Water-binding agent

Enol ether 13 is prepared from butanal 12 by acetalization with alcohol PMBOH 35. The resulting acetal 40 is subjected to elimination with phosphinic acid 36. Acetalization proceeds via nucleophilic attack of the alcohol on the protonated aldehyde 37, dehydratization of the hemiacetal 38 and further nucleophilic attack on the carbenium ion 39. Since all steps are reversible, the created water has to be removed to achieve quantitative turnover. This is carried out by the use of water binding agents or solvents (dry Na2S04, CaCl2, orthoesters) or azeotropic distillation. 

Formulation. Several patents have been issued covering low-fat spreads formulation and processing indicating that critical process control and/or significant levels of water binding agents are required (91, 92, 97, 98). 

The preparation of dialkyl oxalates by oxidative carbonylation of alcohols was first described by Fenton et al. in the early 1970s [72-74]. For example, the reaction can be carried out at a temperature around 125 °C and a pressure of about 70 bar in the presence of PdCl2 and iron or copper salts. Water is formed as a by-product and has to be removed from the reaction mixture by the addition of water-binding agents such as trialkyl orthoformates. Instead of oxygen benzo-quinone can also be used for the reoxidation of the catalyst system. Ammonia or amines seem to have a positive influence on selectivity and efficiency of the reae-tion. For some more examples, cf. [77-80, 117]. Mechanistic studies give some indication that alkoxycarbonylpalladium species occur as intermediates [52, 75, 76] (eq. (12)). 

A further method of preparing methyl esters was provided by Lorette and Brown Jr.804 who used acetone dimethyl acetal as water-binding agent ... 

Solvent-free two-pack systems require liquid reaction components and are normally based on MDI and its homologues. In contrast to solvent-containing paints, pigmented solvent-free two-pack systems require the use of water-binding agents (e.g., zeolites) to obtain thick, bubble-free coatings. 

The literature in this field is replete with a wide variety of model systems using for example cellulose, or silica, or amylopectin as solid supports, extruded mixtures of polyunsaturated fatty acids and esters with pure proteins, in the presence of humectants (to control moisture content) such as glycerol, or dextran as water-binding agent. Studies with such model systems are inherently problematic, because they do not simulate real foods where oxidation is naturally inhibited by the separation of lipids from catalysts in different cellular compartments. There is a serious lack of knowledge on the interactions of oxidized lipids and proteins in complex foods. 

Water-binding agents. Preparations of protein hydrolysates containing amino acids and peptides obtained from marine raw material, particularly fish fractions, presently represent a very interesting area of research. As with the above-mentioned extracts, these preparations may find use in foods, particularly seafoods, because of their typical fish or shellfish taste. In addition, the peptides may have special effects when added to frozen fish, retaining some of the muscle juiciness and perhaps also yielding a better taste characteristic of the frozen fish. 

C. is preferably used in nonfood and pharmaceutical applications as water-binding agent (tooth pastes, emulsions). 

Straight g. is used as is in - food additives, mostly as thickener and water-binding agent. Derivatives are not approved for food uses. G. is used in ice creams, salad dressings, cheese, jams and jellies, milk products and soups. There are also some applications in caimed pet food and in cattle feed. 

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