Fatty acid mixture crystallization using

Mixtures of fatty acid salts are used as soaps. Sodium palmitate—stearate mixtures are solid at room temperature, and the corresponding potassium salt mixtures are fluid, although only potassium palmitate has been crystallized at room temperature. Metal carboxylates hydrolyze in water and release hydroxyl ions on the skin s surface. Soaps with fewer than 12 carbon atoms therefore bite. This happens with nonpurified soaps as obtained from fats containing fractions. Longer alkyl chains produce soft soaps, since they are not soluble as monomers in water and the surface liquids of the skin (sebum, sweat). Sulfonates, on the other hand, do not show such differences because they are always present as fully dissociated salts at physiological pH values and produce no hydroxyl ions. Allergic reactions to commercial soaps are mostly not caused by the fatty acids but by additives, such as perfumes. 

Crystallization of a Fatty Acid Mixture Using Spray Evaporation of Highly Volatile Solvents... 

Most naturally occurring lipids are not chiral (parafiins, oleic acid, palmitin, etc.) or are mixtures of compounds which are difficult to separate (lecithin, asymmetric glycerols). A few chiral fatty acids have been used, like methylated (Figure 4.4) [8] and alicylic (Figure 4.5) [9] adds. The chiral centers of fatty acids are often comformational flexible and they are not connected with large dipole moments. Also, the chemical modification of the chiral centers is more difficult than for amino acids and sugars. Thus, chiral lipids have only limited use in liquid crystal research. 

Traditional chemical methods are currently used in the characterization of fatty acids neutralization values permit the calculation of the mean molecular weight and a series of values (for instance, iodine, thiocyanogen, and hydrogenation values) for determining the degree of unsaturation. A complete analysis of fatty acid mixtures would nevertheless require the qualitative and quantitative detection of all the fatty acids (Fontell et al., 1960). Such methods as crystallization of salts and bromine adduct formation have been used to some extent. Nowadays, less conventional methods have found wide... 

Distillation By-Products. Of the CTO distiHation by-products, ie, pitch, heads, and DistiHed TaH Oil (DTO), only the last, a unique mixture of rosin and fatty acids, has significant commercial value. Pitch and heads are used as fuel the former has a fuel value of 41,800 kj/kg. TaH oil heads have outstanding solvent properties, but also have a bad odor, which is hard to remove. They contain a relatively high fraction of palmitic acid which can be recovered by crystallization. 

The recovery of phytosterols or their concentration is the third step in their isolation. Methyl esters of fatty acids are distilled to raise the phytosterol content up to 50% by weight. Molecular distillation can be used for phytosterols. Phytosterol concentrates are used as raw materials for steroid drug preparation via microbial fermentation, in which the pure form of phytosterols are not necessary. The final recovery of phytosterols can be achieved by crystallization (physical), solvent extraction (chemical), or crystallization with additives via adduct formation and separation (physicochemical). Organic solvents or solvent mixtures composed of low- and high-polarity solvents and water are used for crystallization of phytosterols... 

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