Gelatin finings

Coating the droplets e.g, starch acacia, silica, gelatin finely divided talc, and... 

Among wine polysaccharides, mannoproteins play an important role in protein haze stabilisation (Waters et al. 1994 Dupin et al. 2000). Gelatin fining of a wine phenolic extract in wine-like solution resulted in a much higher precipitation rate than when the same treatment was applied on the original wine. After addition of wine polysaccharides at the concentration normally encountered in wines, precipitation was reduced back to the level measured in wine, confirming the stabilizing effect of polysaccharides (Cheynier et al. 2006). 

The success of gelatin fining essentially depends on the temperature of the juice. At low temperature (less than 7°C) the gelatin does not flocculate completely (so hazes may develop later). The process should therefore be carried out at temperatures around 15°C. 

To the remainder of the gelatin solution, add 0 5 to o 8 g. of finely powdered commercial trypsin and incubate at 40 . Carry out the formaldehyde titration on 25 ml. samples at intervals as above. 

Benzylatnine. Warm an alcoholic suspension of 118-5 g. of finely-powdered benzyl phthalimide with 25 g. of 100 per cent, hydrazine hydrate (CAUTION corrosive liquid) a white, gelatinous precipitate is produced rapidly. Decompose the latter (when its formation appears complete) by heating with excess of hydrochloric acid on a steam bath. Collect the phthalyl hydrazide which separates by suction filtration, and wash it with a little water. Concentrate the filtrate by distillation to remove alcohol, cool, filter from the small amount of precipitated phthalyl hydrazide, render alkaline with excess of sodium hydroxide solution, and extract the liberated benzylamine with ether. Dry the ethereal solution with potassium hydroxide pellets, remove the solvent (compare Fig. //, 13, 4) on a water bath and finally distil the residue. Collect the benzylamine at 185-187° the 3ueld is 50 g. 

Minerals, particularly Bentonite, ate used to remove proteins that tend to cause haze in white wines. The natural tannin of ted wines usually removes unstable proteins from them. Excess tannin and related phenols can be removed and haze from them prevented by addition of proteins or adsorbents such as polyvinylpyttohdone. Addition of protein such as gelatin along with tannic acid can even be used to remove other proteins from white wines. Egg whites or albumen ate often used to fine ted wines. Casein can be used for either process, because it becomes insoluble in acidic solutions like wines. 

Gelatin stmctures have been studied with the aid of an electron microscope (23). The stmcture of the gel is a combination of fine and coarse interchain networks the ratio depends on the temperature during the polymer-polymer and polymer-solvent interaction lea ding to bond formation. The rigidity of the gel is approximately proportional to the square of the gelatin concentration. Crystallites, indicated by x-ray diffraction pattern, are beUeved to be at the junctions of the polypeptide chains (24). 

Filtration by suction is rarely necessary with gelatinous and some finely divided precipitates, the suction will draw the particles into the pores of the paper, and the speed of filtration will actually be reduced rather than increased. 

A process is described for the production of finely divided gelatin-free dispersions of photographic additives in an aqueous medium in the presence of a high-boiling solvent and a phosphorus-containing surfactant. Thus, a yellow... 

Another use for sulfuric acid is in water treatment. Aluminum sulfate, which is produced by treating sulfuric acid with aluminum oxide, is a top-50 industrial chemical because of its widespread use as a coagulant. Addition of AI2 (804)3 Ca(OH)2 generates a gelatinous precipitate of aluminum hydroxide mixed with calcium sulfate AI2 (804)3 ) (OH)2 (tJ ( ) A Al (OH)3 (. ) + CaS04(.S ) The gel traps finely suspended... 

Gelatine explosives, initiated by commercial detonators, will normally fire at the low velocity of detonation initially, although this may well build up quite quickly into the high velocity. For some applications a high velocity of detonation is essential. This can be ensured by the addition of barium sulphate, or other material with density exceeding 2-8, in a fine form. Such additives have the property of ensuring rapid transition to the high velocity of detonation. This is, for example, of particular importance when the explosive is to be fired under a hydrostatic head, as in submarine work. 

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