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National Resources Planning Board 



neglected field. Especially neglected have been studies 

 relative to the structure of the seed kernel. In the 

 following discussion of the problems in connection with 

 some of the more important food industries, a few 

 examples of the use of biologists in research will be 

 cited and their more extensive use suggested. 



Aleat and meat products. — Studies of the growth, 

 breeding, and nutrition of meat animals obviously 

 involve research by many kinds of biologists. Then 

 from the time the animal is killed until its meat is con- 

 sumed there is work for biologist and chemist in deter- 

 mining methods for reducing to a minimum undesir- 

 able chemical and physical changes and encouraging 

 desirable changes. Recent studies by bacteriologists 

 on the amount and kind of contamination by micro- 

 organisms at different stages during the handling of 

 meat in the packing plant have shown the importance 

 of further research. The growth of micro-organisms 

 and consequent spoilage of meat is an ever-present 

 problem to be solved. The biologist must investigate 

 not only changes due to micro-organisms, but also 

 those due to enzymes of the meat or to purely chemical 

 reactions. Thus the chilling of meat or freezing by 

 cither quick or slow methods brings problems to the 

 biologist, who must be trained in anatomy, histology, 

 and microscopy as well as in biophysics and biochem- 

 istry. The biologist encounters special problems in 

 changes in taste or odor and in loss of "bloom" and 

 other changes in pigmentation including discolorations. 

 The oxidation of fats, use of antioxidants, and the 

 causes of rancidity still present many problems. In- 

 vestigation is needed on ripening and "tenderizing" 

 meats and on their nutritive value. 



Preservation of meat and meat products by heat 

 presents the biologist with problems. While the proc- 

 essing of canned meats by the usual steam-pressure- 

 cooker methods still deserves study, less adequately 

 explored is the field of processing certain canned meat 

 products such as luncheon meats or hams so that only 

 part of the micro-organisms present will be killed, yet 

 the product will keep for a reasonable time at low 

 storage temperatures. 



Curing, piclding, smoking, and drying of meats are 

 being investigated. The bacteriology of the brine 

 used in curing hams and bacon needs study to enable 

 better control of the curing process. This may lead to 

 the use of pure cultures, an example of which is the 

 addition of cultures of lactobacilli to a certain tangy 

 sausage with consequent improvement in the quality 

 of the product. 



Fish and seafoods. — In general the sea-food industry 

 faces problems similar to those of the meat industry. 

 An important difference, however, is the fact that fish 

 and other sea foods usually are not grown but must 

 be sought where they grow in nature (an exception is. 



of course, the breeding of game fish and planting of 

 lakes and streams primarily for the sake of the sports- 

 man). Nevertheless, the ichthyologist, limnologist, 

 and biochemist are carrying on research of benefit to 

 the commercial fisherman. Two interesting examples 

 of this aid are: A study of the habits of fish to guide 

 the fisherman to the best places to net fish; a study of 

 the organic matter content of the water, or rather its 

 availability; this can be measured by determining the 

 rate of bacterial nndtiplication and the rate of oxj'gen 

 absorption in the water due to bacterial action. The 

 case of decomposition of fish (and other sea foods) 

 both by autolysis and by microbial action, and the fact 

 that fishes usually are harvested at some distance from 

 the place of processing, have given the biologist espe- 

 cially difficult problems. 



Milk and milk products. — While mdk may not be 

 considered an industrial product when first produced, 

 it becomes one as soon as it reaches the market-milk 

 plant, the cheese factory, condensery, or other process- 

 ing plant. The dairy industry is making more use of 

 biologists than are some of the other food industries. 

 Bacteriologists and biochemists in particular are doing 

 research on milk and milk products, especially on as- 

 pects of sanitation, preservation, nutritive properties, 

 and utilization of byproducts. 



Milk is subject to contamination by micro-organisms 

 which may grow and cause spoilage, as well as by path- 

 ogenic bacteria. Because the delicate flavor of milk 

 and certain of its physical characteristics are so readily 

 changed by some of the commonly used methods of 

 food preservation like heat and freezing, its preservation 

 presents problems different from those encountered in 

 most foods. Asepsis, cooling, and pasteurization are 

 commonly employed, but use of pressure, sound waves, 

 ultraviolet rays, etc., is being studied. Sanitary con- 

 trol is not only of interest to the market milk industry 

 but also to the ice cream industry, because of the in- 

 creasing stringency of laws concerrung the bacterial 

 content, more especially that of Escherichia coli, in ice 

 cream. The butter industry is faced with problems 

 concerning the original cream as well as the butter 

 which has been in cold storage for months. The biolo- 

 gist is of assistance in the investigation of the harmful 

 processes which may take place. Evaporated milk 

 presents problems especially to the biochemist interested 

 in the coagulability of the casein as influenced by com- 

 position of the milk. Both the nutrition expert and 

 the bacteriologist find unsolved problems concerning 

 the proper processing of the canned product. 



Fermented milk products are manufactured partly as 

 a means of preservation of milk, but primarily for their 

 inherent characteristics. Fermented milk drinks (but- 

 termilks) are, for the most part, prepared with more 

 than one species of micro-organism, and the resulting 



