GB545821A - Improvements in the preservation of wrapped food by freezing and the products so produced - Google Patents

Abstract

545,821. Non-fibrous wrapping materials ; preserving food. SYLVANIA INDUSTRIAL CORPORATION. Dec. 13, 1940, No. 17662. Convention date, Dec. 29, 1939. Drawings to Specification. [Class 2 (ii)] [Also in Groups VI and XVII] In a process for preserving food by freezing, the food is encased in a flexible wrapper formed of a non-fibrous hydrophilic colloid containing a softener comprising glycerol and diethylene glycol. The softener maintains the wrapper flexible at sub-atmospheric temperatures, and it does not crystallize at the low temperatures employed in the frozen food industry. The proportion of glycerol to diethylene glycol may be varied over a wide range. The softener may be applied to the wrapper as a solution in water or other diluent. The wrapping material may be in the form of a film-sheet, tube, bag, seamless casing, or carton-lining. It may be treated with the softener by dipping or spraying. The hydrophilic colloid may be gelatin, casein, cellulose hydrate, an alkali-soluble cellulose ether, a hydrophilic cellulose ester, or a waterswelling resin, e.g. a polyacrylic acid or ester resin, low-viscosity urea-formaldehyde resin, or alkyd resin. The film-like material may be provided with a moisture- or water-proof coating on one or both sides. The freezing may be effected by brine freezing processes or air blasting methods. Foodstuffs which may be treated include fruits, berries, vegetables, meat, fowls, and fish.