Gelatins, drying

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. 

Add, with stirring, a solution of 6 8 g. of the fiis-diazo ketone in 100 ml. of warm dioxan to a suspension of 7 0 g. of freshly precipitated silver oxide in 250 ml. of water containing 11 g. of sodium thiosulphate at 75°. A brisk evolution of nitrogen occurs after 1 5 hours at 75°, filter the liquid from the black silver residue. Acidify the almost colourless filtrate with nitric acid and extract the gelatinous precipitate with ether. Evaporate the dried ethereal extract the residue of crude decane-1 10-dicarboxylic acid weighs 4 -5 g. and melts at 116-117°. RecrystaUisation from 20 per cent, aqueous acetic acid raises the m.p. to 127-128°. 

Fum ric Acid. Eumaric acid [110-17-8] C H O, is unique in its low solubiUty in cold water and slow rate of solution, making it ideal for use in chilled biscuit leavening systems and for dry pudding mixes and beverage powders. It is also used for gelatin desserts, pie filling, fmit juices, and wine. Eumaric acid is produced by the acid-catalyzed isomerization of maleic acid (8,9) (see Maleic anhydride, maleic acid, and fumaric acid). 

Acesulfame K. Acesulfame K [55589-62-3] C H NO S -K, is an oxathia2iae derivative approximately 200 times as sweet as sucrose at a 3% concentration ia solutioa (70). It is approved for use as a nonnutritive sweeteaer ia 25 couatties (71), and ia the United States has approval for use in chewing gum, confectionery products, dry mixes for beverages, puddings, gelatins, and dairy product analogues, and as a tabletop sweetener (72). 

Complex Coacervation. This process occurs ia aqueous media and is used primarily to encapsulate water-iminiscible Hquids or water-iasoluble soHds (7). In the complex coacervation of gelatin with gum arabic (Eig. 2), a water-iasoluble core material is dispersed to a desired drop size ia a warm gelatin solution. After gum arabic and water are added to this emulsion, pH of the aqueous phase is typically adjusted to pH 4.0—4.5. This causes a Hquid complex coacervate of gelatin, gum arabic, and water to form. When the coacervate adsorbs on the surface of the core material, a Hquid complex coacervate film surrounds the dispersed core material thereby forming embryo microcapsules. The system is cooled, often below 10°C, ia order to gel the Hquid coacervate sheU. Glutaraldehyde is added and allowed to chemically cross-link the capsule sheU. After treatment with glutaraldehyde, the capsules are either coated onto a substrate or dried to a free-flow powder. 

Spray Drying. Spray-dry encapsulation processes (Fig. 7) consist of spraying an intimate mixture of core and shell material into a heated chamber where rapid desolvation occurs to thereby produce microcapsules (24,25). The first step in such processes is to form a concentrated solution of the carrier or shell material in the solvent from which spray drying is to be done. Any water- or solvent-soluble film-forming shell material can, in principle, be used. Water-soluble polymers such as gum arable, modified starch, and hydrolyzed gelatin are used most often. Solutions of these shell materials at 50 wt % soHds have sufficiently low viscosities that they stiU can be atomized without difficulty. It is not unusual to blend gum arable and modified starch with maltodextrins, sucrose, or sorbitol. 

Liquid food ingredients encapsulated are typically oil-soluble flavors, spices (see Flavors and spices), and vitamins (qv). Even food oils and fats are encapsulated (63). These core materials normally are encapsulated with a water-soluble shell material appHed by spray drying from water, but fat shell formulations are used occasionally. Preferred water-soluble shell materials are gum arabic, modified starch, or blends of these polymers with maltodextrins. Vitamins are encapsulated with 2ero bloom strength gelatin by spray drying. 

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