Date of Award

1988

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

First Advisor

Auttis M. Mullins

Abstract

The production and processing of freshwater crawfish (Procambarus sp.) is an important seafood industry in Louisiana. Year round availability of a consistently high quality product will help maximize marketability of peeled crawfish meat. This study addressed several quality problems associated with fresh and frozen crawfish meat. Fresh, peeled crawfish meat is frequently packaged with hepatopancreas for added flavor in prepared dishes. Sporadic development of mushiness in crawfish meat packed with hepatopancreas was an unpredictable problem for crawfish processors. Hepatopancreatic enzymes were thought to be causing proteoloysis of ice-stored meat. Study results showed significant effects (p $<$ 0.01) of cooking time on the texture of ice-stored meat. Gelatin degradation by hepatopancreas proved to be a good indicator of enzyme activity and adequacy of blanch treatment. A popular preference for red swamp crawfish (P. clarkii) over white river crawfish (P. acutus acutus) is maintained by many processors and consumers. Both species are harvested simultaneously in mixed proportions. Easily recognizable exterior physical characteristics distinguish the two species. Sensory differences of processed tail meat had not been determined. Results showed insignificant differences (p $>$ 0.05) in texture and flavor between the two species. Significant differences (p $<$ 0.0005) in color were determined. The reddish color of the meat and hepatopancreas could be a source of preference for red swamp crawfish. Freezing fresh seafood can provide year round supplies of high quality products. Freezing and frozen storage have been associated with quality deterioration in seafoods. Toughness, excessive drip loss, and moisture loss can be significant quality defects in frozen seafoods, such as crawfish meat. Four freezing and two packaging methods were studied to determine effects on initial meat quality and during $-23\sp\circ$C storage. Freezing method had little effect on microbiological quality indicators, although frozen storage and packaging with hepatopancreas did. Freezing method did not significantly affect meat texture. Frozen storage significantly (p $<$ 0.001) increased toughness. Cryogenic freezing significantly reduced meat drip loss (p $<$ 0.001) and increased (p $<$ 0.05) moisture content. Packaging with hepatopancreas significantly increased drip loss (p $<$ 0.0001) and moisture (p $<$ 0.05), and reduced toughness (p $<$ 0.0001). Results indicate that cryogenic freezing produces better and longer lasting quality in frozen crawfish meat.

Pages

173

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