History of Process Freezing, and Application of Blast and Contact Freezers in the Food Industry

摘要

The Food Industry has used various methods to freeze food products over the course of history. The purpose of this paper is to review these methods and the various improvements made in food freezing technology. The paper is not intended to promote one type of technology over another nor is it our intent to provide detailed design information in the selection of that freezer or the technology used. Our main emphasis is how the various technologies used for Blast and Contact Freezers have evolved over history and how they are applied to the food products we use in our every day lives. Food freezing is a major method of food preservation. The preservation of food by freezing relies on the retardation of microbial growth to the point where decomposition due to microbial action does not occur. These low temperatures are also needed to preserve the flavor, odor, color and texture of the food by retarding chemical changes, action of food enzymes and eliminating growth of microorganisms capable of growth near or below 32℉ (0℃). Food freezing retains the fresh quality of the product. Various studies indicate that freezing to 0℉ (-18℃) is most desirable. Freezing time of the product is normally kept to a minimum to preserve texture and quality. There have been many technologies used to freeze food products with improvements made to increase throughput and shorten freezing cycle.