Acid, acetic lactic

Lipids Fats Waxes 1 Oils 1 Hydrocarbons J r RCH2OH RCOOH RCH2CH2COOH + CH2OHCHOHCH2OH shorter ohain aoids fatty acids giyceroi j pQj-jj 1, RH CO2, CH4, aliphatic acids, acetic, lactic, citric, glycolic, malic, palmitic, stearic, oleic acids, carbohydrates, hydrocarbons... 

Physical properties. All are colourless crystalline solids except formic acid, acetic acid (m.p. 18 when glacial) and lactic acid (m.p. 18°, usually a syrup). Formic acid (b.p. loo ") and acetic acid (b.p. 118 ) are the only members which are readily volatile lactic acid can be distilled only under reduced pressure. Formic and acetic acids have characteristic pungent odours cinnamic acid has a faint, pleasant and characteristic odour. 

Formic acid Acetic acid Stearic acid Lactic acid... 

This difference in behavior for acetic acid in pure water versus water buffered at pH = 7 0 has some important practical consequences Biochemists usually do not talk about acetic acid (or lactic acid or salicylic acid etc) They talk about acetate (and lac tate and salicylate) Why Its because biochemists are concerned with carboxylic acids as they exist in di lute aqueous solution at what is called biological pH Biological fluids are naturally buffered The pH of blood for example is maintained at 7 2 and at this pH carboxylic acids are almost entirely converted to their carboxylate anions... 

Hydroxyl tion. Commercial lecithin can be hydroxylated at the unsaturated fatty acid chains by treatment with concentrated hydrogen peroxide and acids like lactic or acetic acid. 

Numerous organic acids iu coffee iuclude acids of metaboHc origin, eg, acetic lactic, citric, malic, and oxaUc free quiuic acid [77-95-2], and various chlorogenic acid (CGA) isomers that appear to be species specific. 

Resistance to corrosion of electroless nickel, both as-deposited and, in most cases, after heating to 750°C, is listed by Metzger for about 80 chemicals and other products. Resistance was generally satisfactory, with attack at a rate below 13 /im/year. The only substances causing faster attack were acetic acid, ammonium hydroxide or phosphate, aerated ammonium sulphate, benzyl chloride, boric acid, fluorophosphoric acid, hydrochloric acid, aerated lactic acid, aerated lemon juice, sodium cyanide and sulphuric acid. 

Which would you expect to be a stronger acid, the lactic acid found in tired muscles or acetic acid Explain. 

The sugars in fruits such as grapes are feimented by yeasts to produce wines. In winemaking, lactic acid bacteria convert malic acid into lactic acid in malolactic fermentation in fruits with high acidity. Acetobacter and Gluconobacter oxidise ethanol in wine to acetic acid (vinegar). 

Lactic acid Acetic acid reducing suga... 

The pectin/sucrose gels were characterized as follows (amounts per lOOg gel) 0.3 g AUA, 65% soluble solid substance, 0.01 mol sodium acetate / lactic acid buffer, pH 3.0 (20°C). The metal ions were added as combinations of chlorides according to a mixture design with constant amount of chloride ions (2.5 mmol / lOOg gel). Thus the total amount of metal ions... 

In Figure 34.7b, the relative selectivity to byproducts such as EG and organic acids is shown (primarily acetic, lactic and glyceric acids). Not all carbon supports are equivalent, as there are a wide variety of source materials that are used in their production. Note that the highest acid selectivity is shown with the catalyst based on a graphitic carbon and on a carbon support first treated with titania. 

Precipitation of Fe(IIl) compounds from acid solutions as the pH increases above 2.2 is a particular problem. Complexing agents that have been used include 5-sulfosalicylic acid and citric acid (136) dihydroxymaleic acid (137) ethylenediaminetetraacetic acid (138) lactic acid (138) blends of hydroxylamine hydrochloride, citric acid, and glucono-delta-lactone (139) nitriloacetic acid blends of citric acid and acetic acid lactic acid and gluconic acid (140). 

Different organic acids, primarily lactic acid, have been successfully used for decontamination of whole livestock carcasses, and the application of different organic acids used for decontamination has also been tested in the fruit and vegetable industry. Organic acids other than lactic acid that are known to have bactericidal effects are acetic, benzoic, citric, malic, propanoic, sorbic, succinic and tartaric acids (Betts and Everis 2005). The antimicrobial action is due to a reduction in the pH in the bacterial environment, disruption of membrane transport, anion accumulation or a reduction in the internal pH in the cell (Busta et al., 2001). Many fruits contain naturally occurring organic acids. Nevertheless, some strains, for example E. coli 0157, are adapted to an acidic environment. Its survival, in combination with its low infective dose, makes it a health hazard for humans. 

The application of near-IR spectroscopy for real-time monitoring of glucose, lactic acid, acetic acid and biomass in liquid cultures of microorganisms of the genera Lactobacillus and Staphylococcus has been recently published [76]. The NIR spectrum acquired by the optical-fibre probe immersed in the culture is exploited using a partial least squares (PLS) calibration step, a classical method for IR techniques. 

Figure 4.7 Anion exchange separation of carboxylic acids in red wine. Column, Shodex C811, 100 cm x 7.6 mm i.d. eluent, 3 mM perchloric acid flow rate, 0.9 ml min-1 temperature, 60 °C detection, reaction detection using chloro-phenol red at 430 nm. Peaks 1, citric acid 2, tartaric acid 3, malic acid 4, succinic acid 5, lactic acid 6, formic acid and 1, acetic acid.

Morita T, Takeda K, Okumura K Evaluation of clastogenicity of formic acid, acetic acid and lactic acid on cultured mammalian cells. Mutat Rer240(3) 195-202, 1990... 

Fig. 8.6. HPLC chromatogram of a first-cut silage juice using a Spherisorb Cg 5p column. Identity a, formic acid b, lactic acid c, acetic acid d, propionic acid e, n-butyric acid. The peak at 17.34 min is 50 pg mM mesaconic acid added as a possible internal standard, which proved unsuitable because of an unknown peak eluting at 16.78 min obtained using silage juioe without added internal standard.

In carboxylic acid solutions, the corrosion rate increases with acid concentration (acetic, lactic) however, in oxalic and tartaric acid solutions, the dissolution of metal is associated with the formation of passive lead salt layer [341]. 

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