Hydrocolloids alginate

Substances that are used in wound dressings include hydrogels, hydrocolloids, alginates, and polyurethane foams. Medicaments that they contain include wool wax alcohols (amerchol, cetearyl alcohol, propylene glycol), plant resins/ethereal oils (balsam of Peru, colophony, fragrance mix, propolis), and topical antibiotics. 

It is interesting to note that much of the research that led to the development of modem wound-management products was concentrated on the moist-healing principle, and in the 1980 and 1990s many moist-heaUng products, such as hydrocolloids, alginates, polyurethane foams, and hydrogels, were developed and launched in the... 

Sodium alginate (algin) is one of the most widely used hydrocolloids for ice cream. It is supplied in several viscosity types. The lower viscosity material is recommended in order to prevent thick mixes. It is used at a level of 0.15 to 0.25%. It is added to mix at higher temperatures in order to minimize precipitation by calcium salts present in milk products. Sodium alginate is sensitive to high acidities often developed in some mixes and causes thickening. 

Most of the hydrocolloids listed for ice cream may be used in ices and sherbets. Gelatin is used a great deal. However, it makes overrun difficult to control and consequently it is used in conjunction with other hydrocolloids. A 225 Bloom gelatin is used at 0.4 to 0.5%. Sodium alginate is affected by acid and calcium salts and is not often used. Propylene glycol alginate is more resistant in this respect and is used at levels of 0.15 to 0.25%. Carrageenin is used in many blends. 

Cellulose gum, Irish moss extract, and propylene glycol alginate are the hydrocolloids most of en used in this application at levels of between 0.25 and 1%, depending on the fruit-sugar ratio and the type of fruit. 

The hydrocolloids used stabilize this type of icing by their ability to form a gel or a highly viscous solution. Agar-agar, locust bean gum, sodium alginate (combined with a buffer and calcium salt), Irish moss extract, pectin, and karaya gum are hydrocolloids used. The finished icing may contain from 0.1 to 0.5% hydrocolloids. 

W e know of many examples of the effect of impurities of crystallization. In many cases impurities will completely inhibit (2-4) nucleus formation. Reading the literature on this subject impresses one with the frequent occurrence of hydrocolloids as crystal modifiers, particularly where sugar or water is the material being crystallized. The use of gelatin, locust bean gum, or sodium alginate in ice cream is just one example of many practical applications of hydrocolloids in crystal modification. 

Alginates, unique hydrocolloids extracted from selected species of brown seaweed (kelp), interact with calcium ions to produce thermally stable gels. Using this interaction, flavor oils may be encapsulated or entrapped in the algin gel matrix. Encapsulation is accomplished at ambient temperatures. Products may be used "as is" (wet) or subsequently dried. This technique offers the potential for novel flavor effects, flavor protection, and new food products. 

Milk fat and milk solids-not-fat (MSNF) are most commonly obtained from cream and condensed skim milk, but may also be obtained from a combination of fluid milk, condensed whole milk, frozen cream, frozen condensed milk, nonfat dry milk, dry whole milk, and butter. Sweeteners used in the mix normally include a combination of liquid or dry sucrose, corn sweetener, high-fructose corn sweetener, and corn syrup solids. Ice cream stabilizers are formulated to contain one or more polysaccharide hydrocolloids, e.g., carboxymethyl cellulose, locust bean gum, carageenin, alginate, and other gums. Ice cream emulsifiers normally contain monoglycerides and diglycerides of palmitic and stearic... 

Stabilizers and Thickeners. Many food products receive their textural properties from a group of compounds known as hydrocolloids. Hydrocolloids fall into Iwo classes polysaccharides and proteins. They include loeust bean gum. guar gum, gum arabic. carrageenan, xanthan gum. cellulose. agar, starch, pectin, alginates, and gelatin. See also Stablizer. 

Any colloids derived from marine sources. Examples include the hydrophilic colloids (hydrocolloids) derived from various seaweeds, such as algin, and colloids derived from marine animals, such as chitin. See also Seaweed Colloids. 

Polysaccharides hydrocolloids (Modified) starches, maltodextrins, P-cyclodextrins, alginate, gum arabic, pectin/polypectate, carrageenan, agarose... 

King, A.H. (1983). Brown seaweeds extracts (alginates). In M. Glicksman (ed). Food Hydrocolloids. Boca Raton, FL, pp. 115-188. 

Peniche C., Howland I., Carrillo O., Zaldivar C., and Arguelles-Monal W. (2004). Formation and stability of shark liver oil loaded chitosan/calcium alginate eapsules. Food Hydrocolloids 18, 865-871. 

Neiser, S., Draget, K. I., and Smidsrod, O. 1998. Gel formation in heat treated bovine serum albumin-sodium alginate systems. Food Hydrocolloids 12 127-132. 

Rao, M. A. and Cooley, H. J. 1995. Rates of structure development during gelation and softening of high-methoxyl pectin-sodium alginate-fructose mixtures. Food Hydrocolloids 9 229-235. 

In the area of controlled release, the preparation of indomethacin sustained-release microparticles from alginic acid (alginate)-gelatin hydrocolloid coacervate systems has been investigated. In addition, as controlled-release systems for liposome-associated macromolecules, microspheres have been produced encapsulating liposomes coated with alginic... 

Antonov, Y.A., Lashko, N.P., Glotova, Y.K., Malovikova, A. and Markovich, O. 1996. Effect of the structural features of pectins and alginates on their thermodynamic compatibility with gelatin in aqueous media, Food Hydrocolloids, 10(1) 1—9. 

This usually means heating followed by cooling. For some hydrocolloids (such as alginate) the presence of chelating agents (divalent ions from salts) can generate the gel in cold conditions. 

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