If the freezing of fish as fillets and other consumer-type products is done aboard the trawler, the choice of methods is quite restricted. If cryogens are to be used, the ship must have holding capacity for a weight at least equal to the weight of fish to be frozen while the ship is at sea. An alternative would be to supply the cryogen to the trawler form a supply ship. If the economics of cryogenic freezing are questionable ashore, it becomes even more doubtful at sea. Quality factors would have to be especially compelling.
Freezing Methods of the Future. Our growing affluence and increasing taste for the better things of life suggest that we might take a "cost be damned" attitude in our desire for top quality. But along with increasing incomes and affluence, industry is experiencing increased pressures from cost squeezes and price strikes by consumers. Cost reduction will continue to be an important if not dominant goal in the food business. I think that conventional freezing methods that can be applied at least cost will continue to produce most of the frozen foods. For specialized products and uses, however, I believe that some of the special freezing practices will find considerable room for growth, particularly as technology expands and the costs of cryogens decrease.
In the matter of reducing the cost of cryogenic materials, I was interested in a recent news item regarding the manufacture of a system for making liquid air, apparently right in the plant where it is used. A cost of 11.25 cents a pound was mentioned for a machine producing 300 pounds of liquid air per hour. This is such a logical development that I don't understand why the idea wasn't suggested years ago. Separation of nitrogen from oxygen and transportation and storage of liquid nitrogen must account for a good part of the 2 1/2 to 3 cent cost of liquid nitrogen. There is danger of oxygen buildup in an immersion-type freezer using liquid air, but in a spray-type unit, the liquid air should present no hazard.
