Ascorbate, sodium

L-Ascorbic acid monosodium salt E301 3-oxo-L-gulofurano-lactone sodium enolate SA-99-, vitamin C sodium. 

Sodium ascorbate is used as an antioxidant in pharmaceutical formulations, and also in food products where it increases the effectiveness of sodium nitrite against growth of Listeria monocytogenes in cooked meats. It improves gel cohesiveness and sensory firmness of fiberized products regardless of vacuum treatment. 

It is also used therapeutically as a source of vitamin C in tablets and parenteral preparations. 

Sodium ascorbate occurs as a white or slightly yellow-colored, practically odorless, crystalline powder with a pleasant saline taste. 

Hygroscopicity not hygroscopic. Sodium ascorbate adsorbs practically no water up to 80% relative humidity at 20°C and less than 1% w/w of water at 90% relative humidity. 

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Bohman and colleagues described a reverse-phase HPLC method for the quantitative analysis of vitamin A in food using the method of standard additions. In a typical example, a 10.067-g sample of cereal is placed in a 250-mL Erlenmeyer flask along with 1 g of sodium ascorbate,... 

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). 

Specifications for ascorbic acid, sodium ascorbate, calcium ascorbate, and ascorbyl palmitate are found in the Umted States Pharmacopeia J National Formula ... 

Erythorbic acid is supplied as white granular crystals or a powder of sodium erythorbate monohydrate C6H706Na H20, having a fivesided ring and a very reactive ene-diol structure (-COH=COH—) it is a sterioisomer of sodium ascorbate, with a MW of 216.1. It is approved under 21CFR 182.304, GRAS. 

N-Nitrosamine inhibitors Ascorbic acid and its derivatives, andDC-tocopherol have been widely studied as inhibitors of the N-nitrosation reactions in bacon (33,48-51). The effect of sodium ascorbate on NPYR formation is variable, complete inhibition is not achieved, and although results indicate lower levels of NPYR in ascorbate-containing bacon, there are examples of increases (52). Recently, it has been concluded (29) that the essential but probably not the only requirement for a potential anti-N-nitrosamine agent in bacon are its (a) ability to trap NO radicals, (b) lipophilicity, (c) non-steam volatility and (d) heat stability up to 174 C (maximum frying temperature). These appear important requirements since the precursors of NPYR have been associated with bacon adipose tissue (15). Consequently, ascorbyl paImitate has been found to be more effective than sodium ascorbate in reducing N-nitrosamine formation (33), while long chain acetals of ascorbic acid, when used at the 500 and lOOO mg/kg levels have been reported to be capable of reducing the formation of N-nitrosamines in the cooked-out fat by 92 and 97%, respectively (49). 

One to 5 g material was mixed by a glass rod with 1 mL/g material of "stopping solution", that contained 25 mg/mL of ammonium sul-famate, 25 mg/mL of sodium ascorbate, and 2.0-2.5 mg/mL of cis-2,6-dimethylmorpholine (cis-DMM), and was adjusted to pH 1 with H2S0. The pH of the slurry was readjusted to 1 with concentrated H2S0. The mixture was stirred with 10 g Celite 560 (from Johns Manville Corp. previously sifted to remove< 60 mesh particles), and packed dry in a "Monoject" plastic 50 mL syringe barrel (Shermwood Industries) prepacked with 8 g Celite. The column was eluted (without flow-rate control) with 100 mL... 

Iqbal et al. (2) reported two checks to demonstrate that NMOR formation was not artifactual, (a) Addition of sodium ascorbate to the blended mouse did not significantly decrease the NMOR yields. However, at the pH of the homogenate (around 7), ascorbate does not reduce nitrite and hence could not have prevented NMOR formation (3). (b) The NMOR yield was reduced> 907 when morpholine was gavaged after exposure of the mice to N0 > or was added to the homogenate derived from NO -exposed mice. 

Sander and Burkle (31) were the first to induce tumors by feeding nitrite and amines or amides. The tumors were attributed to in vivo formation of the N-nitroso compounds, probably in the stomach. When pregnant rats were gavaged with ethylurea and nitrite, hydrocephalus and nervous system tumors were induced in the offspring. Both these effects were prevented when sodium ascorbate was gavaged together with the ethylurea (21, 32). 

Using a piperazine and nitrite system, lung adenoma induction was approximately proportional to piperazine dose and to the square of nitrite dose, when precursor concentrations were varied (33). When sodium ascorbate was added to the food together with the amine or urea and NaNO was added to drinking water, the number of lung adenomas was reduced, compared to the group without sodium ascorbate ( ). 

The incidence of liver tumors due to morpholine and nitrite was reduced from 65% in the absence of to 49% in the presence of sodium ascorbate, and the latent period was nearly doubled, from 54 to 93 weeks, indicating in vivo nitroso-morpholine (NMOR) production was probably about 50% inhibited (10). 

The addition of celite or HyfloSupercel to increase the contact surface with the extraction solvent and help filtration is often utilized during extraction. In case of interaction of such filter aids with the food, treated sand can be employed instead. Weak bases such as NaHCOj, MgC03, or CaC03 (1 g/10 g sample) to neutralize acids liberated from tissues and antioxidants (0.1% BHT, 5% pyro-gallol, ascorbic acid, and sodium ascorbate) to avoid oxidation can be added during extraction. ... 

FIG. 2 The surface pressure-area isotherms of PS II core complex with different concentrations of salt in the subphase. Subphase, lOmM tris-HCl, pH 8.0, 2mM sodium ascorbate and concentrations of 100, 200, and 500mM NaCl. Temperature, 23.0 0.5°C. 

The addition of terminal alkynes to carbon-carbon double bonds has not been explored until recently, possibly because C=C double bonds are not as good electrophiles as C=N or C=0. In 2003, Carreira et al. reported the first conjugate addition reaction of terminal alkynes to C=C catalyzed by copper in water. The reaction proceeded with derivatives of Meldrum s acid in water in the presence of Cu(OAc)2 and sodium ascorbate (Eq. 4.35).59 However, this method was limited to C=C double bonds with two electron withdrawing groups. 

Chemicals Ascorbate, Potassium Phosphate, Ethylene DiamineTetraacetic Acid (EDTA), Sodium Ascorbate, H202 Polyvinylpyrrolidone (PVP). 

With rapid mixing of the chloroauric acid/carbonate solution, quickly add 1ml of a 7 percent sodium ascorbate solution prepared in water. Maintain the solution cooling in an ice bath. Higher temperatures will create larger particle sizes. The color of the solution at this point will turn to a purple-red. 

A buffer comprises (1) a weak acid and a salt of that acid, (2) a weak base and a salt of that base, or (3) it may contain an acid salt. We define an acid-base buffer as a solution whose pH does not change after adding (small amounts of) a strong acid or base . Sodium ascorbate is a favourite buffer in the food industry. 

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