Date of Award

5-2003

Level of Access Assigned by Author

Open-Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Food Science and Human Nutrition

Advisor

Alfred A. Bushway

Second Committee Member

Rodney J. Bushway

Third Committee Member

Denise Skonberg

Abstract

The lobster fishery is valuable to Maine seafood processors, a commodity worth over $160 million dollars in 2001. Jonah and Rock crab are underutilized Maine seafood species, which are incidentally caught with lobster. Maine seafood processors could process this non-essential catch, and lobster into high quality frozen seafood products to increase national and international markets, which may have a significant economic impact. Cryogenic freezing can retain high quality texture and flavor attributes in seafood. Freezing can still cause cellular damage, however minimal. Sodium tripolyphophate (STP) and sorbitol are noted for their cryoprotectant effects, and tocopherol has been found to have antioxidant effects to help prevent off-flavor and odor formation during storage. This study was designed to utilize a patent developed at the University of Maine to improve seafood quality by injecting food additives to enhance shelf-life of frozen seafood. Two objectives were investigated to determine: 1) effects of sodium tripolyphosphate to maintain quality and increase yield of whole cooked, cryogenically frozen lobster 2) effects of sorbitol and tocopherol to maintain quality of whole cooked, cryogenically frozen Rock crab. STP concentrations of 0.1 and 0.3% prepared in 0.9% saline solution were injected into lobster. Controls were injected with 0.9% saline solution. Crabs were injected in their crusher claw joints with either l g sorbitoV2.5g tocopherol or 29 sorbitoV2.5g tocopherol. Control crabs were not treated. Both crab and lobsters were stored at -15°C until further chemical, physical, and sensory analyses were conducted on reheated samples. Lobsters were analyzed at storage months 0, 2,4, and 6, while crab samples were analyzed at months 0, 3,6, 9, and 12. Lobster results indicate that polyphosphates added at low concentrations may extend shelf-life of cryogenically frozen lobsters, decrease lipid oxidation, maintain texture, color, and flavor attributes, decrease drip loss and increase yield (at 0.3% STP). Crab results indicate that injecting crabs with l g sorbitol/tocopherol may be beneficial in maintaining the shelf-life of whole cooked, cryogenically frozen crab, as indicated by sensory ratings. Significance of this research indicates that Maine processors could economically profit from this injection technology, while meeting future demand for lobster, and creating new markets for Maine crab species.

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