advamtages far outweigh its disadvantages, however. The ice glaze is 

 inexpensive, easy to apply, readily adaptable to a production line, 

 and provides a satisfactory protective covering for a variety of fish- 

 ery products. When properly applied sind maintained, the ice glaze is 

 effective in preventing loss of moisture from the product as well as 

 preventing ready access of air to the fish, thus retarding the onset 

 of rancidity. 



Among other types of glazes which have been tried on an ex- 

 perimental scale but so far have not replaced ice glazing on a com- 

 mercial scale are pectinate films, gelatin-baise coatings, waxes, 

 edible oils, and combinations of chemicals and Irish moss extractive. 



Films and wraps ,— Films and wraps make ig) another class of 

 protective coverings for frozen fish. There are a large number of 

 films, foils, resin-coated papers, lacquered papers, waxed papers, 

 plastic-coated papers, and various combinations of laminated papers 

 on the market. Each has its own set of characteristics. The choice 

 of the packaging material is governed by such factors as the protection 

 requirement of the frozen product, the cost of the packaging material, 

 the cost of the packaging operation, and its merchandising features. 

 In general, it can be said that a good wrapping material for frozen 

 fish should be strong enough to resist tearing and puncturing from 

 handling during the packaging operation, pliable enough to make a 

 tight wrap, easily sealable, greaseproof, and durable at low temper- 

 atures. It should inpart no odors or flavors and should have a low 

 rate of moisture-vapor and oxygen transmission. 



Among the more commonly used wrapping materials for frozen 

 fish are cellophane, polyethylene, aluminum foil, vinylidene chloride, 

 rubber hydrochloride filii (plio-film), as well as a variety of coated 

 papers such as waxed paper, vinyl- and saran-coated papers, polyethylene- 

 coated paper, and polyetlr^irlene-coated cellophane. To improve the keeping 

 quality of foods antioxidants are often incorporated into the paper 

 wrappers. 



Packages and cartons . — Packages and cartons used in the 

 industry today have been developed in order to fit them into production- 

 line procedures. The rectangular container made of waxed paperboard is 

 the most widely used in the industry. 



Very little has been done in standardizing containers for 

 frozen fishery products. Containers vary as to types of materials, 

 styles, shapes, and sizes, depending upon the product to be packap;ed 

 and the desires of the producer. 



Frozen-food cartons are usually made of a bleached paper- 

 board stock and are coated with various waterproofing materials or else 

 they are laminated with foil or moisture-vapor-resistant film. The 

 coating material may be an improved wax formula, polyethylene, or some 

 other plastic material. The hinged-cover, self -locking carton coupled 



55 



