PACKAGING 



The meteoric rise in recent years of the quick-frozen foods 

 industry has been accompanied by important developments in the field of 

 packaging research. The seaLfood branch has benefited at least as much 

 from the technical advances made as any other segment of the food 

 industry. 



If not provided with some form of protective coating or 

 covering, frozen fishery products will undergo undesirable changes diiring 

 periods of storage. Among these changes are flavor loss, toughening, 

 dehydration, and rancidity. 



In the early days of freezing and frozen storage, suitable 

 wrapping materials were lacking. Probably the first "package" that came 

 into general usage was the ice glaze that is formed by dipping frozen 

 fishery products in cold water. 



Technological Aspects 



The types of coverings, not counting master cartons, that are 

 currently used in the freezing segment of the industry can be classified 

 into these basic categories: glazes, films and wraps, packages, cartons, 

 and overwraps. A study published in 1956 by the United States Fish and 

 Wildlife Service, Factors to be Considered in the Freezing and Cold 

 Storage of Fishery Products (Fishery Leaflet No. U29), contains a detailed 

 discussion of these packaging materials. The following comments on cover- 

 ings abstracted from this source pertain to all frozen fishery products 

 (including shrimp). 



Package Coverings 



Glazes . — Glazes have been defined as any continuous thin film 

 or coating that adheres closely to the product. The glaze is usually 

 applied on the frozen product by either dipping or by spraying it with 

 a solution of the glazing agent and allowing the glaze to solidify. 

 Among the desirable properties of a glaze for frozen fish are (1) non- 

 cracking. (2) strength to withstand the rigors of handling and ship- 

 ping, (3) low water vapor pressure to minimize evaporation of glaze, 

 (h) light weight and low bixlk, and (5) attractive appearance. 



Although many types of glazes for fishery products have been 

 introduced, the ice glaze remains the only one of commercial importance. 

 It is formed vriien frozen fish are given a short dip in cold water or 

 are sprayed with water which freezes into a thin coating of ice. 



The chief disadvsintages of the ice glaze are its susceptibility 

 to cracking, its brittleness, and its high vapor-pressure which necessi- 

 tates reglazing if the product is stored for any length of time. Its 



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