Food crystallization

The primary crystalline polymer based on CHDM is the terephthalate, poly(1,4-cyclohexylenedimethylene terephthalate) (PCT). This polyester was originally developed for fiber applications but has since found wider utility as a reinforced polymer for injection molding and (when copolymerized with a small amount of isophthalic acid) as a material for crystallized food packaging trays. The key property of PCT which sets it apart from other thermoplastic polyesters in these latter applications is its melting point. 

E. Davies, E. Dickinson, and R. Bee Shear Stability of Sodium Caseinate Emulsions Containing Monoglyceride and Triglyceride Crystals. Food Hydrocolloids 14, 145 (2000). 

Davies, E., Dickinson, E., Bee, R.D. 2000. Shear stability of sodium caseinate emulsions containing monoglyceride and triglyceride crystals. Food Hydrocoil. 14, 145-153. 

Saito, Z. 1985. Particle structure in spray-dried whole milk and in instant skim milk powder as related to lactose crystallization. Food Microstruct. 4, 333-340. 

Cardona, S., Schebor, C., Buera, M., Karel, M., and Chirife, J. Thermal stability of invertase in reduced-moisture amorphous matrices in relation to glassy state and trehalose crystallization, /. Food Sci., 62,105,1997. 

Guidance for Industry Regulatory Classification of Pharmaceutical Co-Crystals-, Food and Drug Administration Silver Spring, MD, December 2011. 

Ordinary glucose is ct-glucopyranose monohydrate m.p. 80-85°C and [ajp 4-113-4 . In solution it gives a mixture with the form with [alo 4-52-5 . It is manufactured from starch by hydrolysis with mineral acids, purification and crystallization, and is widely used in the confectionery and other food industries. It is about 70% as sweet as sucrose. 

Sodium Bicarbonate. Many soda ash plants convert a portion of their production to sodium bicarbonate [144-55-8], NaHCO. Soda ash is typically dissolved, carbonated, and cooled to crystallize sodium bicarbonate. The mother Hquor is heated and recycled. The soHd bicarbonate is dried in flash or tray driers, screened, and separated into various particle size ranges. Bicarbonate markets include food, pharmaceuticals, catde feed, and fire extinguishers. U.S. demand was approximately 320,000 t in 1989 world demand was estimated at one million metric tons. 

A good compilation of the functions of fats in various food products is available (26). Some functions are quite subtle, eg, fats lend sheen, color, color development, and crystallinity. One of the principal roles is that of texture modification which includes viscosity, tenderness (shortening), control of ice crystals, elasticity, and flakiness, as in puff pastry. Fats also contribute to moisture retention, flavor in cultured dairy products, and heat transfer in deep fried foods. For the new technology of microwave cooking, fats assist in the distribution of the heating patterns of microwave cooking. 

Ice formation is both beneficial and detrimental. Benefits, which include the strengthening of food stmctures and the removal of free moisture, are often outweighed by deleterious effects that ice crystal formation may have on plant cell walls in fmits and vegetable products preserved by freezing. Ice crystal formation can result in partial dehydration of the tissue surrounding the ice crystal and the freeze concentration of potential reactants. Ice crystals mechanically dismpt cell stmctures and increase the concentration of cell electrolytes which can result in the chemical denaturation of proteins. Other quaHty losses can also occur (12). 

Equipment for food freezing is designed to maximize the rate at which foods are cooled to —18° C to ensure as brief a time as possible in the temperature zone of maximum ice crystal formation (12,13). This rapid cooling favors the formation of small ice crystals which minimize the dismption of ceUs and may reduce the effects of solute concentration damage. Rapid freezing requires equipment that can deHver large temperature differences and/or high heat-transfer rates. 

To prepare a USP-grade Epsom salt, higher purity MgO or Mg(OH)2 is used. USP and food grades require low chloride levels, limiting allowable chloride content of the MgO to 0.08 wt %. Trace impurities including iron and aluminum are precipitated using excess MgO. EoUowing crystallization, the Epsom salt is washed free of mother Hquor. 

A listing of compounds evaluated in the laboratory as cockroach repeUents summarizes 872 synthetic compounds out of 901 bioassayed from 1953 to 1974 (43). EenchoHc acid [512-77-6] (3-isopropyl-1-methylcyclopentanecarboxyHc acid) has been used as a standard repeUent in tests conducted by placing 20 cockroaches in a glass crystallizing dish without food and water and offering them a choice of two cardboard shelters, one of which was treated with 1 or 2 mL of a 1% solution of the candidate in acetone. Counts were made daily for seven days. 

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