Influence of Tunisian aromatic plants on the prevention of oxidation in soybean oil under heating and frying conditions (original) (raw)
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Chemical Papers
The present study was conducted to determine and compare the oxidative stability of soybean and sunflower oils using differential scanning calorimetry (DSC). These edible oils were enriched with marjoram (Origanum majorana L.), thyme (Thymus vulgaris L.), and oregano (Origanum vulgare L.) extracts at three different concentrations and synthetic antioxidant (BHA). The fatty acid composition of studied oils was determined by gas chromatography mass spectrometry to evaluate the content of unsaturated fatty acids that are sensitive to oxidation process. Oil samples were heated in the DSC at different heating rates (4.0, 7.5, 10.0, 12.5, and 15.0 °C min −1) and oxidation kinetic parameters (activation energy, pre-exponential factor, and oxidation rate constant) were calculated. The results showed that the oxidative stability of sunflower oil samples enriched with oregano extracts and soybean oil supplemented with thyme extracts was improved compared to samples without the addition of herbal plant extracts and the synthetic antioxidant.
The Effect of Selected Herb Extracts on Oxidative Stability of Vegetable Oils
Croatica Chemica Acta
The aim of this study was to investigate the effect of different herb extracts on the oxidative stability of hemp, flax, sesame and sunflower seed oils by means of Rancimat test. The dominant phenolic acids in herb extracts were detected by HPLC, while fatty acid profiles of oils, before and after oxidation, were determined by GC-FID. As expected, autoxidation increased the content of saturated fatty acids. The sesame oil showed the longest oxidative stability (3.43 h), while the shortest induction period was obtained for the flax oil. Lemon balm and oregano extracts accelerated the oxidation of hemp and flax oil, while in all other cases the addition of extracts had a positive effect on oil oxidative stability. The best results were obtained for lemon balm extract added to sesame and sunflower oil which resulted with OSI values of 1.33 and 1.48, respectively, while extremely prooxidative activity was obtained for lemon balm extract added to the hemp oil.
Food oxidation presents one of the major deterioration in food industry. It minimizes food shelf-life, production of undesirable flavor or color. The introduction of synthetic antioxidant is a better solution to stop these reactions; although many studies demonstrated the negative effect of using these antioxidants. The use of natural antioxidants like food additives, actually present a successful strategy to satisfy consumer needs. Currently, consumers demand for healthy food is increasing , also rejecting foods with synthetic antioxidant due to diseases that can be caused by the consumption of these products. In this study, rosemary and laurel fresh leaves were added to virgin olive oil and stored in different modes. Physicochemical, sensory evaluation and oxidation stability were performed to determine the most likely natural aromatic plants that could be used to conserve olive oil. Experimental results showed that the aromatization of olive oils with rosemary or laurel stored in the dark led to increasing the value of total phenolic contents and preserving them against autoxidation. This increase led to show lower free acidity, peroxide and thiobarbituric acid reactive substances. The trained panel preferred olive oil aromatized by rosemary fresh leaves stored in the dark.
Journal of the Science of Food and Agriculture, 2014
BACKGROUNDPlant extracts have been used as an alternative to the use of synthetic antioxidants in order to preserve oils from oxidative degradation. Additionally, these extracts add special flavors and aromas to the food. Thus, the objective of this study was to evaluate the effect of hydroethanolic extracts of fresh and freeze‐dried rosemary in the oxidative stability of soybean oil under accelerated storage in an oven.RESULTSThe application of the extracts in the oil showed that that freeze‐dried extract was better in reducing the formation of oxidation products, showing 8.6 meq kg−1 of peroxides after 20 days of storage. On the other hand, the mixture of the natural extract with t‐butylhydroquinone conferred better oxidative stability index until the 20th day, 9.7 h. Both extracts prevented the loss of tocopherol, not differing between each other (P > 0.05), and present approximately 505 mg kg−1 of residual tocopherols. The sensory evaluation revealed that consumers accepted e...
Journal of Food and Dairy Sciences (Print), 2014
Soybean oil is the most popular types of edible oils in Egypt. It is characterized by rapidly due to oxidation and rancidity processes. This study has been conducted to study the various transactions mixing and heating on the stability of soybean oil. And has been mixing soybean oil to sunflower oil by ratio (1: 1) and has been conducting the process of primary heating at 50 ₒ C for 3 hours and then was treated with natural antioxidants extracted from waste of fruits and grains factories for example mango peels, apple pomace and wheat bran with concentrations (200, 400 and 600 ppm) and TBHQ as synthetic antioxidants with concentration (200 ppm). Results for the identification and separation of phenolic compounds of the antioxidants using HPLC being as follows: chlorogenic, salicylic, vannillic, benzoic and ellagic acids were the predominant obtained phenolics compounds. also the results obtained from total phenolic compounds as gallic acid being (14.53: 144.13 mg / g) and 2,2 diphenyl1-picrylhydrazyl(DPPH) results showed that mango peel extract gave the highest antioxidant activity(96.59%) compared to other extracts. Treated oil were thermally heated at 65 ₒ C for 96 hours and some chemical properties (acid number, peroxide value and TBA value) were evaluated , our results showed an observed increase in acid value of untreated oil samples compared with treated samples with different antioxidants extracts , whereas high gradual increase in the constants of oxidation and rancidity (peroxide and TBA values). Peroxide and TBA values were reached a maximum values which peroxide values being 22.57 ml.eqv./Kg oil for untreated oil sample and 12.96ml.eqv./Kg oil for treated oil sample with mango peels extract, while TBA values being 2.330 mg malonaldhyde/Kg oil for untreated oil sample compared with and 0.700 mg malonaldhyde/Kg oil in oil samples treated mango peel extract after 96 hours of heating. From then evident from the previous results that the additions of mango peel extract concentration of 600 ppm led to the improvement of the qualities of soybean oil mixture and thermally laboratories (chemical and natural) and delay rancidity and oxidation processes.
Advances in Biological Sciences Research, 2022
Edible oils have been used widely in food processing, especially processes with thermal treatment such as frying. In the frying process, oils are usually used repetitively and trigger the presence of lipid oxidation which results in the degradation of fatty acids. This degradation of fatty acids then results in the reduction of quality in oil which includes decreasing nutritional value. The reduction of quality in oil is very dangerous as it can migrate into the food that can be consumed by humans and trigger several negative health effects such as carcinogenic properties. In order to preserve the quality of the oil, antioxidants are used to improve its oxidative stability. As there are some restrictions and drawbacks of using synthetic antioxidants, natural antioxidants are more preferable to be used in the food industry. In this paper, the subjects that were reviewed are oils with high polyunsaturated fatty acids content and natural antioxidants that have the potential to improve oxidative stability of the oils which are rosemary extract, sesame seed extract, green tea extract and fruit peels extract. The optimum extraction method and active compounds contained in the extract also be discussed. The methodology of this paper is using journal reviews through Google Scholar. The keywords used to search related journals include natural antioxidant, antioxidant activity, rosemary extract, green tea extract, sesame seed extract, frying, heating, fatty acids, optimum extraction, edible oils, oxidative stability, lipid oxidation. Secondary data was obtained from other research which related to the changes of fatty acid composition after processing food with edible oils that have high unsaturated fatty acid content and analysis of several parameters for measuring oxidative stability. The usage of natural antioxidants which are rosemary extract, sesame seed extract, and green tea extract has been proven to improve oxidative stability of the oils and prevent degradation of polyunsaturated fatty acids. Polyphenolic compounds inside the extracts are the ones that contribute to its antioxidative activity. The optimum extraction method of the extracts is by using solvent extraction and the difference of solvent used is mainly based on the polarity of the extracts
Effect of Immersed Herbs on the Oxidative Stability of Edible Oils
Periodica Polytechnica Chemical Engineering, 2015
The improvement of the oxidative stability of edible oils is in the focus of scientific and consumer interest. In the present work the effect of immersion of herbs in edible oils was performed and changes in oxidative stability were measured. Sage and oregano were chosen as herbs and linseed oil, corn germ oil as well as walnut oil as lipid media. Immersion parameters were 3%, 5%, and 7% (w/w) herb/oil, duration: 10 days, temperature: 30°C. Oxidative stability was measured by Rancimat test and FRAP analysis. Results showed that the oxidative stability of the highly sensitive oils -such as linseed and walnut oil- was successfully improved by immersion of herbs. Corn germ oil, which contains a high amount of tocopherols, became similarly more stable, however, only moderately.
Modern Chemistry & Applications, 2017
The main objective of this study is to evaluate the antioxidant properties of oregano on refined soybean oil as a result of microwave and induction cook top heating. Oxidation changes were determined by common traditional parameters such as acid value, free fatty acid value, peroxide value as well as by Fourier transform infrared (FTIR) spectroscopy. It has been observed from studies that oregano has powerful antioxidant effect in microwave heated oil samples whereas it does not show any antioxidant properties on induction cooktop heated samples.
International Journal of Food Properties, 2017
The barberry fruits are used as food flavoring. Berberis integerrima seeds are used as waste product in barberry's processes. This study describes the potential use of B. integerrima seed oil (BSO) as a natural antioxidant. 2,2diphenyl-1-picryl hydrazyl scavenging activity and ferric-reducing antioxidant power of the oil alcoholic extract were determined. Protective effect of BSO in stabilizing soybean oil was further evaluated based on the peroxide values, thiobarbituric acid values, conjugated dienes and trienes, and Rancimat test during storage. Results of gas chromatography (GC-FID) showed that more than 90% of the fatty acids were linolenic (ω-3), linoleic (ω-6), and oleic (ω-9) acids. Total phenolic compounds were 323.0 mg Gallic acid/kg oil. Chromatographic separation of their sterols and tocopherols (HPLC) demonstrated that β-sitosterol, campesterol, stigmasterol cholesterol, sitostanol, Δ5-avenasterol, Δ7-avenasterol, clerosterol, and α-tocopherol and γ-tocopherol were present in the BSO, respectively. The IC 50 of the oil alcoholic extract was less than the commercial antioxidants, including butylated hydroxyanisole and butylated hydroxytoluene. The statistical results indicated that BSO has significant effects on soybean oil stability on most days.
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.