Activity of vitamin C are generally destroyed by heat treatment of food, especially when there are traces of metals such as copper, but it is resistant to freezing. Vitamin C is probably one of the most unstable among the vitamins soluble in water. In nature there are only L-form of ascorbic and dehydroascorbic acid. Vitamin C is very soluble in water and methanol, and about five times lower in ethanol. Ascorbic acid is well oxidized by air oxygen, especially in the presence of heavy metal ions (such as: copper, iron, etc.). In the absence of oxygen, ascorbic acid can withstand heat up to 100°C. Physical and chemical propertieslDOI: * To whom correspondence should be addressed. Abstract The solubility of l-(+)-ascorbic acid in water, ethanol, methanol, propan-2-ol, acetone, acetonitrile, ethyl acetate, and tetrahydrofuran was measured by a gravimetrical method from (293 to 323) K, and the solubility data were correlated against temperature. The solubility of l-(+)-ascorbic acid in water and methanol was high compared with other solvents.
PDF w/ Links | Citing ArticlesRelated ContentCitation data is made available by participants in CrossRef's Cited-by LinkingFor a more comprehensive list of citations to this article, users are encouraged to perform a search in SciFinder. Effect of Temperature on the Deliquescence Properties of Food Ingredients and Blends , , , , and 2013 AbstractPDF w/ LinksLevo vs. Dextro 2011AbstractPDF w/ LinksSolubility of Vitamin C in Water, Ethanol, Propan-1-ol, Water + Ethanol, and Water + Propan-1-ol at (298.15 and 308.15) K , , and , 2010 AbstractPDF w/ LinksInfluence of Simultaneous Variations in Temperature and Relative Humidity on Chemical Stability of Two Vitamin C Forms and Implications for Shelf Life Models , and 2010 AbstractPDF w/ LinksSolubility of β-Artemether in Methanol + Water and Ethanol + Water from (288.85 to 331.95) K , , and 2009 AbstractPDF w/ LinksEffect of Headgroup Chirality in Nanoassemblies. Self-Assembly of d-Isoascorbic Acid Derivatives in Water , , , , and 2009 Abstract
Sodium benzoate is a substance which has the chemical formula NaC7H5O2. It is a widely used food preservative, with an E number of E211. It is the sodium salt of benzoic acid and exists in this form when dissolved in water. It can be produced by reacting sodium hydroxide with benzoic acid. Sodium benzoate is a preservative. As a food additive, sodium benzoate has the E number E211. It is bacteriostatic and fungistatic under acidic conditions. It is most widely used in acidic foods such as salad dressings (vinegar), carbonated drinks (carbonic acid), jams and fruit juices (citric acid), pickles (vinegar), and condiments. It is also used as a preservative in medicines and cosmetics.[4] Concentration as a food preservative is limited by the FDA in the U.S. to 0.1% by weight.[5] Sodium benzoate is also allowed as an animal food additive at up to 0.1%, according to AFCO's official publication. Sodium benzoate is used as a treatment for urea cycle disorders due to its ability to bind amino acids.
[8] This leads to excretion of these amino acids and a decrease in ammonia levels. Recent research shows that sodium benzoate may be beneficial as an add-on therapy (1 gram/day) in schizophrenia.[11] Total Positive and Negative Syndrome Scale scores dropped by 21% compared to placebo. Sodium benzoate is used to treat hyperammonemia. Sodium benzoate has been shown to halt the progression of Parkinson's in mice. Sodium benzoate is also used in fireworks as a fuel in whistle mix, a powder that emits a whistling noise when compressed into a tube and ignited. The mechanism starts with the absorption of benzoic acid into the cell. If the intracellular pH falls to 5 or lower, the anaerobic fermentation of glucose through phosphofructokinase decreases sharply,[13] which inhibits the growth and survival of microorganisms that cause food spoilage. Sodium benzoate is produced by the neutralization of benzoic acid with sodium hydroxide.[14] Sodium benzoate can also be prepared by adding benzoic acid to a hot concentrated solution of sodium carbonate until effervescence ceases.
The solution is then evaporated, cooled and allowed to crystallize or evaporate to dryness, and then granulated. In the United States, sodium benzoate is designated as generally recognized as safe (GRAS) by the Food and Drug Administration.[15] The International Programme on Chemical Safety found no adverse effects in humans at doses of 647–825 mg/kg of body weight per day. Cats have a significantly lower tolerance against benzoic acid and its salts than rats and mice. A paper published in the March 2015 Journal of the Science of Food and Agriculture found that sodium benzoate has been replaced by potassium sorbate in the majority of soft drinks in the United Kingdom to avoid the use of anything the consumer might consider an additive, particularly in connection with colours and preservatives. Main article: Benzene in soft drinks In combination with ascorbic acid (vitamin C, E300), sodium benzoate and potassium benzoate may form benzene, a known carcinogen. When tested by the FDA, most beverages that contained both ascorbic acid and benzoate had benzene levels that were below those considered dangerous for consumption by the World Health Organization (5 ppb).
[20] Most of the beverages that tested higher have been reformulated and subsequently tested below the safety limit.[20] Heat, light and shelf life can increase the rate at which benzene is formed. Research published in 2007 for the UK's Food Standards Agency (FSA) suggests that certain artificial colors, when paired with sodium benzoate, may be linked to hyperactive behavior. The results were inconsistent regarding sodium benzoate, so the FSA recommended further study.[23] The Food Standards Agency concluded that the observed increases in hyperactive behavior, if real, were more likely to be linked to the artificial colors than to sodium benzoate.[23] The report's author, Jim Stevenson from Southampton University, said: "The results suggest that consumption of certain mixtures of artificial food colours and sodium benzoate preservative are associated with increases in hyperactive behaviour in children. . . . Many other influences are at work but this at least is one a child can avoid."
Sodium benzoate may trigger or exacerbate symptoms or episodes of attention-deficit/hyperactivity disorder, or ADHD, according to the Mayo Clinic. The condition is most common in children but it can be present in adults as well, and affected individuals may be forgetful, have difficulty concentrating and following directions or display impulsiveness. In response to consumer insistence on a more natural product, the Coca Cola Company is in the process of phasing sodium benzoate out of Diet Coke. The company has stated it plans to remove sodium benzoate from its other products — including Sprite, Fanta, and Oasis — as soon as a satisfactory alternative is discovered. ^ a b c Sigma-Aldrich Co., Sodium benzoate. ^ CFR - Code of Federal Regulations Title 21 ^ Add-on Treatment of Benzoate for Schizophrenia A Randomized, Double-blind, Placebo-Controlled Trial of d-Amino Acid Oxidase Inhibitor December 2013 ^ Digest of Neurology and Psychiatry ^ Mental Health Research Institute Staff Publications, University of Michigan.