Antioxidants ascorbyl palmitate

The selection of an appropriate antioxidant depends on factors such as stability, toxicity, efficiency, odor, taste, compatibility with other ingredients, and distribution phenomena between the two phases. Antioxidants that give protection primarily in the aqueous phase include sodium metabisulfite, ascorbic acid, thioglycerol, and cysteine hydrochloride. Oil-soluble antioxidants include lecithin, propyl gal-late, ascorbyl palmitate, and butylated hydroxytoluene. Vitamin E has also been used, but its virtue as a natural antioxidant has been the subject of some controversy. 

Tocopherols are not as effective as antioxidants as the synthetic antioxidants, e.g. BHA or BHT. The antioxidant effect of tocopherols is increased by mixing them with ascorbyl palmitate, ascorbic acid, lecithin or citric acid. Typical confectionery applications are the use of tocopherols with ascorbyl palmitate or lecithin or citric acid in the fat phase of toffees or caramels. Chewing gum base can be treated with a- and y-tocopherol to extend the shelf life. 

Interest has been shown in using derivatives of ascorbic acid as antioxidants. One such compound is ascorbyl palmitate. In the structure of ascorbyl palmitate, the 2- and 3-positions are occupied by hydroxyl groups the 6-position contains the substituted fatty acid. Other derivatives, synthesized by Seib and associates were ascorbate-2 phosphate and ascorbate 2-triphosphate (27). Both of these compounds were reported to inhibit lipid oxidation in ground meat as measured by chemical means (2). Ascorbate-2-phosphate was also found to inhibit MFD in beef as measured by sensory means (2). The ascorbate-2-triphosphate was not tested as an inhibitor of MFD in this study, but... 

Sodium, potassium, and calcium salts of ascorbic acids are called ascorbates and are used as food preservatives. These salts are also used as vitamin supplements. Ascorbic acid is water-soluble and sensitive to light, heat, and air. It passes out of the body readily. To make ascorbic acid fat-soluble, it can be esterified. Esters of ascorbic acid and acids, such as palmitic acid to form ascorbyl palmitate and stearic acid to form ascorbic stearate, are used as antioxidants in food, pharmaceuticals, and cosmetics. 

Koops, J. 1964B. Antioxidant activity of ascorbyl palmitate in cold stored cultured butter. Neth. Milk Dairy J. 18, 38-51. 

Rustan et al. (123) used an isocratic HPLC method for the determination of alpha-, gamma-, and delta-tocopherol, BHT, BHA, PG, OG, DG, NDGA, TBHQ, ascorbyl palmitate, and beta-carotene in foods. An RP18 column was used in experiments, and seven mobile phases based on various combinations of acetonitrile, methanol, water, and tetrahydrofuran were tested. Trials with carrot juice, dried milk formula for infants, and aperitif cakes showed that all 12 antioxidants could be determined by a single isocratic HPLC analysis. The optimum mobile phase... 

Ingredients Carbonated water. Concentrated fruit juices (pineapple, grapefruit) (5% when reconstituted). Citric acid. Acidity regulator (sodium citrate). Artificial sweeteners (aspartame, saccharin). Flavourings. Preservative (sodium benzoate). Antioxidants (ascorbic acid, ascorbyl palmitate). Colour (lutein)... 

The antioxidants butylated hydroxyanisole (BHA), butylated hydroxytolu-ene (BHT), tm-butylhydroquinone (TBHQ), propyl gallate, ascorbyl palmitate and citric acid were evaluated for potential to reduce NOx emissions from a single cylinder, direct-injection, air-cooled, naturally aspirated Yanmar engine (Hess et al, 2005). BHA and BHT reduced NOx emissions by 4.4 and 2.9%, respectively, but the other antioxidants evaluated did not exhibit any beneficial effects (see Table 1.2). Antioxidants may impede NOx formation by inhibiting the formation of combustion-derived radicals. 

Figure 2-19 Effect of Copper Concentration on Protective Effect of Antioxidants in Lard. (A) lard + 0.01% BHT, (B) lard + 0.01% ascorbyl palmitate, (C) lard + 0.005% BHT and 0.05% ascorbyl palmi-tate. Source From J. Pokorny, Stabilization of Fats by Phenolic Antioxidants, Can. Inst. Food Sci. Technol. J., Vol. 4, pp. 68—74, 1971.

Antioxidant Agent that inhibits oxidation and thus is used to prevent deterioration of preparations by oxidative process Ascorbic acid, ascorbyl palmitate, butylated hydroxyanisole, butylated hydroxytoluene, hypophosphorus acid, monothioglycerol, propyl gallate, sodium ascorbate, sodium bisulfite, sodium formaldehyde, sulfoxylate, sodium metabisulfite... 

Oxidative stability of 00-3 fatty acids can be increased using free radical scavengers. TBHQ (t-butyUiydroquinone) at a concentration of 0.02% has successfully slowed down the oxidation of menhaden oil for up to 40 days, compared with 3 days for the control group (83). a-Tocopherol and butylated hydroxytoluene (BHT) alone or in combination increased the oxidative stability of EPA and DHA (84). The most notable success in fish oil stabilization has been achieved with ternary antioxidant systems, which contain a- or y-tocopherol concentrates, ascorbic acid (or ascorbyl palmitate), and lecithin (85). 

Commercially, tocopherol is available as a pure all-rac-a-tocopherol, mixed tocopherols having various contents of a-, p-, y-, or 8-tocopherols (diluted in vegetable oil) and synergistic mixtures containing tocopherols, ascorbyl palmitate or other antioxidants, and synergists such as lecithin, citric acid, and carriers. Extraction of tocopherols from natural sources and chemical synthesis of tocopherols are well described by Schuler (100). 

Table 5 shows the maximum levels permitted by the FDA for the four major synthetic antioxidants (BHA, BHT, PG, and TBHQ) in specific applications (51). The regulatory status for these antioxidants in the USA, Canada, and Europe is given in Table 6 Table 7 summarizes their status in other countries for which a listing could be found. In addition to the major synthetic antioxidants discussed above (BHA, BHT, TBHQ, gallates, erythorbic acid, and ascorbyl palmitate), several other... 

Synthetic antioxidants, such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propyl gallate (PG), ascorbyl palmitate, and tertiary-butyl-hydroquinone (TBHQ), are used in soybean cooking oils and frying fats (230). These antioxidants are typically added at 0.01% for one antioxidant and 0.02% total for two or more. Natural antioxidants, derived from sage, rosemary, and green tea, are increasingly popular because of consumer preferences for natural food ingredients (231). 

Salad and cooking oils have varying amounts of natural antioxidants, mostly toco-pherols. With the introduction of synthetic antioxidants, it has been customary to supplement the natural antioxidants with the synthetic ones. Most commonly used synthetic antioxidants are butylated hydroxy anisole (BHA), butylated hydroxy toluene (BHT), propyl gallate (PG), ascorbyl palmitate, and tertiary butyl hydro-quinone (TBHQ). As a result of the questionable health implications of BHA and BHT, use of BHA and BHT is becoming rare. In recent times, TBHQ, because of its superior performance, has been used more extensively than the other synthetic antioxidants. Application and status of antioxidants have been reviewed (75). 

Alpha-tocopherol is a highly lipophilic compound, and is an excellent solvent for many poorly soluble drugs.Of widespread regulatory acceptability, tocopherols are of value in oil- or fat-based pharmaceutical products and are normally used in the concentration range 0.001-0.05% v/v. There is frequently an optimum concentration thus the autoxidation of linoleic acid and methyl linolenate is reduced at low concentrations of alpha tocopherol, and is accelerated by higher concentrations. Antioxidant effectiveness can be increased by the addition of oil-soluble synergists such as lecithin and ascorbyl palmitate. " ... 

Ascorbyl palmitate is primarily used either alone or in combination with alpha tocopherol as a stabilizer for oils in oral pharmaceutical formulations and food products generally 0.05% w/v is used. It may also be used in oral and topical preparations as an antioxidant for drugs unstable to oxygen. The combination of ascorbyl palmitate with alpha tocopherol shows marked synergism, which increases the effect of the components and allows the amount used to be reduced. 

For antioxidant formulation for fats and oil products, the number of additives and the ratio of the additives depends in a large part on the food product to be treated. For example, one can examine the results of Pongracz (641) wherein ascorbyl palmitate and -tocopherol were added singularly and combined to six different fats and oils, and the differences in response were noted. The combination antioxidant was most effective in animal fats, butter fat, and lard, and ascorbyl ascorbate was quite effective alone in vegetable and peanut oils, soybean, palm oil, and sunflower oil (Table XXII). The procedure for adding ascorbyl palmitate to an oil product is as follows ascorbyl palmitate (20-50 g) is dissolved in heated (100°C) oil or fat (5 kg), and the resulting warm... 

Magnesium ascorbyl phosphate (MAP) is more effective than ascorbyl palmitate (AP), as the protection of its active function by esterification protects the MAP against oxidation and provides an antioxidant effect that is of better quality and longer lasting than that of ascorbyl palmitate, a molecule in which the enediol function of the 2 carbon atom is not protected by esterification. 

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