Deep-freezing

The small condensing surface required by a domestic appliance such as a deep-freeze may allow the use of the outside metal skin of the appliance itself as a surface condenser. In such a construction, the condenser tube is held in close mechanical contact with the skin, so that heat is conducted through to the outside air, where it is lost by natural convection. This system is restricted to a few hundred watts. 

A similar product is available for domestic use. Plastic containers hold a eutectic solution, and these are frozen down by placing these elements in the domestic deep-freeze cabinet. Once frozen, they can be used in picnic baskets, etc., for the short-term storage of cold foods, wines, ice cream, etc. 

The compound is very soluble in most organic solvents. In order to get a high recovery, it is necessary to complete the crystallization in the deep freeze. From aqueous ethanol the aldehyde crystallized in high yield as the hemihydrate, m.p. 95°. 

To produce Fusarium sp. for meat substitutes the aseptic system must be operated with recovery by filtration followed by deep-freezing. The cost is thus 0.649 + 0.04 + 0.001 + 0.04 = 0.730 per kg biomass. 

Watson, P.F. Plummer, J.M. (1985). The responses of boar sperm membranes to cold shock and cooling. In Deep Freezing of Boar Semen (Johnson, L.A. Larsson, K., eds.), pp. 113-128, Swedish University of Agricultural Sciences, Uppsala, Sweden. 

The spray solutions should always be made up fresh [3]. The colorless dipping solution can be stored in the deep freeze for 2 weeks [22]. 

A new possibility for isolation of the exopolysaccharides in deep freezing of the culture medium (-18°C) was arrived at in the course of our research (Sample 2, Polysaccharide fraction I). 

From the results it can be concluded that the decrease in dissolved organic carbon with storage time is always lowest when the samples come deep frozen deep freezing in a glass ampoule resulted in the lowest decline. Even under these conditions the storage time should be as low as possible. 

Deep freeze (—18°C) Samples with high enzymatic activity Perishable goods/products Less stable analytes Samples which liquefy on thawing Aqueous samples... 

All samples should normally be allowed to reach ambient temperature before analysis. Care should be taken to avoid hygroscopic samples taking up water, both when stored in a deep freeze or refrigerator and when warming back to room temperature. 

This recrystallisation releases water. This is probably why, although deep freezing prevents starch retrogradation, refrigeration at temperatures above zero causes bread to stale faster than storage at ambient temperature. 

Cassidy, W. A., Olsen, E., Yanai, K., Antarctica A Deep-Freeze Storehouse for Meteorites, Science, 1977, 198, 727-731. 

Hybrid cultures as well as other permanent lines of cells maintain the deep freezing (-196 C) and are saved this way. One of the problems of hybrid cultures maintenance and cultivation, especially interspecific, is the segregation of chromosomes. Therefore, the control of desirable correlation saving between hybridization partners chromosomes is obligatory. 

Enzymes have different degrees of stability after their collection. Alkaline phosphatase demonstrates up to 10% increased activity after a few hours at room temperature (B15). Most enzymes are not stable at room temperature, but can be preserved in the refrigerator for short periods or in the deep freeze for relatively long times. In Table 4 are tabulated the reported stabilities of many serum enzymes. It must be realized that the problem of enzyme stability is complicated by the fact that the isoenzymes of a particular enzyme may have different stabilities and that specimens with high activities may react differently than those with normal activities (KIO). Although it is indicated in Table 4 that serum... 

Enzyme Room temp., 20°-25°C Refrigerator, 4°-8 C Deep freeze, -20°C... 

Schwartz, M. K., Daniel, O., Ying, S. H., and Bodansky, O., Effect of storage in deep freeze upon activity of urinary acid phosphatase. Amer. J. Clin. Pathol. 26, 513-516 (1956). 

Health hazards from drug residues in food depend on the frequency and degree of human exposure. Increase in the degree of human exposure occurs when injection sites are accidentally consumed. Continuous exposure is more probable when a side or quarter of a contaminated food animal is purchased by a consumer for deep-freeze use. Basic antibiotics such as chloramphenicol, erythromycin, tylosin, and oleandomycin, are more likely to accumulate in tissue at a higher concentration than in plasma due both to ion trapping, which results from a pH difference between blood and tissue, and to the innate lipid solubility of the compounds (1). A factor with the potential to reduce the drug residues intake is that most animal tissues are cooked before eating, which may decrease 269... 

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