Freezing proteins

Ice Slurry Flow Utilizing Nano-scale Effects Originated from Anti-freeze Protein. ... 

Prestamo, G., Palomares, L., and Sanz, P. 2005. Frozen foods treated by pressure shift freezing Proteins and enzymes. Journal of Food Science 70(1) S22-S27. 

Herring anti-freeze protein (fiAFP) Increased expression [25]... 

Anti-freeze protein type 1 (AFP) Platichthys spp. (flounder) Multiple freeze-thaw cycles, pH 4 or 7 (Graether et al. 2003)... 

Additional projects in this theme area include Raman measurements of ant-freeze protein, optical measurements of protein folding and collapse, surfaced enhanced Raman scattering (SERS) nanoparticle sensors see the chapter Talley et al) for intracellular measurements, and photocatalytic nanolithography for molecular scale patterning. 

Very recently, we have developed and incorporated into the CHARMM molecular mechanics program a version of LN that uses direct-force evaluation, rather than linearization, for the fast-force components [91]. The scheme can be used in combination with SHAKE (e.g., for freezing bond lengths) and with periodic boundary conditions. Results for solvated protein and nucleic-... 

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). 

Pish silage prepared by autolysis of rainbow trout viscera waste was investigated as a substrate for the plastein reaction using pepsin (pH 5.0), papain (pH 6—7), and chymotrypsin (pH 8.0) at 37°C for 24 h (152). Precipitation with ethanol was the preferred recovery method. Concentration of the protein hydrolysate by open-pan evaporation at 60°C gave equivalent yields and color of the final plastein to those of the freeze-dried hydrolysate. 

Ultrafiltration (qv) (uf) is increasingly used to remove water, salts, and other low molecular-weight impurities (21) water may be added to wash out impurities, ie, diafiltration. Ultrafiltration is rarely used to fractionate the proteins because the capacity and yield are too low when significant protein separation is achieved. Various vacuum evaporators are used to remove water to 20—40% dry matter. Spray drying is used if a powdery intermediate product is desired. Tyophilization (freeze-drying) is only used for heat-sensitive and highly priced enzymes. 

Freeze drying, or lyophilization, is normally reserved for temperature-sensitive materials such as vaccines, enzymes, microorganisms, and therapeutic proteins, as it can account for a significant portion of... 

Ice-cream is a product which has been developed since mechanical refrigeration became available. Ice-cream mixes comprise fats (not always dairy), milk protein, sugar and additives such as emulsifiers, stabilizers, colourings, together with extra items such as fruit, nuts, pieces of chocolate, etc., according to the particular type and flavour. The presence of this mixture of constituents means that the freezing... 

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