higher initial polyphenolic content. The content in tocopherols was not so dramatically affected by the thermal treatment as was the polyphenolic content. Moreover, a sparing effect of food was, however, observed with the tocopherol content of samples which probably contributes to the better oxidative stability of these samples.

Adulteration detection of argan oil by inductively coupled plasma optical emission spectrometry

Abstract The singularity of the trace element profile of argan oil has been demonstrated by means of inductively coupled plasma optical emission measurement in combination with different chemometric approaches. The ability of multivariate analysis methods; such as hierarchical cluster analysis (HCA), principal component analysis (PCA), classification trees using Chi -squared Automatic Interaction Detector (CHAID) and discriminant analysis (DA) to achieve edible oils classification based on its type or variety from their elemental content have been investigated. The calculations were performed using 16 variables (contents of Na, Mg, Al, K, Ca, Ti, Fe, Co, Ni, Cu, Zn, Cd, Pr, Sm, Er and Bi at μg g −1 level determined by ICP-OES). HCA is able to differentiate sunflower oil samples from the rest, however the discrimination of argan oil from olive, seeds and soya oils based on their different trace element composition is hard to achieve. The PCA analysis shows three different classes in the multidimensional space (PC1-3) representing sunflower, argan and a third group comprising olive, seeds and soya oils. CHAID method allows separating the entire vegetable oil dataset, providing a correct re-substitution rate of 94.12% for argan oil using only the concentration of K. DA performed using the same variables, provides also an acceptable average accuracy results of 93.65%, by the re-substitution method. DA has been successfully applied to the analysis adulterated argan oil by addition of cheaper vegetable oils.

Aflatoxin B1 contamination in sunflower oil collected from sunflower oil refinery situated in Karnataka

In the present study, the aflatoxin B1 contamination at various stages of oil refining and in refined oil were carried out. This was subsequently compared with commercial vegetable oil samples. Among the 23 different sunflower oil samples were tested, 10 of them showed posi-tive results to AFB1 and the remaining 13 showed negative results to AFB1. All the refined oil samples were free from AFB1 contamination.

بررسی مهاجرت ترفتالات از بطری های PET روغن آفتابگردان, تولیدی کارخانه پارس

In Iran, the majority of vegetable oil producers , use PET for packaging their products . Due to high solubility of PET oligomers in the oils , and shelf life of liquid oils , it is expected that some compounds migrate into the oil . This study was carried out to determine the amount of migration of terephtalates from PET bottles into sunflower oil and the effect of temperature and storage time on the degree of migration. 42 samples of liquid sunflower oil packed in one litre PET bottles, from single production bach of pars vegetable oil, were kept at 20˚C and 40˚C. Experiments were carried out on three bottles taken at different periods of time (10, 20, 30, 70, 145 & 202days). According to Castle method , alkaline hydrolysis of all PET oligomers to terephthalic acid followed by its methylation to dimethylterephthalate (DMT) for the measurement of DMT, derivative UV spectrophotometer was used according to Reeves.The results showed that the maximum level of migration of terephthalates at 20 ˚C was 29.43 + 0.93 and at 40˚C was 29.58 + 1.15. Therefore the amount of overall migration obtained in this research is lower than the international permitted level (lower than 60 ppm) and sunflower oil after the final migration can be safely consumed. Migration increased with the passage of time until it reached to its highest level and then stopped (P=0). Migration is faster when the temperature is increased (P=0.014). Therefore, migration is dependant on both temperature and contact time (P=0.001). In this research, linear dependence between migration and square root of time has also been demonstrated (r = 0.96 at 20 ˚C from time zero to 145 days and r = 0.95 at 40˚C from time zero to 70 days). Reproducibility of the method was evaluated by calculating the relative standard deviation which was equal to 3.21% and the detection limit of the method was 0.21 ppm. In conclusion migration of PET oligomers was dependant on time and temperature, until it reaches an equilibrium. Keywords: Plastic bottle, Migration, Sunflower oil, Polyethylene terephthalate (PET), Derivative UV Spectrophotometry , PET oligomers.

Antioxidant Evaluation of Coriander Extract and Ascorbyl Palmitate in Sunflower Oil Under Thermoxidation

AbstractThe objectives of this study were to evaluate isolated and synergistic antioxidant effects of coriander extract and ascorbyl palmitate (AP) in sunflower oil subjected to thermoxidation, and to verify their influence on the oxidative resistance of α‐tocopherol, which occurs naturally in safflower oil. Sunflower oil samples with 1,600 mg/kg coriander extract, 500 mg/kg AP, and a mixture of those two antioxidants were heated to 180 °C for 30 h. Samples were taken at 0, 10, 20 and 30 h and analyzed to evaluate oxidative stability, total polar compounds, and α‐tocopherol content. Results were subjected to variance analyses and Tukey tests at a 5% significance level, in a factorial scheme, to an entirely casual delineation. Coriander extract and AP delayed lipid oxidation and promoted the retention of α‐tocopherol when added separately to sunflower oil and subjected to thermoxidation. The mixture of the antioxidants showed a higher antioxidant effect, thereby demonstrating their synergy under these conditions.

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.

Application of NIR Spectroscopy by Determination of Quality Properties of Vegetable Oils and Their Derivatives

This study shows that near-infrared spectroscopy is a reliable technique to determine the concentration of the key fatty acid (FA) components (oleic, linoleic, linolenic acid), the acid number, the iodine value and the kinematic viscosity at 40 and 100 °C in sunflower and rapeseed oils. To establish the chemometric model, a calibration set of 36 rapeseed oil samples and 47 sunflower oil samples were used and 51 oil samples were used for external validation. All samples were measured on a BRUKER-MPA spectrometer in transmittance mode. The samples were scanned in a wave number range of 12000–4000 cm-1 with a resolution of 2 cm-1. The sample scan time was 32 scans. To develop and optimize the calibration models partial least squares (PLS) method was used with cross validation. The result of the experiment showed that this technique is sufficiently accurate for estimating the FA composition, the acid number, the iodine value and the kinematic viscosity at 40 and 100 °C in sunflower and rapeseed oil. The calibration results had root mean square error of cross validation (RMSECV) for oleic acid, linoleic acid, linolenic acid, acid number, iodine value, viscosity at 40 °C, viscosity at 100 °C of 0.395, 0.451, 0.0932, 0.208, 0.418, 0.12, 0.0237 respectively and determination coefficient (R2) (%) for the same properties of 99.96, 99.97, 99.95, 99.47, 99.88, 99.7, 99.22 respectively.

Quantitative Silver Ion Thin Layer Chromatography of Triacylglycerols from Sunflower Oils Differing in the Level of Linoleic Acid

Eight samples of sunflower oil with different linoleic acid contents (9–63{%}) were subjected to a triacylglycerol (TAG) analysis by silver-ion thin-layer chromatography with densitometric quantification. In spite of this substantial change in the fatty acid composition, the relative content of the component TAG classes in the sum of polyunsaturated triacylglycerols remains constant. Thus, a characteristic fingerprint of sunflower oil TAG has been outlined. It is not affected by the linoleic acid content and might be of use in authenticity and adulteration control of sunflower and olive oils.

Formation of oxygenated α,β-unsaturated aldehydes and other toxic compounds in sunflower oil oxidation at room temperature in closed receptacles

The study of the volatile components presents in the headspace of 27 sunflower oil samples, stored over different periods of time, at room temperature in closed receptacles, in presence of limited amounts of air, has been carried out by solid phase microextraction (SPME) followed by gas chromatography/mass spectrometry (GC/MS). The composition of the headspace of the studied samples is highly varied, ranging from the characteristic of non-oxidized oils to that of oils with a high oxidation level. Among the detected compounds are alkanals, ( E)-2-alkenals, 2,4-alkadienals, ketones, acids, esters, alcohols, as well as aliphatic and aromatic hydrocarbons. In samples having a certain oxidation degree it is worth noting the presence of a significant number of genotoxic and cytotoxic oxygenated α,β−unsaturated aldehydes (OαβUΑs), such as 4-hydroxy-2-nonenal, 4-oxo-2-nonenal or 4,5-epoxy-2-decenal, which have been considered responsible for various degenerative diseases which are widespread nowadays; some of these compounds are described in this manuscript for the first time as coming from edible oil oxidation at room temperature. In addition, it has been found the occurrence of polycyclic aromatic hydrocarbons (PAHs) in concentrations in line with the oxidation level of the sample.

Evidence of the Formation of Light Polycyclic Aromatic Hydrocarbons during the Oxidation of Edible Oils in Closed Containers at Room Temperature

Solid phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) of the headspace composition of two sunflower oil samples was carried out; both samples were taken from the same original oil, stored for a prolonged time (112 months) in closed containers at room temperature under different air/oil volume ratios. Great differences in the headspace compositions of both samples were found due to the different oxidation levels reached. One of the most significant findings is that both contain monocyclic and light polycyclic aromatic hydrocarbons, the proportions of which are in line with the oxidation level of the sample. The determination of polycyclic aromatic compounds in the oil liquid matrix of both oil samples, carried out by means of a classical scheme of isolation, cleanup, separation, and quantification, showed that the concentrations of these compounds in the oil liquid phase also follow the oxidation degree reached by each sample, proving that this oxidation process at room temperature leads to the formation of these compounds.

Improved Extraction Method for the Determination of Iron, Copper, and Nickel in New Varieties of Sunflower Oil by Atomic Absorption Spectroscopy

A simple and fast procedure is proposed for the extraction of iron (Fe), copper (Cu), and nickel (Ni) in 16 varieties of sunflower seed oil samples using an ultrasonic bath. The experimental parameters of the ultrasonic-assisted extraction (UAE) method were optimized to improve the sensitivity and detect the metals at trace levels in minimum time. Conventional wet acid digestion method was used for comparative purposes. The optimum recovery of all 3 metals was obtained by UAE for 7 min, while the separation of aqueous and organic phases after extraction using centrifugation (UAE-2) required 3 min, as compared to the conventional equilibration method (UAE-1) that required 90 min. The respective recoveries of Cu, Fe, and Ni obtained with UAE-2 were in the range of 95.8-97.5, 93.5-98.3, and 95.6-98.2%, respectively, for different varieties of sunflower oil samples. Accuracy was determined by the standard addition method. Under the optimum operating conditions, the limits of detection obtained from the standard addition curves were 21.7, 20.4, and 35.6 ng/mL for Fe, Cu, and Ni, respectively. The fact that all varieties of sunflower oil contain significant amounts of Fe, Cu, and Ni indicates the deterioration of sunflower oil quality immediately after extraction from seeds, which poses a threat to oil quality and human health.

A rapid method for determination of polar compounds in used frying fats and oils

The determination of polar compounds by adsorption chromatography is the most accepted method for the analysis of used frying fats due to its high precision and accuracy. However, this method is expensive and time consuming. In this study, a rapid analytical method to determine polar compounds is proposed. Starting from milligrams of sample dissolved in a solution of hexane containing methyl oleate as internal standard, the nonpolar fraction, which comprises the non-altered triglycerides (TG) and the internal standard, is obtained by solid phase extraction. Then, the non polar fraction is quantitatively analyzed in 15 min by high-performance size-exclusion chromatography (HPSEC) and the polar fraction is determined by difference of weight. Response factors for pure TG and FAME were calculated. Six samples of sunflower oils of different degrees of unsaturation were analyzed in triplicate and the results were compared with those obtained by the gravimetric method based on silica classical column chromatography. Results showed no significant differences between the two methods. In addition, the repeatability of the proposed method was excellent, as the coefficient of variation ranged from 1.5 to 13% depending on the contents of polar compounds.

STABILIZATION OF SUNFLOWER OIL WITH MORINGA OLEIFERA LEAVES UNDER AMBIENT STORAGE

ABSTRACT The effect of Moringa oleifera leaves on the stability of sunflower oil (SFO) was investigated. The samples of M. oleifera leaves were extracted using 80 and 100% methanol, and 80 and 100% acetone, respectively. Preliminary assessment of antioxidant activity of the extracts was carried out by the estimation of total phenolic contents (TPCs), loss of β‐carotene and percent inhibition of peroxidation in linoleic acid. The TPC of different solvent extracts of M. oleifera leaves was 5.32–8.00 g/100 g (dry mass basis). The level of inhibition of peroxidation in the linoleic acid system was 85.00–91.86%. Furthermore, preheated refined, bleached and deodorized (RBD) SFO samples were stabilized with crude extracts at a concentration of 600 ppm and subjected to ambient storage for 2 months. The progression of oxidation was followed by the measurement of peroxide value, conjugated dienes, conjugated trienes, and p‐anisidine values. The overall order of antioxidant efficacy of the extracts of M. oleifera leaves, as determined by various antioxidant assays and oxidation parameters, was as follows: 80% methanolic extract, &gt;100% methanolic extract, &gt;80% acetone extract and &gt;100% acetone extract.

PAHs content in sunflower, soybean and virgin olive oils: Evaluation in commercial samples and during refining process

Polycyclic aromatic hydrocarbons (PAHs) are environmental carcinogenic compounds that may contaminate vegetable oils and their levels can be reduced by refining. In order to understand the influence of the refining steps, the content of 15 PAHs was assessed throughout alkaline refining in soybean, sunflower and olive oil samples. Eight commercial brands of these oils were also analysed. The analytical method involved a liquid–liquid extraction, a solid-phase clean up (C 18 and Florisil) followed by RP-HPLC with fluorimetric detection. The total PAHs content in the studied samples can be considered generally low. The light PAHs (2–4 rings) were predominant. Virgin olive oils showed the highest values (max. 26 μg/kg). An evident decrease of PAHs contents during alkaline refining was observed (71%, 88% and 85% in sunflower, soybean and olive oils, respectively) being more pronounced in light PAHs. Neutralization and, particularly, deodorization were the more effective steps contributing to the PAHs decrease. Bleaching was responsible for a slight increase in the PAHs content in soybean and olive oils.

Melatonin is a phytochemical in olive oil

Given the numerous observations regarding the positive effects of olive oil consumption and the presence of melatonin in edible plants, we addressed for the first time the question of melatonin determination in virgin olive oil. All the extra virgin olive oil registered designation of origins from Spain and commercial samples of refined olive and sunflower oil were used. Immunoprecipitation and ELISA were combined for melatonin determination. Melatonin is present in olive oil at higher levels in extra virgin olive oil than in refined olive or sunflower oil samples. We concluded that melatonin is part of the phytochemical profile of the olive oil. Particularly, extra virgin olive oil had almost double the melatonin contents of the other refined oils analysed. Thus, melatonin may account for the healthy effects of the Mediterranean diet in which olive oil is the main source of fat.

ANTIOXIDANT ACTIVITY OF DIFFERENT SOLVENT EXTRACTS OF RICE BRAN AT ACCELERATED STORAGE OF SUNFLOWER OIL

ABSTRACT The antioxidant activity of different extracts of rice bran (var. Super Kernel) prepared using a number of solvents (100% methanol, 80% methanol, 100% acetone and 80% acetone) were evaluated in sunflower oil (SFO) under accelerated storage conditions. The crude concentrated extracts of rice bran were added at 600 mg/kg into refined, bleached and deodorized SFO samples and stored under accelerated (65C) conditions for 24 days. Analyses were done every 4 days, and the extent of oxidative deterioration was followed by measurement of activity index, peroxide, p‐anisidine, and conjugated diene and triene values. The overall order of antioxidant efficacy of rice bran extracts as determined by various antioxidant assays was 80% methanolic extract, &gt;100% methanolic extract, &gt;80% acetone extract and &gt;100% acetone extract. The antioxidant activity of rice bran extracts might be attributed to the presence of phenolics and high contents of tocopherol. The results of the present comprehensive analysis demonstrated that extracts of the rice bran of Super Kernel, an indigenous cultivar of Pakistan, are a viable source of natural antioxidants and might be exploited for functional foods and nutraceutical applications.