Industrial Research 



349 



Typical of the more vital modern industries which 

 are largely served technically by biochemistry are the 

 entire food industry, phai'maceuticals, the agricultural 

 industry with its many ramifications, those chemical 

 industries which are particularly concerned with sol- 

 vents derived from living organisms and other chemicals 

 most efficiently biologically produced, the leather 

 industry, and industries dealing with the production and 

 preparation of natural gums, resins, waxes, and fats, 

 and their intermediary or byproducts. These industries 

 make up a block of commercial and technological 

 activity which is of very great importance to the 

 Nation as a whole, both in the relatively indispensable 

 quality of the products manufactured and in the relative 

 volume of commercial exchange involved. 



The contributions of biochemistry to the food indus- 

 try have been legion, but it wiU be worth while in 

 passing to mention a few of the more striking and more 

 recent ones, as typical of many more. The entire 

 practice of food refrigeration, of great importance to 

 national health and the foundation of a large industry, 

 has been almost uniquely the product of the efforts of 

 the biochemist, the biophysicist, and the mechanical 

 and refrigeration engineer. To the biochemist has 

 fallen the task of determining the optimum conditions 

 of refrigeration for various edible commodities, and of 

 investigating minutely the physical, but especially the 

 chemical, changes that take place in food preservation. 

 His has been the responsibihty of studying the incidence 

 and growth of molds and fungi under conditions of 

 refrigeration, the changes of cell structure in refriger- 

 ated foods, the stability of vitamin content under 

 these conditions, the action of natural enzymes at low 

 temperatures, and the rates of gas exchange in refriger- 

 ated foods, to say nothing of that most difficult and 

 important subject of investigation, the absorption of 

 objectionable odors by refrigerated foods of delicate 

 flavor. The work of the biochemist in food preserva- 

 tion tas reached a climax of importance in two closely 

 related fields. The first is that of the so-called "quick 

 freezing" of foods — a process now of high importance. 

 The great importance of flavor and texture in quick- 

 frozen foods has necessitated an extremely careful 

 study of the modification of cell structure under freez- 

 ing, with a view to eliminating mechanical distortions of 

 cell walls and destruction of cell products insofar as 

 possible. It has also necessitated a much intensified 

 investigation of the activity of enzymes in frozen food, 

 with a view both of eliminating the harmful effects of 

 autolysis on the one hand and of preserving insofar as 

 possible the valuable properties of vitamins on the 

 other. The second field where biochemical research in 

 food preservation has been of particular value has 

 involved the ripening and the preservation of fruit. 

 Studies of the rate of respiration and other gas exchange 



in bananas have Ix^on important to the successful mass 

 transportation of that fruit which now forms the basis 

 of a major industry. Biochemical studies of the re- 

 action of pigments in the fruit skin to ethylene com- 

 pounds and other related chemicals have made possible 

 the artificial ripening methods now such a boon to the 

 citrus industry. 



Studies of the processes of drying, lyeing, and sul- 

 furing in fruit preservation have been of equal value, 

 and their successful prosecution, very largely by bio- 

 chemical methods, has made possible a considerable 

 proportion of the American raisin, dried apricot, and 

 prune industry. Hand in hand with this work has come 

 the study of the biochemicar action of preservatives, 

 especially in the fruit-juice field, both upon the product 

 and upon the consumer. 



The biochemistry of enzyme changes in meats is 

 quite as important as that of vegetable foods. The 

 enzyme papain, and some of the other naturally occur- 

 ring enzymes of fruits, notably of the pineapple, have 

 been found to have a very marked action on meat prod- 

 ucts, and have now been commonly adapted for the 

 "tenderization" of sausage coverings in that industry, 

 with good success. The mechanism of the action is 

 being studied further. It has been found that the color 

 of beef, a very important quality in determining its 

 marketability, bears a close relation to the biochemistry 

 of the meat, and that, other things being equal, meat 

 of a higher sugar content tends to be of a more brilliant 

 red color. 



The biochemistry of bacteria is an extremely impor- 

 tant fi^eld for the food industiy. On the one hand, 

 knowledge of this kind permits closer and more intelli- 

 gent control of noxious micro-organisms at every stage 

 of food preparation and preservation. On the other — 

 and almost equally important — it opens to industry 

 the important fields of the cultivation of beneficial 

 strains. The applications are multifarious. Bacterial 

 reactions are at the base of very many activities, includ- 

 ing manufacture of cheeses and alcoholic beverages 

 among the consumables, the production of many com- 

 mercial solvents and other chemicals, which at present 

 are or may be synthesized by bacteria more economically 

 than by any other means, and, not the least important, 

 the preparation and preservation of farm stock feeds 

 for the agricultural and agronomical industries. An 

 important field has also developed rather recently about 

 the use of bacteria, and especially of microfungi, 

 directly as food. The high food value of the larger 

 fungi, as exemplified in the mushrooms, has long been 

 recognized. It has only been fairly recently, however, 

 that the great value of some of the yeasts for direct 

 consumption has attracted the attention whicli it 

 deserves. This is a relatively virgin field which the 

 work of the biochemist alone can be expected to expand. 



