Antioxidants erythorbic acid

Erythorbic acid is widely used in food applications as an antioxidant. It is also used in oral pharmaceutical applications as an antioxidant. Erythorbic acid is generally regarded as nontoxic and nonirritant when used as an excipient. Erythorbic acid is readily metabolized and does not affect the urinary excretion of ascorbic acid. 

In apphcations where vitamin C activity is unimportant, often D-erythorbic acid (D-araboascorbic acid) can also be used, providing the same antioxidant and reducing properties as L-ascorbic acid. 

Erythorbic acid and sodium erythorbate are very safe products, widely used in the food industry as antioxidants and alternatives to vitamin C. In the water treatment industry, they are strong reducing agents that reduce metal oxides and hydroxides to their more soluble ferrous forms and promote the passivation of boiler waterside surfaces (magnetite formation). 

One excellent UV protector for foods is PABA, a B vitamin. Likewise, many of the same antioxidants we ingest as health supplements—such as vitamin C and a similar chemical, erythorbic acid vitamin E and lecithin, a source of the important nutrients choline and inositol—occur naturally in food. 

An isomer (molecule with the same number and type of atoms but in a different formation) of ascorbic acid called erythorbic acid is often used as a less expensive antioxidant than ascorbic acid. It has little or no effect as a vitamin, but it has the same antioxidant properties. 

Oxidation of the lipid structure in foods containing oils and fats produces carbonyl compounds which are responsible for the flavor and odor associated with rancidity (B-81MI11508) the use of a suitable antioxidant can delay this process. Several heterocyclic compounds are among the antioxidants suitable for use in food ascorbic acid (69) and certain of its derivatives and erythorbic acid. The quinoline derivative (70) is mainly used as an antioxidant in animal feed, but it can also be used to preserve the color of paprika, chili powder and ground chili. 

Another group ol compounds called oxygen scavengers retard oxidation by reducing the available molecular oxygen. Products in this group are water. soluble and include erythorbic acid. C(,HgO(,. and its salt sodium erythorbate, C(,H OsNa. ascorbyl palmitale, C HjsO . ascorbic acid, Ct.llxO, . glucose oxidase, and sulfites. See also Antioxidants. 

The sparkling wine in the receiving tank is cloudy, contains no sugar, and requires clarification, sweetening, and treatment before final bottling. After analysis, the S02 level of the wine is adjusted by adding potassium metabisulfite. Erythorbic acid is added also. These are for antimicrobial and antioxidation purposes. 

D-lso-ascorbic acid (erythorbic acid see Figure 13.1) also has vitamin activity. in vivo and in cell culmre, it has only about 5% of the biological activity of ascorbate, but this seems to be from poor intestinal absorption and tissue uptake. In vitro with purified enzymes, it has the same cofactor activity as ascorbate. Although it is not a namrally occurring compound, erythorbic acid is widely used interchangeably with ascorbic acid, in cured meats and as an antioxidant in a variety of foods. 

Ascorbic Acid and Ascorbic Acid Esters and Saits Vitamin C or ascorbic acid is widespread in nature but sparingly associated with fats of oils because of its hydrophilic nature (95). Ascorbic acid in the free form, salts of sodium and calcium, and esters of stearic and palmitic are commonly used as antioxidants in foods. Erythorbic acid is the D-isomer of naturally present L-ascorbic acid (Figure 10) and is often used as an antioxidant in dried fruits and a cure... 

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... 

Erythorbic acid is a stereoisomer of L-ascorbic acid, and is used as an antioxidant in foods and oral pharmaceutical formulations. It has approximately 5% of the vitamin C activity of L-ascorbic acid. 

These compounds are used as antioxidants in food for humans, animal feeds, plastics, soaps, petroleum products, synthetic rubber, and animal and vegetable oils. The amounts produced annually (metric tons) for use in the United States are BHA (1400) BHT (450) PG (230), and the sum of others including ascorbic acid, sodium and calcium ascorbates, erythorbic acid, and gum guaic (< 230). 

Anilinophenyl methacrylamide N,N -Di (n-octyl)-p-phenylenediamine antioxidant, brewing Erythorbic acid antioxidant, cancer Thioctic acid... 

This chapter is also restricted to those additives deemed contentious by certain health departments and/or the public. These are sulphur dioxide (SO2), sorbate, dimethyldicarbonate (DMDC), ascorbic acid, erythorbic acid, and nisin. These additives are either antimicrobial and/or antioxidant in action, and probably represent the two most problematic areas in winemaking and brewing. In addition, as the use of sulphur dioxide in winemaking is under review and is the most contentious of the additives, a greater proportion of this chapter is devoted to minimising and/or optimising its usage. 

Figure 8. Comparison of antioxidative effect of various antioxidants with melanoidin. Symbols are x, control BHA , erythorbic acid A, BHT and o, melanoidin.

L-ascorbic acid is the naturally occurring form of ascorbic acid and has the most biological activity. The o-ascorbic acid as well as d- and L-isoascorbic acids (erythorbic acid, lAA) have only marginal vitamin C activity. However, lAA is used in the food industry as an antioxidant, even though it has only about 5%... 

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]. 

Modern antioxidant technology is merely about 70 years old. Only four synthetic antioxidants are widely used in foods, namely the phenolic antioxidants BHA, BHT and diphenol TBHQ (which are antioxidants of low polarity), while more polar antioxidants are esters of gallic acid (gallates) and esters of ascorbic acid. Polar antioxidants are ascorbic and erythorbic acids and their salts. Ascorbic acid, its derivatives and its analogue erythorbic (isoascorbic) acid are described in Section 5.13.1. 

Synthetic antioxidants (4-hexyhesorcinol, see Section 10.2.3.4) and natural antioxidants approved in the EU as food additives, such as ascorbic acid, its salts, fatty acid esters and analogues (erythorbic acid) and tocopherols are included in Chapter 5. Natural compounds with antioxidative activity occurring in herbs and spices, including the extracts of rosemary (E392), are addressed in Section 10.3.3.7. 

Erythorbic acid and sodium erythorbate may be used for preserved and semi-preserved fish products and frozen and deep-frozen fish at a concentration of 1500 mg/kg. The amount of these antioxidants allowed for preservation of cured and preserved meat products is only 500 mg/kg (expressed as erythorbic acid). The use of 4-hexylresorcinol (4-hexyl-1,3-benzenediol) is permitted up to 2 mg/kg as a colour retention agent for treatment of crustacean meat (fresh and frozen), namely to prevent black spots arising by enzymatic browning reactions, known as shrimp melanosis. 

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. 

The reaction mechanism is detailed in the section deahng with the oxidation of Hpids (see Section 3.8.1.8). The primary antioxidants include aU authorised substances ascorbic acid and erythorbic (isoascorbic) acid and their derivatives, tocopherols and phenoHc antioxidants (Table 11.4). The secondary antioxidants include, for example, cysteine, cysteine-containing peptides (such as glutathione), methionine, Hpoic acid and other naturally occurring compounds, which are not however used as antioxidants. A synthetic secondary antioxidant used in the past was 3,3 -thiodipropionic acid dilaurate (11-7). 

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