220 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1942 



SANITATION IN THE FOOD AND BEVERAGE INDUSTRIES 



A large number of installations of suitable equipment radiating 

 the selective bands of ultraviolet rays have been in operation in all 

 kinds of food establisliments and bottling plants and have demon- 

 strated their effectiveness and value. Important considerations are 

 presented. 



Meat industry. — Fresh meat composed of nutritive substances and 

 approximately 80 percent water, an ideal environment for bacterial 

 and mold gi'owths, will spoil unless it is kept properly. The com- 

 monly practiced method of preservation is to place such meats under 

 suitable refrigeration or to keep them in properly operated cold- 

 storage plants. But even under the most ideal conditions, physical 

 and chemical changes occur. Evaporation occurs and there is a ma- 

 terial shrinkage, resulting in a reduction in weight which frequently 

 is an appreciable percentage loss. Certain types of bacteria and 

 molds develop even at the low temperatures used. They produce 

 slime and coatings which affect the odor and flavor and cause a change 

 of the natural color. It therefore becomes necessary to trim the meat 

 and to wash and clean the surfaces to remove the growths and avoid 

 an impairment in flavor, color, and odor. The resultant financial 

 losses are self-evident. The presence in walk-in refrigerators, cold- 

 storage rooms, display boxes and cabinets of properly installed equip- 

 ment radiating the selective bactericidal ultraviolet light and 

 containing low concentrations of ozone (not more than 0.1 percent) 

 has provided a means of reducing the losses and making available 

 more satisfactory and more salable meats for human consumption. 

 Irradiation is said to produce a very slight surface coagulation which 

 does not afi'ect the color, taste, or odor, but it does cause a reduction in 

 the evaporation and subsequent shrinkage. Some workers claim that 

 ultraviolet light as commonly used does not coagulate the surface of 

 the meat, but admit that owing to the sterilizing effect, an additional 

 saving results. The humidity can be increased in the cold environ- 

 ment to 85 or 90 percent, whereas in the cold-storage systems in pres- 

 ent-day service without irradiation, it ranges from 60 to 75 percent. 

 The properly engineered installations provide for the destruction of 

 bacteria and molds not only on the surface of the meats but in all 

 parts of the cooler including the air, ceiling, walls, etc. The reduction 

 of bacterial and mold growths reduces to a minimum the necessity of 

 trimming, and especially deep trimming, with its resultant waste, 

 and the production of bad odors, flavors, and objectionable appear- 

 ances. Ultraviolet light properly used for meat, whether in the large 

 walk-in refrigerator, the refrigerated freight car, the small cooler, 

 or the refrigerated display case or cabinet, will produce an all-round 

 better and more sanitary product, and obviously at a reduced cost. 



