Glycerol, from sorbitol

Several polyols (i.e. molecules displaying multiple hydroxyl groups) have found application as polypeptide stabilizing agents. Polyols include substances such as glycerol, mannitol, sorbitol and PEG, as well as inositol (Table 6.9 and Figure 6.22). A subset of polyols is the carbohydrates, which are listed separately (and thus somewhat artificially) from polyols in Table 6.9. Various polyols have been found to stabilize proteins in solution directly, and carbohydrates in particular are also often added to biopharmaceutical products prior to freeze-drying in order to provide physical bulk to the freeze-dried cake. 

Reductions catalyzed by glycerol dehydrogenase, sorbitol dehydrogenase, mannitol dehydrogenase, and aldose reductases formation of polyols from carbohydrates. 

Glycerol can be obtained from sorbitol and xylitol by means of hydro-genolysis on nickel (163-165). 

In that most foodstuffs contain proteins, the formation of protein-surfactant complexes plays a direct role in 2. and an indirect role in 1. and 3., particularly with respect to their adsorption at oil-water interfaces and distribution between the phases. The surfactants used in foodstuffs are necessarily controlled, and permitted food emulsifiers are esters (or partial esters) formed from fatty acids (from animal and vegetable sources) with polyvalent alcohols such as glycerol, propylene glycerol, or sorbitol. 

Common antifogging agents are fatty acid esters such as glycerol and sorbitol stearate, fatty alcohols, and ethyloxylates of nonyl phenols. Antifogging agents are incorporated in the resin in levels ranging from 0.5 to 4%. Factors involved in the selection and use of these additives include polymer type, thickness of the structure... 

Starch can be destructurized using extrusion technologies in specific conditions. Sufficient work, heat and time have to be applied to a cereal-based starch product in the presence of plasticizers to destructurize it. The best plasticizer for starch is water in quantities lower than 45%. Other plasticizers are glycols such as glycerol and sorbitol. Whereas thermoplastic starch can contain a certain amount of granular residue and a few Maltese crosses can be detected in polarized light microscopy, destructurized starch is substantially free from those features. 

The elasticity enhancer is made from a mixture of polyols, polyglycol and water. Suitable polyols include glycol, propanediol, glycerol, or sorbitol. 

A term for additives which prevent foods from drying out. Humectants keep marshmallows and shredded coconut soft. Glycerine (glycerol) and sorbitol are utilized for this purpose. 

Figure 7.8 Tensile fracture surfaces of (A) glycerol, (B) sorbitol and (C) polyester amide plasticized soy-based agro-polymers. Reprinted with permission from P. Tummala, W. J. Liu, L. T. Drzal, A. K. Mohanty and M. Misra, Ind. Eng. Chem. Res., 2006, 45, 7491-7496. Copyright 2006 American Chemical Society.

Many companies have patented sugar alcohol hydrogenolysis for PPG production from carbohydrates (eg, glycerol and sorbitol). However, the complex reactivity of the polyhydric alcohols has not been definitively elucidated. Consequently, an xmderstanding of selective CeO cleavage remains an important research challenge. 

Concerning the use of CNC extracted from defined species, cassava starch matrix, plasticized with an equimolar addition of glycerol and sorbitol, has been reinforced with CNC extracted from kenaf fibers, CNC did not affect composite s transparency. 

Reduction. Mono- and oligosaccharides can be reduced to polyols (polyhydroxy alcohols) termed alditols (glycitols) (1) (see Sugar alcohols). Common examples of compounds in this class ate D-glucitol (sorbitol) [50-70-4] made by reduction of D-glucose and xyhtol [87-99-0] made from D-xylose. Glycerol [56-87-5] is also an alditol. Reduction of D-fmctose produces a mixture of D-glucitol and D-mannitol [69-65-8],... 

Boron zirconimn chelates from ammonium hydroxide water-soluble amines sodium or potassimn zirconium and organic acid salts such as lactates, citrates, tartrates, glycolates, malates, gluconates, glycerates, and mandelates with polyols such as glycerol, erythritol, arabitol, xylitol, sorbitol, dulcitol, mannitol, inositol, monosaccharides, and disaccharides [463,464,1592,1593]... 

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