Puddings

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). 

Ammonium glycyrrhizinate [53956-04-0] (AG), C42H N02g, is a flavor enhancer derived from Hcorice root. It is approximately 50 times sweeter than sucrose and is often used to enhance sweetness in a wide variety of food products (56). Maltol [118-71 -8] C H O, and ethyl maltol [4940-11-8], CyHgO, are used as flavor enhancers in products such as cake mixes, confections, cookies, ice cream, fmit juices, puddings, and beverages (57). 

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). 

Larch arabinogalactan is approved in 21 CFR 172.610 as a food additive for use as an emulsifier, stabilizer, binder or bodying agent for essential oils and noimutritive sweeteners, flavor bases, nonstandardized dressings, and pudding mixes. It has also been used in the preparation of cosmetic and pharmaceutical dispersions and as an emulsifier in oil—water emulsions (69). Industrially, the main use has been in Hthography as a gum arabic substitute. 

H. K. Pulker, ed.. Wear and Corrosion Resistant Coatings by CUD and PUD, Halstead Press, New York, 1989. 

Other frozen desserts are parfait, souffle, ice cream pudding, punch, and mousse. These are often classified with the sherbets and ices. 

Lighdy derivatized starch acetates are employed in food because of the clarity of their gels and their stabiHty. AppHcations include frozen fmit pies and gravies, baked goods, instant puddings, and pie fillings. Starch acetates are used in textiles as warp sizes and in paper to improve printabiHty, surface strength, and solvent resistance. 

Starch sodium phosphate monoesters [11120-02-8] are prepared by heating mixtures of 10% moisture starch and sodium monohydrogen and dihydrogen phosphates or sodium tripolyphosphate. Starch phosphate monoesters are used primarily in foods, such as pudding starches and with oH-in-water emulsions. 

Miscellaneous. Miscellaneous products having market significance iaclude sour cream, chip dips, milkshake bases, puddings, yogurt and fat-reduced forms of all substitute dairy foods. These products have been formulated from both caseiaates and soybean proteias. 

The radial-inflow turbine is espeeially attraetive when the Reynolds number (Re = pUD/yi) beeomes low enough (Re = 10 — 10 ) that the effieieney of the axial-flow turbine is below that of a radial-inflow turbine, as shown in Figure 8-1. The effeet of speeifie speed (N = and speeifie... 

Polyurethane dispersions (PUD s) are usually high-performance adhesives based on crystalline, hydrophobic polyester polyols, such as hexamethylene adipate, and aliphatic diisocyanates, such as methylene bis(cyclohexyl isocyanate) (H12MDI) or isophorone diisocyanate (IPDI). These PUD s are at the more expensive end of the waterborne adhesive market but provide excellent performance. 

Internal surfactants, i.e., surfactants that are incorporated into the backbone of the polymer, are commonly used in PUD s. These surfactants can be augmented by external surfactants, especially anionic and nonionic surfactants, which are commonly used in emulsion polymerization. Great attention should be paid to the amount and type of surfactant used to stabilize urethane dispersions. Internal or external surfactants for one-component PUD s are usually added at the minimum levels needed to get good stability of the dispersion. Additional amounts beyond this minimum can cause problems with the end use of the PUD adhesive. At best, additional surfactant can cause moisture sensitivity problems with the PUD adhesive, due to the hydrophilic nature of the surfactant. Problems can be caused by excess (or the wrong type of) surfactants in the interphase region of the adhesive, affecting the ability to bond. 

Fig. 5 shows the details of bonding of the two substrates by a waterborne PUD adhesive. The figure shown assumes a PUD adhesive with a fast crystallizing backbone [59]. 

The crystallization kinetics defines the open time of the bond. For automated industrial processes, a fast crystallizing backbone, such as hexamethylene adipate, is often highly desirable. Once the bond line cools, crystallization can occur in less than 2 min. Thus, minimal time is needed to hold or clamp the substrates until fixturing strength is achieved. For specialty or non-automated processes, the PUD backbone might be based on a polyester polyol with slow crystallization kinetics. This gives the adhesive end user additional open time, after the adhesive has been activated, in which to make the bond. The crystallization kinetics for various waterborne dispersions were determined by Dormish and Witowski by following the Shore hardness. Open times of up to 40 min were measured [60]. 

Two-component waterborne urethane dispersions are similar to the one-component PUD s in that a polyurethane dispersion comprises one of the two components. The second component is usually a crosslinker from the following classes of materials (a) polyisocyanates, (b) aziridines, (c) polycarbodiimides, and (d) epoxies. Many of the crosslinkers are not inherently water-soluble or water-dispersible. Therefore, they must be modified with surface active agents themselves, so as to become emulsifiable in water. 

The two-component waterborne urethanes are similar in nature to the one-component waterborne urethanes. In fact, many one-component PUD s may benefit from the addition of a crosslinker. The two-component urethanes may have higher levels of carboxylic acid salt stabilizer built into the backbone than is actually needed to stabilize the urethane in water. As a result, if these two-component urethane dispersions were to be used as one-component adhesives by themselves (without crosslinker), they would show very poor moisture resistance. When these two-component urethane dispersions are used in conjunction with the crosslinkers listed in Fig. 8, the crosslinkers will react with the carboxylic pendant groups built into the urethane, as previously shown in the one-component waterborne urethane section. This accomplishes two tasks at the same time (1) when the crosslinker reacts with the carboxylic acid salt, it eliminates much of the hydrophilicity associated with urethane dispersion, and (2) it crosslinks the dispersion, which imparts solvent and moisture resistance to the urethane adhesive (see phase V in Fig. 5). As a result of crosslinking, the physical properties may be modified. For example, the results may be an increase in tensile properties and a decrease in elongation. Depending upon the level of crosslinking, the dispersion may lose the ability to be repositionable. (Many of the one-component PUD s may... 

Common crosslinkers for hydroxyl-terminated PUD s are water-dispersible isocyanates and melamines. Unlike other crosslinkers, melamine crosslinkers usually have good stability in water. Two major drawbacks are associated with melamine crosslinking. In the first place, the bond must be heated. It will not... 

Once the crosslinker is added, it is important to apply the adhesive and dry off the water. Most of the commonly used crosslinkers will react with water over a period of time and lose effectiveness. In some two-component PUD s, the system may increase in viscosity and even gel, giving the user some idea of when the useful life of the crosslinker is approaching its end. In other instances, no viscosity increases or other visible indications signal that the crosslinker has reached the end of its useful life. The improvements in physical properties, solvent resistance, and water resistance normally provided by a crosslinked PUD adhesive would not be fully realized, in this case. 

Puddel-arbeiter, m. puddler. -bett, n. Pud-delsohle. -eisen, n. puddled iron, -luppe, /. puddle-ball, puddeln, v.t. puddle. 

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