Vitamin ascorbyl palmitate

L-Ascorbic acid biosynthesis in plants and animals as well as the chemical synthesis starts from D-glucose. The vitamin and its main derivatives, sodium ascorbate, calcium ascorbate, and ascorbyl palmitate, are officially recognized by regulatory agencies and included in compendia such as the United S fates Pharmacopeia/National Formula (USP/NF) and the Food Chemicals Codex (FCC). 

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. 

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. 

Oxygen scavengers can remove oxygen in a closed system. The most widely used compounds are vitamin C and related substances, ascorbyl palmitate, and erythorbic acid (the D-isomer of ascorbic acid). 

Ascorbic L, acid. See Vitamin C Ascorbyl palmitate Ascorbyl palmitate as synergist Ashing... 

Ascorbyl palmitate and ascorbyl stearate are synthetic derivatives of ascorbic acid. Ascorbic palmitate is soluble in lipid-containing foods because of its relatively good hydrophobicity (88). Ascorbyl palmitate is hydrolyzed by the digestive system to provide nutritionally available ascorbic acid and palmitic acid, but health claims cannot be made for its vitamin C contribution. 

By this synergistic mechanism, tocopherols and ascorbic acid can mutually reinforce one another by regenerating the oxidized form of the other. Radical exchange reactions among lipid radicals, tocopherols, and ascorbic acid are the basis of numerous approaches for stabilizing oil and foods with their mixtures. It is however important to note that vitamin C is not soluble in the lipid phase that is most susceptible to oxidation. This was the reason why L-ascorbic esters were developed, e.g., ascorbyl palmitate that has a lipid solubility superior to that of ascorbic acid. Mixtures of ascorbyl palmitate with tocopherols are well known for their synergistic activity. 

Vitamin C (ascorbic acid) and its fat-soluble derivative ascorbyl palmitate also have antioxidant activity under certain conditions. The determination of vitamin C is discussed elsewhere. 

Muscle tissues contain a multi-component antioxidant system consisting of lipid-soluble compounds (a-tocopherol, ubiquinone), water-soluble compounds (ascorbate, histidine-dipeptides) and enzymes (superoxide dismutase, catalase, glutathione peroxidase). Lipid oxidation in meats can be effectively controlled by the use of various phenolic compounds derived from spice extracts, by vitamin E supplementation of animal diets, and by processing of cured meat with sodium nitrite. Various natural antioxidant formulations containing mixtures of tocopherols, ascorbyl palmitate and citric acid show synergistic effects in stabilizing cooked and frozen meat. Synthetic antioxidants, BHA, TBHQ, propyl gallate (see Chapter 9) and combinations with citric acid, ascorbic acid or phosphates are also effective formulations used to retard lipid oxidation in... 

Certain derivatives of vitamin C (for example, erythrobic acid and ascorbyl palmitate) are used as antioxidants in food products to prevent rancidity, to prevent browning of fruit, and to cure meat. Erythrobic acid (D-araboascoibic acid) is poorly absorbed and has little antiscorbutic activity. 

Ascorbyl palmitate, a derivative of ascorbic acid, is actually a lipophilic vitamin C and has been shown to be as biologically active as its original hydrophilic counterpart. Since both vitamin C and palmitate esters are natural food ingredients, ascorbyl palmitate is widely used in the food industry as a natural preserver of oils and fats. 

Vitamins (see Section 8.6), often added to cosmetic formulations, act as antioxidant preservatives due to their general antioxidant properties towards free radicals. Examples are retinol (vitamin A) and its precursor j5-carotene, tocopherol (vitamin E) and ascorbic acid (vitamin C). Moreover, vitamin derivatives, such as retinyl acetate, retinyl palmitate, ascorbyl palmitate, magnesium ascorbyl phosphate and tocopheryl acetate among others, are also employed as antioxidant agents. 

The main sources of vitamin C are green vegetables and citrus fruit. Animal tissue contains vitamin C, mainly in the kidneys and liver. The level of vitamin C in food is rapidly reduced during cooking or storage due to oxidation or water dissolution. It is added to food as an antioxidant (with no specified limit on the level of use) or as a supplement (with a maximum recommended daily intake of 3000mg/day). The forms admitted are L-ascorbic acid (AA), L-ascorbyl 6-palmitate, sodium, calcium, or potassium L-ascorbate [403]. 

One of the main problems of topical application of vitamin C is that it is extremly unstable, so hydrophilic derivatives like sodium ascorbyl phosphate and lipophilic esters with fatty acids were synthesized to improve stability.43,44 However, an efficient increase in vitamin C levels after topical application of different ascorbic acid derivatives including magnesium ascorbyl phosphate, ascorbyl-6-palmitate, and dehydroascorbic acid to porcine skin could not be shown.42... 

The aim of the manuscript is to determine the diffusion coefficients and other relevant electrochemical parameters of antioxidants in water, micellar systems and organic solvents. As the first approach, we employed vitamin C (L-ascorbic acid, AA) and propyl gallate, (PG), and their lipophilic derivatives ascorbyl-6-palmitate (AA16) and lauryl gallate, (LG), because they are well-known bioactive... 

L-ascorbic acid (AA) and L-dehydroascorbic acid (DHAA) are the two main C vitamers occurring in nature [1]. In food analysis, the valuation of the vitamin C total content should account for both forms, since DHAA is readily reduced to AA in the animal body. D-isoascorbic acid (D-IAA), also known as erythorbic acid or D-araboascorbic acid, has analogous reductive properties but only 5% of the antiscorbutic activity of L-AA this epimer is a by-product of vitamin C, and is approved within the European Community as an antioxidant additive [62]. The capability of LC to distinguish the two ascorbic acid isomers and their primary oxidation products is very useful for analyzing processed foods. Forms used for supplementation are AA, sodium-, calcium-, or potassium-L-ascorbate and L-ascorbyl 6-palmitate [4]. 

Sodium ascorbate and ascorbic acid esters, such as ascorbyl 6-palmitate (5-111) and ascorbyl 2-phosphate (5-113), are fully bioavailable, while ascorbyl 2-sulfate (5-114) is a completely inactive vitamin form. Phosphate and sulfate are about 20 times more stable to oxidation than the free acid. D-lsoascorbic acid (5-107) shows only 5-20% activity, 6-deoxy-L-ascorbic acid (5-115), found in fungi, has about 30% activity and the bound ascorbic acid form ascorbigen has 15-20% of the activity of ascorbic acid. Ascorbic acid 2-0-P-D-glucoside, systematic name 2-0-(P-D-glucopyranosyl)-L-ascorbic acid (5-116), has the same biological activity as ascorbic acid and is also stable against oxidation. 

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