首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
A HPLC with gradient elution method for the determination of the synthetic phenolic antioxidants (SPAs) propyl gallate (PG), tertiary butyl hydroquinone (TBHQ), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) in food items is described. A C18 column served as the stationary phase; the gradient elution was formed by acetonitrile and water:acetic acid (1%). The UV detector was set at 280 nm. Under the recommended conditions, separation of the four SPAs was achieved in less than 8 min. Analytical characteristics of the HPLC method such as limit of detection, linear range, and reproducibility were evaluated. Extraction parameters were optimized for the recoveries of the SPAs in different types of food items (cooking oil, margarine and butter, and cheese). Before the HPLC separation, the SPAs were extracted with methanol/acetonitrile (1:1, v/v) and were subjected to vortex/ultrasonic treatment. The extracts were next kept in a freezer (∼2 h) to precipitate co-extracted components. Recoveries of the SPAs when spiked to cooking oil, margarine, butter and cheese at 50 and 200 mg l−1 were in the ranges 93.3–108.3% for PG, 85.3–108.3% for TBHQ, 96.7–101.2% for BHA and 73.9–94.6% for BHT. The method was applied to the determination of SPAs in 38 food items (16 cooking oils, ten margarine, six butter and six cheese samples). The levels of SPAs in positive samples are all below the legal limits of Malaysia.  相似文献   

2.
A cloud-point extraction (CPE) method using Triton X-114 (TX-114) nonionic surfactant was developed for the extraction and preconcentration of propyl gallate (PG), tertiary butyl hydroquinone (TBHQ), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) from edible oils. The optimum conditions of CPE were 2.5% (v/v) TX-114, 0.5% (w/v) NaCl and 40 min equilibration time at 50 °C. The surfactant-rich phase was then analyzed by reversed-phase high-performance liquid chromatography with ultraviolet detection at 280 nm, using a gradient mobile phase consisting of methanol and 1.5% (v/v) acetic acid. Under the studied conditions, 4 synthetic phenolic antioxidants (SPAs) were successfully separated within 24 min. The limits of detection (LOD) were 1.9 ng mL(-1) for PG, 11 ng mL(-1) for TBHQ, 2.3 ng mL(-1) for BHA, and 5.9 ng mL(-1) for BHT. Recoveries of the SPAs spiked into edible oil were in the range 81% to 88%. The CPE method was shown to be potentially useful for the preconcentration of the target analytes, with a preconcentration factor of 14. Moreover, the method is simple, has high sensitivity, consumes much less solvent than traditional methods, and is environment-friendly. Practical Application: The method established in this article uses less organic solvent to extract SPAs from edible oils; it is simple, highly sensitive and results in no pollution to the environment.  相似文献   

3.
A cloud-point extraction (CPE) method using Tergitol TMN-6 (TMN-6) non-ionic surfactant was developed for the extraction and preconcentration of propyl gallate (PG), tertiary butyl hydroquinone (TBHQ), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) in edible oils. The optimum conditions of CPE were 1.5 % (v/v) Tergitol TMN-6, 1 % (w/v) NaCl, ultrasound-assist 15 min at 49 KHz, 20 min equilibrated at 45 °C, and centrifugation for 10 min at 3,000 rpm. The surfactant-rich phase was then analyzed by reversed-phase high-performance liquid chromatography (HPLC) with ultraviolet detection at 280 nm, under gradient separation, using methanol and 1.5 % (v/v) acetic acid. Under the study conditions, four synthetic phenolic antioxidants (SPAs) were successfully separated within 24 min. Limits of detection in the studied edible oils were in the range of 1.6 to 9.0 ng mL?1. The high recoveries of the spiked edible oils were obtained in the range 90–98 %. The CPE method has been shown to be a potentially useful methodology for the preconcentration of the target analytes, with a preconcentration factor of 25. This method was compared with cloud point extraction (using Triton X-114) and liquid–liquid extraction (using methanol).  相似文献   

4.
A biparameter sensor using flow injection with solid‐phase spectrophotometry for the simultaneous determination of butylated hydroxyanisole (BHA) and n‐propyl gallate (n‐PG) in fatty foods and cosmetics is proposed. The method is based on different transient retentions of these antioxidants when carried with methanol‐water 30:70%, vol/vol, through a flow cell packed to a 25‐mm height with C18 silica. Each antioxidant was determined by measuring its intrinsic absorbance at its residence time (40 s at 272 nm for n‐PG; 200 s at 288 nm for BHA; calibration: 5.0 to 300.0 μg/mL; RSD: 1.7%) by flow technique and diode‐array detector. Resolution of the BHA‐n‐PG mixture in ratios between 1:10 and 10:1 is possible.  相似文献   

5.
The aim of this study was to investigate the antioxidant activities of persimmon seed extracts (PSE) using different solvents such as ethanol, methanol, acetone, and their aqueous 80% solvents. The EC50 values of the extracts from absolute ethanol (EE) and methanol (ME) in 2, 2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical–scavenging assay were 49.71 and 51.15 μg mL?1, respectively, while the EC50 of butylated hydroxyanisole (BHA) was 70.82 μg mL?1. However, the EC50 value of reducing power for the absolute acetone extract (AE) was higher (210.06 μg mL?1) than that of BHA (212.67 μg mL?1). Although the absolute ME had the highest antioxidant activity, it exhibited the lowest total phenolics and flavonoids. In contrast, the antioxidant activities of the aqueous solvent extracts showed a good correlation with total phenolics and flavonoids when compared to the absolute solvent extracts. The results showed that PSE could potentially be used as an inexpensive source of natural antioxidant in food and pharmaceutical industries.  相似文献   

6.
Antibacterial and antioxidant potential of essential oil, extract and its fractions of Bidens frondosa Linn were evaluated. Sixty‐one components representing 95.41% of the total oil were identified. The essential oil (7.5 μL disc?1), methanol extract and its different organic subfractions (0.5 μg disc?1) of B. frondosa displayed a great potential of antibacterial activity against Staphylococcus aureus (ATCC 6538 and KCTC 1916), Listeria monocytogenes ATCC 19116, Bacillus subtilis ATCC 6633, Pseudomonas aeruginosa KCTC 2004, Salmonella enteritidis KCTC 12021 and Enterobacter aerogenes KCTC 2190. Antioxidant activity was evaluated by using 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) assay. The free radical scavenging activity of ethyl acetate (EtOAc) fraction was superior to all other fractions (IC50 = 11.96 μg mL?1), which was higher than synthetic antioxidant butylated hydroxyanisole, (IC50 = 18.27 μg mL?1). Furthermore, the amount of total phenolic compounds was determined and its content in EtOAc fraction was the highest as compared to methanol extract or other fractions. The results indicate that the oil and extracts of B. frondosa could serve as an important bio‐resource of antimicrobial agents and antioxidants for using in the food industries.  相似文献   

7.
A new and efficient method for the determination of synthetic phenolic antioxidants (SPAs) has been developed by using micellar electrokinetic capillary chromatography (MECC) with electrochemical detection. Under the optimum conditions, all analytes were successfully separated within 13 min at the separation voltage of 18 kV in a 20 mmol/L borate running buffer (pH 7.4) containing 25 mmol/L sodium dodecyl sulfate. The excellent linearity was obtained in the concentration range from 5.0 × 10−4 to 2.0 × 10−6 mol/L and the detection limits (S/N = 3) of propyl gallate (PG), tert-butylhydroquinone (TBHQ), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) range from 2.9 × 10−7 to 2.7 × 10−6 mol/L. This method has been proved to be effective and successfully applied for the determination of SPA in food products, providing a promising and convenient entry to monitor the superscale use of phenolic antioxidants.  相似文献   

8.
The synthetic phenolic antioxidants butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert-butyl hydroquinone (TBHQ) were pre-concentrated by stir-bar sorptive extraction and thermally desorbed (SBSE-TD) before analysis by GC-MS. Several parameters affecting the derivatisation step and both SBSE extraction and thermal desorption were carefully optimised. When the analyses of BHA and TBHQ in their acetylated, silylated and underivatised forms were compared, the best results were obtained when the in-situ derivatisation procedure with acetic anhydride was employed. Quantification was carried out using carvacrol as the internal standard, providing quantification limits of between 0.11 and 0.15 ng ml?1, depending on the compound. Recovery assays for samples spiked at two concentration levels, 1 and 5 ng ml?1, provided recoveries in the 81–117% range. The proposed method was applied in the analysis canned soft drinks and the analytes were found in five of the 10 samples analysed.  相似文献   

9.
《Food microbiology》1987,4(3):239-249
The effect of selected phenolic compounds on the membrane-bound ATPase activity of two strains of Staphylococcus aureus was studied. These phenolic compounds were: butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tertiary butylhydroquinone (TBHQ), propyl gallate (PG), p-coumaric, ferulic, caffeic acids, methyl paraben and propyl paraben. Cytoplasmic membrane-bound ATPase activity was measured in the presence of 0, 150, 300, 600 and 1200 μg ml−1 of each phenolic compound. Among all the compounds studied, only BHA was found to significantly stimulate the activity of the enzyme. In contrast, some of the compounds were found to significantly inhibit the activity of the enzyme as was the case of TBHQ, PG, p-coumaric acid, ferulic acid and caffeic acid. The remaining compounds did not influence the activity of the ATPase at any of the concentrations tested. Strain LP ATPase as stimulated less by BHA and inhibited to a greater extent by TBHQ and PG than was the enzyme from strain A100. In contrast, LP ATPase was less inhibited by p-coumaric acid and not affected by either ferulic or caffeic acid.  相似文献   

10.
A glassy carbon electrode (GCE) was modified with eosin Y that was electrodeposited on GCE via continuous cycling between ??1.6 and 1.5 V (vs Ag/AgCl). This electrode was characterized by scanning electron microscopy and electrochemical impedance spectra. The resulting electrode exhibited excellent electrocatalytic activity toward the oxidation of butylated hydroxyanisole (BHA) and tert-butyl hydroquinone (TBH2Q); in addition, the oxidation products of BHA and TBH2Q were found to be the same, which was studied by CV and in situ FT-IR spectroelectrochemistry. Under the optimized condition, the oxidation peak currents were linear to BHA/TBH2Q in the range from 0.10 to 7.00 μg mL?1 with the detection limits of 0.01 μg mL?1 (S/N?=?3) for BHA and 0.015 μg mL?1 (S/N?=?3) for TBH2Q, respectively. Moreover, the reproducibility and repeatability of the electrode were determined. The proposed method was successfully applied in the simultaneous determination of BHA and TBH2Q in several edible oil samples, and satisfactory results when compared with those obtained using high-performance liquid chromatography.  相似文献   

11.
This study reported the chemical composition, phenolic content, antioxidant and anti‐lipase activity of oregano and Lippia essential oils. The major compounds found in oregano essential oil were γ‐terpinene (32.10%), α‐terpinene (15.10%), p‐cymene (8.00%) and thymol (8.00%). In Lippia essential oil, α‐limonene (76.80%) and 1,8‐cineole (4.95%) represented the major compounds. Oregano essential oil had higher phenolic content (12.47 mg gallic acid mL?1) and DPPH scavenging activity (IC50 0.357 μg mL?1) than Lippia essential oil (7.94 mg gallic acid mL?1 and IC50 0.400 μg mL?1, respectively). Both essential oils had similar antioxidant indexes (about 1.2) determined by Rancimat. Moreover, oregano essential oil had also higher anti‐lipase activity (IC50 5.09 and 7.26 μg mL?1). Higher phenolic content in the essential oils was related with higher scavenging and anti‐lipase activities. Oregano and Lippia essential oils could be used as natural antioxidants on food products.  相似文献   

12.
A method for the simultaneous determination of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) in food was developed using square-wave voltammetry (SWV). The determination of these phenolic antioxidants was carried out using a cathodically pre-treated boron-doped diamond electrode (BDD) and an aqueous-ethanolic (30% ethanol, v/v) 10 mmol L−1 KNO3 solution (pHcond. 1.5) as supporting electrolyte. In the SWV measurements using the BDD electrode, the oxidation peak potentials of BHA and BHT present in binary mixtures were separated by about 0.3 V. The attained detection limits for the simultaneous determination of BHA and BHT (0.14 and 0.25 μmol L−1, respectively) are lower than the ones by voltammetric techniques reported in the literature. The proposed method was successfully applied in the simultaneous determination of BHA and BHT in food products, with results similar to those obtained using a high-performance liquid chromatography method, at a 95% confidence level.  相似文献   

13.
The release study of natural antioxidants, i.e., ascorbyl palmitate and α-tocopherol, and synthetic phenolic antioxidants including butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propyl gallate, and tert-butylhydroquinone (TBHQ) from polylactic acid (PLA) film into food simulants were accomplished. PLA antioxidant films were placed in contact with 95, 50, and 10 % ethanol at 40 and 20 °C. Released antioxidants were regularly measured by high-performance liquid chromatography system for 60 days. Ascorbyl palmitate was completely degraded during film preparation and is not a suitable antioxidant for PLA antioxidant-active packaging. The diffusion coefficient (D) and partition coefficient (K) of antioxidants were calculated based on obtained data. Diffusion of the antioxidants from PLA to the simulants showed a Fick’s behavior with the diffusion coefficient (D) value between 10?9 and 10?11 cm2 s?1 with 0–100 % of release. Faster and higher release of antioxidants occurred at 40 °C according to Arrhenius law. At 40 °C, TBHQ in 95 % ethanol decomposed to 2-tert-butyl-1,4-benzoquinone and other quinone derivatives, and α-tocopherol in 50 % ethanol decomposed to some unknown neoformed compounds. Antioxidants molecular weight, Log P, simulant polarity, and temperature were the most influencing factors on antioxidants release rate from PLA films in contact with food simulants. The D and K coefficients of studied antioxidants from PLA in three food simulants and two temperatures can be used to create PLA antioxidant-active packaging to continually control the oxidation reactions in diverse foodstuffs to ensure higher food qualities. The PLA antioxidant-active packaging approach also permits to reduce the amounts of directly added antioxidants in foods to provide safer foods.  相似文献   

14.
BACKGROUND: Sudan I, a synthetic azo dye, is considered to be a genotoxic carcinogen and is prohibited in foodstuffs for any purpose at any level worldwide. In this study, a sensitive and specific direct competitive enzyme‐linked immunosorbent assay (dc‐ELISA) for fast detection of Sudan I in food samples was developed for the first time. The monoclonal antibody against Sudan I was used as capture protein, while horseradish peroxidase labeled Sudan I conjugate prepared by the periodate method via ovalbumin (OVA) as a bridge was used as enzyme tracer. RESULTS: The standard curve of dc‐ELISA for Sudan I was constructed in the range 0.1–100 ng mL?1 and the assay time was within 80 min. Sensitivity was 2.6 ng mL?1 and the limit of detection was 0.08 ng mL?1. Cross‐reactivity values of the assay with Sudan II, III and IV were 5.78%, 1.72% and 0.64%; no cross‐reactivity was found with six other edible colorants. The assay was tolerated to 30% of methanol and 10% of acetonitrile without significant loss of IC50. Recoveries of spiked Sudan I in five different samples including chilli powder, tomato sauce, hotpot seasoning and chilli sauce I and II were within 88.4–113.2% and the intra‐assay relative standard deviation was less than 14%. The dc‐ELISA was confirmed by conventional high‐performance liquid chromatography and the correlation coefficient of the two methods was 0.9902. CONCLUSION: The proposed dc‐ELISA method provides an alternative method for sensitive, specific and fast determination of Sudan I in food samples. Copyright © 2011 Society of Chemical Industry  相似文献   

15.
The antioxidant activities of ethanol extracts of rosemary (Rosmarinus officinalis L.) (RE) were tested in natural sunflower oil stored at 60 °C by measuring their peroxide values (POV), thiobarbituric acid‐reactive substances (TBARS), free fatty acid (FFA) content and p‐anisidine value (AnV) after regular intervals compared with synthetic antioxidants. After 3 weeks of storage at 60 °C, sunflower oil containing 200 mg kg?1 rosemary extracts showed lower POVs (75.7 ± 0.47  meq kg?1), thiobarbituric acid‐reactive substances (TBARS)(0.161 ± 0.002 μg mL?1), FFA contents (0.45 ± 0.04 mg g?1) and AnV (12.4 ± 0.02) than the control sample. Sunflower oil containing 200 ppm butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert‐butylhydroquinone (TBHQ) showed POVs (204 ± 0.68, 159 ± 0.55, 20 ± 0.49 meq kg?1), thiobarbituric acid‐reactive substances (TBARS) (0.171 ± 0.002, 0.184 ± 0.002, 0.069 ± 0.001 μg mL?1), FFA contents (0.34 ± 0.03, 0.46 ± 0.03, 0.2 ± 0.01 mg g?1) and AnV (14.7 ± 0.03, 16.5 ± 0.04, 6.77 ± 0.01), respectively, after 3 weeks of storage at 60 °C. These results illustrate that rosemary extracts exhibited very strong antioxidant activity, almost equal to that of synthetic antioxidants (BHA and BHT).  相似文献   

16.
A rapid, accurate and organic solvent saving procedure has been developed for the GC/MS determination of three phenolic antioxidants butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA) and butyl hydroquinone (TBHQ) in vegetable oils. The method involves two-step microextraction and a centrifugal procedure in a 2 mL autosampler vial, consuming only 50 mg sample and total 1 mL acetonitrile. Recoveries of the phenolic antioxidants when spiked to soya bean oil, peanut oil and cereal cooking oil at 50, 200 and 250 mg/kg, respectively were in the ranges 95.6-104.3% for BHT, 99.7-107.5% for BHA and 93.6-103.8% for TBHQ with the relative standard deviation (RSD) were less than 3% for their independent measurements. The developed method was repeatable and could be applied to determine trace amounts of phenolic antioxidants in vegetable oils.  相似文献   

17.
Antioxidant and antiproliferative activities of three rosemary extract formulations (VivOX 20, VivOX 40 and Inolens 50) with different contents of carnosic acid, carnosol and methylcarnosol were tested in vitro. Electron spin resonance measurements revealed that Inolens 50 extract that contained highest amount of carnosic acid was the most potent scavenger of hydroxyl (concentration of extract where 50% of its maximal scavenging activity is observed, that is, EC50, 109.54 μg mL?1), superoxide anion (EC50 = 7.94 μg mL?1) and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) (EC50 = 27.4 μg mL?1)‐free radicals. Comparison of the radar charts of standard antioxidants and rosemary extracts showed similarity between antioxidant characteristics of Inolens 50 and chlorogenic and caffeic acids. Tested rosemary extracts exhibited significant (P ≤ 0.01) antiproliferative effect in cervix epitheloid carcinoma (HeLa), breast adenocarcinoma (MCF7) and colon adenocarcinoma (HT‐29) cell lines. In both MCF7 and HeLa cell lines, the extracts yielded very low IC50 values (concentration of extract needed to inhibit cell growth by 50%), the most pronounced being for Inolens 50 in MCF7 (IC50 = 9.95 μg mL?1) and VivOX 20 in HeLa cell line (IC50 = 10.02 μg mL?1). The obtained results may provide support for the use of tested rosemary extracts as nutraceuticals and phytopharmaceuticals.  相似文献   

18.
BACKGROUND: Medium‐ and long‐chain triacylglyerols (MLCT) enzymatically esterified using Lipozyme RM IM lipase has very low oxidative stability as it does not contain any antioxidants. The aim of this work was to study the ability of various antioxidants to increase the oxidative stability of palm‐ and soybean‐based MLCT blends which assist to bring up the oxidative stability of both MLCT blends. In this study, the effectiveness of rosemary extracts, sage extracts, tert‐butylhydroquinone (TBHQ) and mixtures of tert‐butyl‐4‐hydroxyanisole (BHA) and tert‐butyl‐p‐hydroxytoluene (BHT) in protecting against oxidation of various MLCT blends was investigated. RESULTS: Blending of MLCT oil with either palm olein or soybean oil improved its smoke point values and oxidative stability. TBHQ addition to both palm‐ and soybean‐based MLCT blends increased oxidative stability. Combination of BHA and BHT showed no significant improvement (P > 0.05) in ability to protect blends from oxidation compared to natural antioxidants such as sage or rosemary extracts. CONCLUSION: Blended oils with 500 g kg?1 MLCT and 500 g kg?1 palm olein (MP5) were the most suitable for use at high temperature based on the fatty acid composition of the MLCT blends, which subsequently had an effect on thermal oxidative stability. In general, addition of either natural or synthetic antioxidant assisted in improving the antioxidative strength of both MLCT blends. MLCT blends with added TBHQ showed the highest thermal oxidative stability among the antioxidants used. Copyright © 2008 Society of Chemical Industry  相似文献   

19.
研究了油炸食品中化学合成酚类抗氧化剂--丁基羟基茴香醚(BHA)、二叔丁基对甲酚(BHT)、没食子酸丙酯(PG)、特丁基对苯二酚(TBHQ)的检测,采用超高效液相色谱-串联质谱法测定,以反相C18为分离柱,乙腈-甲醇水体系为流动相进行梯度洗脱,采用负离子检测模式,外标法定量。4种抗氧化剂呈良好线性关系(R2=0.9953~0.9998),PG方法检出限为2.0μg/kg,BHA、TBHQ检出限为200μg/kg,BHT检出限为500μg/kg。回收率为79%~96%,相对标准偏差为0.9%~5.3%,方法准确、灵敏、重现性好,可用于油炸食品中抗氧化剂的检测。  相似文献   

20.
The study presents changes in the phenolic levels, antioxidant and anti‐inflammatory potential of purple basil leaves caused by different chemical elicitors: arachidonic acid (AA), jasmonic acid (JA) and β‐aminobutyric acid (BABA). The application of the all tested elicitors increased the concentration of phenolic compounds, including flavonoids and phenolic acids; especially, in comparison with control (457.62 μg g?1 FW), the rosmarinic acid level significantly increased after AA and JA treatment ‐ 705.0 and 596.5 μg g?1 FW, respectively. Phenolics from AA‐elicited plants showed the highest anti‐inflammatory activities designated as lipoxygenase (EC50 = 1.67 mg FW mL?1) and cyclooxygenase inhibition (EC50 = 0.31 mg FW mL?1). Elicitors' treatments (especially AA and JA) may be a very useful biochemical tool for improving the production of phenolic compounds in purple basil leaves.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号