Antioxidants propyl gallate

Hall et al. (127) compared free solution capillary electrophoresis (FSCE) and micellar elec-trokinetic capillary chromatography (MEKC) techniques with HPLC analysis. Four major food-grade antioxidants, propyl gallate (PG), BHA, BHT, and TBHQ, were separated. Resolution of the 4 antioxidants was not successful with FSCE, but was with MEKC. Separation was completed with excellent resolution and efficiency within 6 min and picomole amounts of the antioxidants were detectable using UV absorption. In contrast, reversed-phase HPLC separation was not as efficient and required larger sample amounts and longer separation time. 

The literature is replete with reports of various allergic-type reactions to preservatives (parabens, chlorocresol), antioxidants (propyl gallate, metabisulphite), surfactants and solvents. The list is too long to be discussed in this article but Ref. contains a... 

Many food additives can be determined fluorimetri-cally, although few are actually assayed routinely using this technique. One of the best examples in this context is the determination of quinine in tonic water and lemonade based on the measurement of its intrinsic fluorescence in sulfuric acid. Although the simultaneous determination of food additives usually involves a chromatographic separation, an alternative method for the determination of two antioxidants, propyl gallate (PG) and butylated hy-droxyanisole (BFIA), in various food samples has been described using a T-format luminescence... 

Lauryl gallate (also termed petrolatum (antioxidant) Propyl gallate, 1% petrolatum... 

Kobayashi, H., S. Oikawa, K. Hirakawa, and S. Kawanishi. 2004. Metal-induced oxidative damage to cellular and isolated DNA by gallic acid, a metabolite of antioxidant propyl gallate. Mutat. Res. Genet. Toxicol. Environ. Mutagen. 558 111-120. 

Xiang, Q., Y. Gao, Y. Xu, and E. Wang. 2007. Capillary electrophoresis-ampero-metric determination of antioxidant propyl gallate and butyrated hydroxyanisole in foods. Anal. Sci. 23 713-717. 

Antioxidants (qv) have a positive effect on oils when present in the proper concentration. Sterols and tocopherols, which are natural antioxidants, may be analy2ed by gas-Hquid chromatography (glc), high performance Hquid chromatography (hplc), or thin-layer chromatography (tic). Synthetic antioxidants maybe added by processors to improve the performance or shelf life of products. These compounds include butylatedhydroxyanisole (BHA), butylated hydroxytoluene (BHT), / fZ-butyUiydroquinone (TBHQ), and propyl gallate. These materials may likewise be analy2ed by glc, hplc, or tic. Citric acid (qv), which functions as a metal chelator, may also be deterrnined by glc. 

Propyl gallate is an antioxidant. It protects against oxidation by hydrogen peroxide and oxygen free radicals in a catalytic manner similar to superoxide dismutase. 

Antioxidants are not important only to the health conscious food manufacturers also rely on these chemicals to maintain the shelf life of their products. Synthetic antioxidants such as butylated hydroxyanisole, butylated hydroxytoluene, propyl gallate and tert-butyl hydroquinone were widely used in food processing to control oxidation and maintain food quality. However, as these synthetic antioxidants are suspected to be carcinogenic they now have restricted use in food (Madahavi and Salunkhe, 1995). Therefore, natural antioxidant sources, especially of plant origin, are of great interest to the food industry. 

C12 to C20, primarily Ci6 to ( is), used as surface lubricants in the manufacture of food-contact articles. The method, which uses ethyl palmitate (Eastman Chemicals No. 1575 Red Label) as an internal standard, has been validated at 200 ppm total FAME [185]. Other FAME standards (methyl palmitate, methyl stearate, methyl oleate, methyl linoleate and methyl linolenate) are available (Applied Science Laboratories) [116], Worked out examples of additive determinations are given in the Food Additives Analytical Manual [116], which also describes a great many of indirect food additives, such as BHA, BHT, TBHQ, l-chloro-2-propanol, DLTDP, fatty acid methyl esters, w-heptyl-p-hydroxybenzoate, propyl-gallate, sodium benzoate, sodium stearoyl-2-lactylate, sorbitol and phenolic antioxidants. EPA methods 606 and 8060 describe the CGC separation of phthalate esters (direct injection) (cf. Figure 4.2). 

The commonest synthetic antioxidants are butylated hydroxyanisole (BHA) and butylated hydroxy toluene (BHT). Other synthetic antioxidants are w-propyl gallate and n-octyl gallate. Any substance that can act as a radical trap will have antioxidant properties. There are strict rules governing the use of antioxidants in foods. Only those substances that are on the permitted list can be used. 

Propyl gallate, antioxidant useful in cosmetics, 7 830t Propylparaben... 

Annex III lays down the conditions of use for permitted preservatives and antioxidants, with lists of foods and maximum levels in each case. Part A lists the sorbates, benzoates and p-hydroxybenzoates, E 200-E 219 part B lists sulphur dioxide and the sulphites, E 220-E 228 part C lists other preservatives with their uses, including nisin, dimethyl dicarbonate and substances allowed for surface treatment of certain fruits, E 249 potassium nitrite, E 250 sodium nitrite, E 251 sodium nitrate and E 252 potassium nitrate, E 280-E 283 propionic acid and the propionates part D lists the antioxidants E 320 butylated hydroxyanisole (BHA), E 321 butylated hydroxytoluene (BHT), E 310 propyl gallate, E 311 octyl gallate, E 312 dodecyl gallate, E 315 eiythorbic acid and E 316 sodium erythorbate. 

Propyl gallate, BHA, BHT, TBHQ, THBP, 4-hydroxymethyl-2,6-di-ferf-butylphenol, thiodipropionic acid and dilauiylthiodipropionic acid may be used provided that the total antioxidant content does not exceed 200 mg kg"1 of the fat or oil content when used according to good manufacturing practice. Anoxomer may be used provided that the total antioxidant content does not exceed 5000 mg kg 1 of the fat or oil content of the food. 

One of the most important advantages of HPLC over spectrophoto-metric methods lies in its specificity and selectivity due to its separation capability. Through chromatographic separations, the analytes of interest can be detected and quantified without interference from the typical matrix that includes excipients, antioxidants, preservatives, and dissolution media. Ion-pair HPLC was used to monitor the dissolution of pentamidine from EVA sustained-release film where polymeric matrices could create significant bias if a spectrophotometric method were used. Due to their strong UV absorbance, the antioxidants and preservatives (e.g., BHA, BHT, ascorbic acid and propyl gallate) are often the major... 

Propyl gallate Antioxidant (approved for use in oral concentrate), antimicrobial activity Prevents autoxidation of oils and peroxide formation in ether. Synergistic effects with other antioxidants such as butylated hydroxyanisole... 

For medical applications, the antioxidant is selected from ascorbic acid, propyl gallate, butylhydroxyanisole, or dibutylhydroxy-toluene (58). 

Rubber antioxidants are commonly of an aromatic amine type, such as dibeta-naphthyl-para-phenylenediamine and phenyl-beta-naphthylamine. Usually, only a small fraction of a percent affords adequate protection. Some antioxidants arc substitute phenolic compounds (butylatcd hydro -vamsole, di-tert-butyl-para-cresol, and propyl gallate). 

Butylatedhydroxyamsole (BHA) was first used in food products in 1940. This continues as one of the commonly used antioxidants, sometimes in combination with butylated hydroxytoluene (BHT), propyl gallate, citric, or phosphoric acids, to obtain a synergistic effect. In foodcontact surfaces. BHT has been used by itself or in combination with thiodipropionates and/or phosphoric acids, to obtain a synergistic effect. Well over 50 million of antioxidants are produced per year commercially in the United Slates alone. 

A qualitative and quantitative HPLC method for analysis of mixtures of 12 antioxidants was described Grosset et al. (121). For the identification of the components present, gradient elution with a convex profile from 35 65 water-methanol to pure methanol is used, on a Waters 5-/xm C18 column, with UV detector. Propyl gallate was not separated by this system. For quantitative analysis, with UV and electrochemical detectors in series, the water-methanol mixture or pure methanol was used as the eluent, under isocratic conditions, with lithium perchlorate as supporting electrolyte. An applied potential ranging from +0.8 to +1.7 V allows detection of all the antioxidants tested. Both modes of detection were very sensitive, with limits of detection as low as 61 pg. 

Antioxidants form only a minor group of cosmetic allergens. Examples are propyl gallate, octyl gallate,66 which may cross-react with other gallates and are also used as food additives, and t-butyl hydroquinone, a well-known allergen in the United Kingdom but not in continental Europe.2... 

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