Blue Crab Meat 

 I. Preservation by Freezing 



By 



JURGEN H. STRASSER and JEAN S. LENNON 



Central Engineering Laboratories, FMC Corporation, 

 1185 Coleman Avenue, Santa Clara, California 95052 



and 



FREDERICK J. KING 



National Marine Fisheries Service Technological Laboratory 

 Gloucester, Massachusetts 01930 



ABSTRACT 



Freezing was studied as a method of preserving blue crab meat for up to 8 months. 

 The results indicate that a rapid freezing rate, storage below 0° F, and vacuum pack- 

 aging are preferable to minimize losses in the desirable qualities of freshly picked meat. 



INTRODUCTION 



The blue crab {Callinectes sapidus) is one 

 of our most valuable commercial shellfish re- 

 sources both in volume of landings and in value 

 of its food products. This industry is also dis- 

 tinguished by having one of the greatest sea- 

 sonal variations in ex-vessel prices for any 

 shellfish. Several factors are involved, such 

 as the short life span of the animal (2-3 years) 

 and the fact that it must be kept alive until 

 cooked in order to remove the meat. However, 

 a more significant factor is that blue crab meat 

 itself is a highly perishable product. Practi- 

 cally all of the present output is sold as fresh 

 meat which has a shelf life of up to 10 days 

 at 32° to 38° F. 



Because blue crab meat is highly perishable, 

 several methods of food preservation have been 

 considered. Heat sterilization was proposed 

 several years ago (Fellers, 1936) but this treat- 



' Presented at the 30th Annual Meeting of the In- 

 stitute of Food Technologists, May 24-28, 1970. 



ment is unpopular because it causes discolora- 

 tion and development of off'-flavors. Although 

 the chemical nature of these alterations is not 

 completely understood, it is generally accepted 

 that heat-induced breakdown products from 

 the muscle proteins and copper from blood pig- 

 ments are involved (Groninger and Dassow, 

 1964; Elliott and Harvey, 1951). Milder heat 

 treatments have been proposed (Byrd, 1951) 

 and heat pasteurization is used commercially. 

 By using heat to reduce the bacterial popula- 

 tion of freshly picked crab meat, it is possible 

 to extend the meat's storage life for up to 6 

 months at 33° to 38° F (Littleford, 1957). In 

 practice, the heat input to reduce the bacterial 

 population has to be controlled very carefully 

 to avoid the undesirable effects of overcooking 

 on the meat's appearance and taste. Because 

 the tolerance is narrow between the intended 

 and the undesirable effects of this heat treat- 

 ment, the usefulness of this method of preserva- 

 tion is highly dependant on the bacterial pop- 

 ulation of the meat just before it is pasteurized. 



