Comparison of oxidative stability of different edible oils (original) (raw)
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Polish Journal of Food and Nutrition Sciences, 2008
The resistance of edible oils to oxidative degradation, leading to rancidification, is an important parameter for assessing the quality of oil. This paper presents a new promising method to diagnose the volatile compounds which are products of oil oxidation reactions. Our experiment was carried out using a combined method of UV irradiation as an oxidation acceleration technique, headspace solid-phase microextraction (HS-SPME) as an extraction technique and capillary gas chromatography (GC) as an assay technique. Method precision and sensitivity expressed as RSD (<19%) and LOD (between 18 and173 ng/mL) are satisfactory. The induction period set on hexanal / t-2-nonenal ratio (IP=6.67 h) is comparable with those obtained with the Rancimat method (4.64-6.73 h).
Evaluation of oxidative quality parameters in imported edible oils in Iran
British Food Journal, 2013
Purpose-The purpose of this paper is to determine the peroxide value (PV), p-anisidine and total oxidation value (TOTOX) values of imported edible oils in Iran. Design/methodology/approach-A total 196 oil samples of different origin and types (corn, olive, canola and grape-seed oil) were collected randomly from Boushehr port of Iran and a total 27 oil samples were also collected from frying pans used to deep-fry local food items at different restaurants in Boushehr city. Findings-The PVs ranged from 1.38-13.74, 3.90-20.00, 0.83-2.99, 0.67-11.95 and 0.00-9.96 mequiv/kg found in refined olive oil, virgin olive oil, canola oil, grape-seed oil and corn oil, respectively. The results showed that PVs of 18.37 percent of imported oil and 62.96 percent of frying oils from restaurant exceeded the maximum acceptable limits set by Institute of Standards and Industrial Research of Iran (ISIRI) (2-20 mequiv/kg for different types of oils). P-anisidine value ranged from 0.89-27.56 mequiv/kg in imported oils and 2.21-30.76 mequiv/kg found in frying oil from restaurants. The TOTOX value increased linearly with peroxide values and p-anisidine values. It ranged from 0.89-76.62. Originality/value-Fried foods are very common in Iranians' diet. A major portion of the edible oils in Iran are imported from other countries through Boushehr port. ISIRI has set maximum acceptable limit for PVs in different oils imported to the country. The possible effects of storage on oil oxidation are the original criteria of this research. The results of the study indicate that inappropriate storage of edible oils and their use in frying applications at restaurants facilitate oil oxidation and deterioration.
Oxidative Stability of Selected Edible Oils
Molecules, 2018
The aim of the study was to examine and compare oxidative stability of refined (peanut, corn, rice bran, grapeseed, and rapeseed) oils. The oils were subject a Schaal Oven Test (temperature 63 ± 1 °C) and a Rancimat test (temperature 120 °C) and their stability was compared at the 1st and 12th month of storage. Changes in the peroxide (PV) and anisidine (AnV) values in the thermostat test were the fastest in rapeseed oil and grapeseed oil. The best quality was preserved by peanut and corn oils both in the first and the twelfth month of storage. The induction times for the rice bran, corn, peanut, and rapeseed oils were similar from 4.77 h to 5.02 h in the first month and from 3.22 h to 3.77 h in the twelfth month. The shortest induction times were determined for grapeseed oil: 2.4 h and 1.6 h, respectively. A decrease of oxidative stability of about 30% was found in all the oils after 12 months of storage. The PV of 10, determined in the thermostat and Rancimat tests, were achieved ...
Journal of agricultural and food chemistry, 2003
Modifications of virgin olive oil subjected to accelerated storage were evaluated by HS-SPME analysis. To find a suitable marker of oxidative degradation, the volatile compounds showing variable concentration during the oxidative process have been identified and quantified by SPME coupled to GC-MS and GC-FID, respectively. The SPME analysis results were then compared with the parameters usually applied to assess the oxidative status of lipids, such as peroxide value, spectrophotometric absorbance, and loss of unsaturated fatty acids. Finally, the assessment of nonanal has been suggested as a marker of oxidative degradation. This rapid, inexpensive, and reliable method may allow screening of oils prior to testing by a panel of assessors.
Quantitative determination of major oxidation products in edible oils by direct NP-HPLC-DAD analysis
Journal of chromatography. A, 2018
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...
Chemical Composition and Oxidative Stability of Selected Plant Oils
Journal of the American Oil Chemists' Society, 2010
Scientific data on the oxidative stability of borage oil, Camelina sativa oil, linseed oil, evening primrose oil and pumpkin seed oil are scarce. Chemiluminescence (CL) methods most commonly used to determine the oxidative stability of oils include measurement of hydroperoxide, intensity of light emitted during the accelerated oxidation process performed at high ([100°C) temperatures or assisted by forced flow of air/oxygen through the sample. The aim of this study was to investigate the chemical composition and oxidative stability of selected vegetable oils available on the Polish market. Oxidative stability was determined using a fast, novel chemiluminescence-based method, in which light emitted during oxidation process conducted at 70°C in the presence of some catalyzing Fe 2? ions is measured. A reaction of the applied type has not been reported so far. High contents of tocopherols and phytosterols were found in the analyzed oil samples. Oxidative stability of the samples was in most cases higher than the stability of refined rapeseed oil, a relatively stable substance from the oxidation point of view.
Chemometric assessment of thermal oxidation of some edible oils
Journal of Thermal Analysis and Calorimetry, 2010
The effect of microwave heating was studied in six varieties of edible oil. Variations in physicochemical properties were observed and compared with the data obtained by hot plate heating. Fourier-transform infrared spectra of the oils showed substantial variations after both types of heating in the region of hydrogen's stretching (C-H) vibration, region of double bond's stretching (C=O), and fingerprint region. The visible spectra of mustard and olive oil showed the reduction in carotenoid, flavonoid, and chlorophyll pigments after heating. The oil samples were discriminated as saturated, monounsaturated, and polyunsaturated fats using chemometric techniques on physical and spectroscopic measurements.
Polish Journal of Food and Nutrition Sciences, 2011
Trends in Edible Vegetable Oils Analysis. Part A. Determination of Different Components of Edible Oils - a Review This review presents recent approaches applied to analysis of edible oils. In the last decade increasing attention has been paid to human diet concerning also edible oils and fats as a source of healthy energy. One of the major problems related to fats are oil oxidation reactions which decrease the nutritive value of edible oils. This paper describes methods developed to analyse different components of edible oils. The stress is put on methods used to assess oxidation stability of edible oils, their purity and approaches to determine their geographical origin.
Oxidative stability of olive, corn and soybean oil under different conditions
To follow the relative rates of oxidative deterioration in edible oils, refined olive, corn and soybean oils were analyzed periodically for their peroxide value (PV), p-anisidine value (p-AV) and iodine value (IV), following exposure to air or air-light for 30 days. Changes in the above values of the oils were also examined and after their use for deep-frying of French fries at 180 °C for varying periods of time, namely 30, 60 and 90 min. PV and p-AV values increased in the order: deep-frying > air-light exposure > air exposure while the values with respect to the oils increased in the order: soybean > corn > olive. Decrease in IV followed the same pattern, i.e. deep-frying > air-light > air and soybean > corn > olive. Deep-frying of French fries in corn oil was also carried out in the presence of caffeic, ferulic, vanillic acid and crude tea extract as antioxidants. All antioxidants effectively reduced the oxidation rate in the oil, as detected by decrease in PVs and p-AVs and relatively low reduction rate in IVs for all the frying times. The order of antioxidative activity was caffeic acid > vanillic acid > ferulic acid > tea extract.