Butylated hydroxytoluene direct oxidation

Compounds that are in direct contact with air when in the final product, for example as in powder products or in soap, are particularly at risk from oxidation, and the head space above the product is likely therefore to become rich in the breakdown products of oxidation. For this reason the packaging usually allows for a certain amount of "breathing" so as to let these "off-odors" escape rather than their being reabsorbed into the product. A number of products exist, generally classed as antioxidants, for example, BHT (butyl hydroxytoluene), that help to inhibit these oxidation reactions. These antioxidants are often added to citrus oils, or to compounds to prolong their shelf life, or to the final product. 

Stabilization of Foods. The oxidation of food containing fats and oils results in a loss of sensory appeal and eventually rancidness. FDA regulations covering the use of direct food additives are stringent and few new materials have been regulated. A number of products in use today, such as citric acid (33), and CC-tocopherol [59-02-9] (41), are in the GRAS list. The most commonly used materials are butylated hydroxytoluene [128-37-0] (1), -propyl gallate [129-79-9] (42), a-tocopherol, and butylated hydroxyanisole [25013-16-5] (43). The concentrations allowed in food are less than 0.02%. Metal deactivators such as citric acid (33), ethylenediaminetetraacetic acid (32) and its salts, and calcium chelate are used to deactivate transition metal oxidation catalysts. 

Anticarcinogens that either directly antagonize carcinogens, or more likely prevent their activation, are also present in many foods naturally or are added to them. Included in this list of good guys are vitamins A, E, and C, some Bs, chlorophyll, carotene, butylated hydroxytoluene (BHT), and anisole (BHA). Many of these substances are effective antioxidants that presumably may inhibit oxidative carcinogenic activation. Vitamin C is also a potent inhibitor of nitrosamine formation. 

Antixmdants The direct action of oxygen in the air is the chief cause of the destruction of the fats in food. Carbon-carbon double bonds in polyunsaturated fatty acids are particularly susceptible. Oxidation produces a complex mixture of volatile aldehydes, ketones, and acids that causes a rancid odor and taste. Foods kept wrapped, cold, and dry are relatively protected from air oxidation. The most common antioxidant food additives are butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), which act by releasing a hydrogen atom from their — OH groups as a free radical (H ). 

Numerical identification and analysis of critical conditions for liquid-phase oxidation of ethylbenzene inhibited by butylated hydroxytoluene. The critical phenomena are studied and analyzed in detail for the liquid-phase autooxidation of organic substances, the carbochain polymers in the presence of inhibitors [32-34,52], Investigations in this direction cmrently are also urgent for predicting the antioxidant activity of compoimds, including the bioantioxidants [53-67],... 

As an example a model of die liquid-phase oxidation of the ethylbenzene in the presence of inhibitors, the iora-substituted phenols and the butylated hydroxytoluene, was selected. The identified dynamics of die value contribution of steps in the reaction mechanism is complicated. The dominant steps for die different time intervals of the inhibited reaction were determined. The inhibition mechanism of die ethylbenzene oxidation by sterically unhindered phenols is conditioned by establishing equilibrium (7.24) in the reaction of the chain carrier, the peroxyl radical, with the inhibitor s molecule (within sufficiently wide interval of the inhibitor s initial concentration), followed by the reaction radical s quadratic termination with the participation of the phenoxyl radical. The value analysis has established that the efficient inhibitor with low dissociation energy of the phenolic 0-H bond promotes shifting the mentioned equilibrium from the chain carrier to the direction of the phenoxyl radical formation. 

The commercial nonionic surfactants do not absorb radiation in the visible spectrum. The simplest form of spectrophotometric analysis of nonionics is the direct measurement of the UV absorbance of the sample. The ethoxylated alkylphenols are the only compounds which can be readily determined by this method, with a maximal absorbance at about 223 nm and another peak at 276 nm (69). Ethoxylated amides may be determined in model systems by their absorption of light at 202 nm (70), but many other compounds found in typical samples also have absorbance in this region. Because of the sensitivity of direct UV analysis to interference, it can only be used in well-defined situations. Interferences often encountered in nonionic surfactants are oxidation inhibitors like butylated hydroxytoluene. 

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