sources of the desirable odors and flavors 

 of fresh fish and the undesirable odors and 

 flavors of stale fish. An understanding of 

 the chemistry of flavor and odor changes 

 may result in the development of methods 

 that will prevent fish from getting "fishy" 

 or make it possible to incorporate a fresh- 

 from-the-sea flavor to many manufactured 

 fishery products. 



Anew method of programing the tempera- 

 ture of the column of the gas chromatograph 

 has yielded interesting results. Previous 

 experiments using column temperatures of 

 302° F. (150° C.) enabled only three or four 

 chemical compounds to be separated from 

 the volatiles of haddock flesh. By program- 

 ing column temperatures from -76° F. 

 (-60° C.) to room temperature, however, 

 it has been possible to detect 18 clearly 

 definable compounds in the volatiles of 8- 

 day-old iced haddock. More extensive 

 studies are planned using a new cooling 



and heating system designed to permit auto- 

 matic programing of the chromatographic 

 column at any temperature between -85° F. 

 (-65° C.) and 176° F. ( + 80° C.). 



Composition Research 



Information is being gathered on the 

 protein, oil, mineral, and moisture content 

 of many New England species of fish. This 

 is in addition to physical measurements on 

 fillet yield and size of fish. 



Data accumulated on flounder, cod, 

 haddock, ocean perch, mackerel, and other 

 fish are useful in determining effects of 

 various environmental and processing 

 conditions on changes in the chemical and 

 physical components of these fish. Recently, 

 this research was expanded to include 

 amino acid analyses of groundfish and cer- 

 tain shellfish. 



TABLE 1. — Average composition data for fillets of flounder, cod, haddock, 



ocean perch, and mackerel 



Species analyzed 



Protein 



Oil 



Ash 



Moisture 



Flounder: Percent 



Greysole 16.2 



Yellowtail 17.5 



Blackback 18.8 



Dabs 17. 6 



Cod 17.9 



Haddock 18.8 



Ocean perch 17. 9 



Mackerel 17.3 



DEVELOPMENT OF STANDARDS AND 

 SPECIFICATIONS 



Another phase of the laboratory research 

 program is the development of grade stand- 

 ards and specifications to facilitate the 

 production and purchasing of fishery prod- 

 ucts of uniformly high quality. 



Standards Development 



Grade standards are designed to provide 

 an objective means of measuring and im- 

 proving the quality of the many diversified 

 seafoods produced in this country. These 



standards are voluntarily used by industry 

 and are applied by Fishery Products In- 

 spectors of the U.S. Department of the 

 Interior. Since 1956, standards for seven 

 major New England frozen fishery products 

 have been developed at this laboratory. 

 These products are fish sticks, fishblocks, 

 raw breaded portions, haddock fillets, cod 

 fillets, ocean perch fillets, and fried breaded 

 scallops- -the last two being developed in 

 fiscal year 1961. Standards are being de- 

 veloped for fried fish portions and pollock 

 fillets. The standard for frozen fried fish 

 sticks, adopted in 1956, is now being re- 

 vised to reflect current production 



