Industrial Research 



257 



mbccd fermentation presents special problems. Cheese 

 making usually involves the activity of still more spe- 

 cies of micro-organisms and presents problems of even 

 greater complexity. The bacteriology, physical chem- 

 istry, and biochemistry of most of the hundreds of 

 kinds of cheese are still not clear, and an enormous 

 amount of research will be necessary before the cheese 

 maker can manufacture consistently a product of the 

 highest quality. 



Nutritional studies on milk and milk products are 

 assuming increasing importance. Vitamin and mineral 

 content, change of alpha lactose to the beta form, 

 production of soft-curd milk, irradiation of milk, 

 activation and feeding of yeast to cows to increase the 

 vitamin D content of their milk, and the effect of the 

 form of lactic acid upon assimilation are all subjects of 

 present interest and research. 



Eggs. — Stored eggs are subject not only to spoilage 

 by micro-organisms but also to deterioration due to 

 their own enzymes. The industry is interested in 

 improvements over the usual chilling or "cold-storage" 

 preservation; these include oiling of the shell, with or 

 without replacement of the air Ln the egg with carbon 

 dioxide, and storage in an atmosphere with a controlled 

 content of carbon dioxide or ozone. The freezing and 

 drying of eggs also present unsolved problems; for 



instance the diying of egg white by the usual methods 

 used for milk injures the whipping quality. 



Fruits. — It is evident that various biologists would be 

 concerned in research on fruit production, and large 

 producers are employing biologists to assure greater 

 yields and improved quality. The transportation and 

 storage of fruits present difficulties that differ in some 

 respects from those encountered with animal products. 

 In most fruits and vegetables the cells remain alive 

 long after harvesting and continue respiration and other 

 functions. Most fruits reach a certain stage of ripe- 

 ness or maturity desired by the consumer and must be 

 marketed at that stage. For these reasons the time of 

 harvesting, the methods of handling, the use of artificial 

 agents or specific chemicals such as ethylene for increas- 

 ing the speed of ripening, are all of great importance 

 and are the subject of considerable research by biol- 

 ogists. Prevention of mold and bacterial growth is 

 also an important problem. The optimum temperature 

 of storage varies with the fruit to be stored and temper- 

 atures that are but slightly too high or too low may ruin 

 the product. Investigations on this subject by plant 

 physiologists and biochemists continue, but these 

 researches now are concerned chiefly with a study of 

 controlled atmospheres about the fruits, with special 

 attention to concentrations and proportions of oxygen 



Figure 80. — Corner of Food Technology Laboratory, General Foods Corporation, Hoboken, New Jersey 



