Effect of ascorbic acid

Iron Absorption. A very important effect of ascorbic acid is the enhancement of absorption of nonheme iron from foods. Ascorbic acid also enhances the reduction of ferric iron to ferrous iron. This is important both in increasing iron absorption and in its function in many hydroxylation reactions (140,141). In addition, ascorbic acid is involved in iron metaboHsm. It serves to transfer iron to the Hver and to incorporate it into ferritin. 

FIGURE 18.30 The physiological effects of ascorbic acid (vitamin C) are the result of its action as a reducing agent. A two-electron oxidation of ascorbic acid yields dehy-droascorbic acid. 

Table II. Effect of Ascorbic Acid on the Color of Applesauce Stored at 75°F in Various Types of Cans0...

Figure L Effect of ascorbic acid on NDELA formation.

Choi, M.H., Kim, G.H., and Lee, H.S., Effects of ascorbic acid retention on juice color and pigment stability in blood orange Citrus sinensis) juice during refrigerated storage, Food Res. Int, 35, 753, 2002. 

Meister A. (1992). On the antioxidant effects of ascorbic acid and glutathione. Biochem. Pharmacol. 44, 1905-1915. 

Malo, J.L., Cartier, A., Pineau, L., Archeveque, J., Ghezzo, H. and Martin, R.R. (1986). Lack of acute effects of ascorbic acid on spirometry and airway responsiveness to histamine in subjects with asthma. J. Allergy Clin. Immunol. 78, 1153-1158. 

Rababah, TM, Ereifej, KI and Howard, L. 2005. Effect of ascorbic acid and dehydration on concentrations of total phenolics, antioxidant capacity, anthocyanins, and color in fruits. J Agric Food Chem 53(ll) 4444-4447. 

Tominaga et al. [682,683] studied the effect of ascorbic acid on the response of these metals in seawater obtained by graphite-furnace atomic absorption spectrometry from standpoint of variation of peak times and the sensitivity. Matrix interferences from seawater in the determination of lead, magnesium, vanadium, and molybdenum were suppressed by addition of 10% (w/v) ascorbic acid solution to the sample in the furnace. Matrix effects on the determination of cobalt and copper could not be removed in this way. These workers propose a direct method for the determination of lead, manganese, vanadium, and molybdenum in seawater. 

Recently, Carr and Frei reviewed studies on the antioxidant and prooxidant effects of ascorbic acid [8]. These authors pointed out that a highly controversial work by Podmore and coworkers [71] who found that the prooxidant effect of ascorbic acid supplementation to healthy volunteers is much questionable. These authors demonstrated that of the 44 in vivo studies, 38 showed the antioxidant effect of ascorbic acid, 14 showed no change, and only six showed the enhancement of oxidative damage after ascorbate supplementation. It was concluded that ascorbic acid is an antioxidant in biological fluids, animals, and humans, both with and without iron supplementation. 

Peng, Z., Duncan, B., Pocock, K. F., and Sefton, M. A. (1998). The effect of ascorbic acid on oxidative browning of white wines and model wines. Aust. ]. Grape Wine Res. 4,127-135. 

Hermel, M., Heckelen, A., Kirchhof, B., Schrage, N.F. Inhibitory effect of ascorbic acid on human retinal pigment epithelial cell proliferation compared to cytostatic drugs-influence of histamine. Inflamm Res 50(Suppl 2), S93-S95... 

In its biochemical functions, ascorbic acid acts as a regulator in tissue respiration and tends to serve as an antioxidant in vitro by reducing oxidizing chemicals. The effectiveness of ascorbic acid as an antioxidant when added to various processed food products, such as meats, is described in entry on Antioxidants. In plant tissues, the related glutathione system of oxidation and reduction is fairly widely distributed and there is evidence that election transfer reactions involving ascorbic acid are characteristic of animal systems. Peroxidase systems also may involve reactions with ascorbic acid In plants, either of two copper-protein enzymes are commonly involved in the oxidation of ascorbic acid. 

Chen, T.S.. R.G, Cooper "Thermal Destruction of Folacin Effect of Ascorbic Acid. 

Kamm, J.J, et al. Protective Effect of Ascorbic Acid on Hepatotoxicity Caused by Sodium Nitrite plus Aminopyrine, Proc., Nat. Acad. Sci., 70, 74 (1973). 

Sandnes, K, Ulgenes, Y., Braekkan, O.R. and Utne, F. (1984). The effect of ascorbic acid supplement in broodstock feed on reproduction of rainbow trout (Salmo gairdneri). Aquaculture 43,167-177. 

D12. Dwenger, A., Funck, M., Lueken, B., Schweitzer, G., and Lehmann, U., Effect of ascorbic acid on neutrophil functions and hypoxanthine-xanthine oxidase-generated, oxygen derived radicals. Eur. J. Clin. Chem. Clin. Biochem. 30, 187-191 (1992). 

A Golan-Goldhirsh, DT Osuga, AO Chen, JR Whitaker. Effect of ascorbic acid and copper on proteins. In VT D Souza, J Feder, eds. The Bioorganic Chemistry of Enzymatic Catalysis An Eiomage to Myron L. Bender. Boca Raton, FL CRC Press, 1992, pp 61-76. 

There have been several epidemiological and several case reports inversely relating ascorbic acid intake from food to human cancer mortality. These studies are interesting, but may be confounded with the fact that the same ascorbic acid containing foods, namely fruits and vegetables, also contain large amounts of vitamin A and fiber. Both vitamin A and fiber have been inversely related to human cancer mortality and have been shown to inhibit several types of chemically-induced carcinogenesis in animals. Therefore, the possible anti cancer effect of ascorbic acid may be due to other factors. 

Okorukwu, O.N. and Vercruysse, K.P., Effects of ascorbic acid and analogs on the activity of testicular hyaluronidase and hyaluronan lyase on hyaluronan, J. Enzyme Inhib. Med. Chem., 18, 377, 2003. 

Figure 3 shows the dramatic effect of ascorbic acid deprivation on... 

At 30°C in the absence of Arg, the ferrous-oxi complex transforms very slowly to the ferric state. In the presence of substrate and H4B, a new species with the 12-nm shifted Sorey band is detected. A decay of this species is accompanied by the formation ofN -hydroxy-L-arginine. Because the presence of HUB is necessary for these reactions, the main function of this compound is to be a reducing agent. This suggestion is supported by experiments on the stabilizing effect of ascorbic acid on the chemical stabilization of tetrahydropterin in the endothelial nitric oxide synthesis (Heller et al., 2001). At the same time, a significant increase in the half lifetime of H4B in solution is demonstrated. As is shown (Wei et al., 2001), a ferrous-dioxy intermediate in iNOS forms for 53 s 1 and then is transformed to the [S-Fe(IV)=0] state. The rate of the [S-Fe(IV)=0] decay is equal to the rate ofH4B radical formation and the rate of Arg hydroxylation. In contrast,... 

In a series of five studies of 14 days each, the effects of ascorbic acid on manganese utilization were investigated. The usual basal diet was modified to lower the ascorbic acid content by substituting apple juice for the usually-fed orange and tomato juices. 

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