Water solubility fatty acids

In milk plasma, fat may be present as extremely small globules, water-soluble fatty acids and other lipids, water-dispersible lipids, or lipoprotein particles. The amount is small, 0.02-0.03%. Obviously, most of the lipid is TG in the core of the globules. 

Ekrami, H., A. Kennedy, and W. Shen. 1995. Water-soluble fatty acid derivatives as acylating agents for reversible lipidization of polypeptides. FEBS Lett 371 283. 

Water soluble fatty acids, sugars, amino acids — — < 1 1-5... 

Free fatty acids are not used as surfactants, due to their low solubility in water. However water-soluble fatty acid salts show good water affinity and are widely used, especially the alkaline ones and those resulting from neutralization with short-chain amines (ethanol amine, diethanol amine, triethanol amine). 

The Reichert value is the number of millilitres of O.IN aqueous sodium hydroxide solution required to neutralize steam volatile water soluble fatty acids distilled from 5g of an... 

Wherever possible, the soaps and surfactants were added to the natural rubber latex as dilute aqueous solutions. The cases where this was not possible were (a) ethylene oxide-fatty alcohol condensates of low ethylene oxide fatty alcohol mole ratio, and (b) sparingly-soluble fatty-acid soaps such as lithium laurate and calcium soaps. The former were added as pastes with water, the latter as dry powders. In all cases, the latex samples were allowed to mature for about three days at room temperature before their mechanical stabilities were determined. This allowed some opportunity for the attainment of adsorption equilibrium. 

Sulfonic acids and sulfonate salts contain the -S03H and -SO) groups, respectively, attached to a hydrocarbon moiety. The structural formulas of benzene sulfonic acids and of sodium 1 -(p-sulfophenyl)decane, a biodegradable detergent surfactant, are shown in Figure 1.19. The common sulfonic acids are water-soluble strong acids that lose virtually all ionizable H+ in aqueous solution. They are used commercially to hydrolyze fat and oil esters to produce fatty acids and glycerol used in chemical synthesis. 

Another consideration is the amount of sample (in mg) required for NMR. Because it is the concentration (mM) of molecules that determines the signal strength in NMR, as the molecular size increases the desired concentration of around 1 mM corresponds to larger and larger amounts of protein (Table 12.1). For a small protein (e.g., RNase at 12.6 kD) the sample size is around 6 mg. Talk to a biochemist or molecular biologist if you think this is a small amount of pure protein Now move to chymotrypsin (22.6 kD), which would require 11 mg of pure protein to be soluble and monomeric in 0.5 mL of water. For fatty acid synthase, with 20,000 amino acid residues and 21 polypeptide chains, we would need to dissolve 1.15 g of protein in our 0.5 mL sample volume, clearly an impossibility. 

As previously mentioned, tocopherols/tocotrienols may be added to foods for the stabilization of their polyunsaturated fatty acids. Chemical conditions and the physical state of the food to be stabilized have a major influence on lipid oxidation and antioxidant reactions. The number of possible reaction routes and stabilizing and destabilizing factors is enormous (e.g., Pokorny, 1987 Warner, 1997 Frankel, 1998). In foods, tocopherols can be regenerated from their tocopheroxyl radicals by reducing compounds such as ascorbic acid. Regeneration is possible only if the lipid-soluble tocopheroxyl radical and the water-soluble ascorbic acid are close enough to be able to react with each other, e.g., in emulsion. Thus, the interfacial region between lipid and water phases is important for the antioxidant action of tocopherols and tocotrienols (Frankel, 1998). 

The concentration of butanoic acid in milk fat is the principle of the widely used criterion for the detection and quantitation of adulteration of butter with other fats, i.e. Reichert Meissl and Polenski numbers, which are measures of the volatile water-soluble and volatile water-insoluble fatty acids, respectively. 

Butyric acid is a thick, sour liquid, which boils at 162°, and is miscible with water in all proportions. Addition of calcium chloride to an aqueous solution of the acid causes the latter to separate as an oil. The other soluble fatty acids, with the exception of formic and acetic acids, act in this way. The salts of butyric acid are soluble in water. Calcium butyrate, (C4H702)2Ca.H20, is more soluble in cold than in hot water. It is precipitated, in part, when a cold saturated solution of the salt is heated to boiling. The calcium salt of isobutyric acid (C4H702)2Ca.5H20, is more soluble in hot than in cold water. 

Niestroj, A. Use of RP-TLC to investigate the solubility in water of fatty acids, hydroxyl fatty acids and their esters. J. Planar Chromatogr. Mod. TLC 2006, 19 (3), 208 211. 

In the beginning of past century, liquid soaps were prepared by dissolving potassium salt of coco fatty acids in glycerin [69]. With time, glycerin has been replaced by water, and fatty acid salts have been replaced by milder, more soluble, synthetic surfactants in liquid products. 

Health aspects, acute toxicity. Propionic acid is absorbed by the digestive tract on account of its good water-solubility. Propionic acid is metabolised in the human body in a manner similar to that of fatty adds. Therefore the decomposition products of propionic acid in the tissue of mammals are CO2 and H2O. Even after the administration of large doses in the diet, propionic acid is excreted in the urine and there is no risk of accumulation in the human body. High and extensive feed may lead to hyperplasia and severe inflammatory lesions in the forestomach mucosa of rats. Under normal circumstances propionic acid was not observed to have any effect on the mucosa (Harrison, 1991 Bueld and Netter, 1993). 

The solubility characteristics of sodium acyl isethionates allow them to be used in synthetic detergent (syndet) bars. Complex blends of an isethionate and various soaps, free fatty acids, and small amounts of other surfactants reportedly are essentially nonirritant skin cleansers (45). As a rule, the more detersive surfactants, for example, alkyl sulfates, a-olefin sulfonates, and alkylaryl sulfonates, are used in limited amounts in skin cleansers. Most skin cleansers are compounded to leave an emollient residue on the skin after rinsing with water. Free fatty acids, alkyl betaines, and some compatible cationic or quaternary compounds have been found to be especially useful. A mildly acidic environment on the skin helps control the growth of resident microbial species. Detergent-based skin cleansers can be formulated with abrasives to remove scaly or hard-to-remove materials from the skin. 

The salts of mono- and diesters of phosphoric acid with fatty alcohol or their ethoxylates are anionic - surfactants. The water solubility and acid strength of such partial esters decrease with increasing chainlength. However, the sodium salts have good solubility. They are resistant to water hardness and to - hydrolysis, especially in alkaline media. They have good wetting and emulsifying properties. 

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