Date of Award

5-2004

Level of Access

Campus-Only Thesis

Degree Name

Master of Science (MS)

Department

Food Science and Human Nutrition

Advisor

Denise Skonberg

Second Committee Member

Alfred A. Bushway

Third Committee Member

Mary Ellen Camire

Abstract

Omega-3 fatty acids play important roles in promoting human health. Atlantic salmon has a high content of omega-3 fatty acids; however, they are highly susceptible to oxidation, particularly when the salmon is minced in the preparation of value added food products. A variety of chemical preservatives are currently being used to extend the shelf-life of value-added products. Finding a natural alternative to these preservatives may increase consumer acceptance of these products. Also, creating a new market for seafood processing by-products such as crustacean shells will increase the utilization of this natural resource. The objectives of this study were to: 1) evaluate the effects of various chitosan dips on lipid oxidation in fiozen Atlantic salmon fillets; 2) evaluate the effects of various chitosan solutions on lipid oxidation in refrigerated Atlantic salmon mince; 3) evaluate the effects of various chitosan solutions on microbial growth in refrigerated Atlantic salmon mince; and 4) evaluate the effects of various chitosan dips on consumer acceptance of refrigerated Atlantic salmon fillets. The results of this research indicate that chitosan can function as an effective antioxidative and antimicrobial compound in Atlantic salmon. Antioxidant activity tended to increase with increases in the chitosan concentration. Also, incorporating ascorbic acid (AA) and AA plus tocopherols greatly decreased oxidation in the fillets and mince. However, solubilizing chitosan in acetic acid caused a negative impact on salmon color. Future research should be performed to determine if utilizing other organic acids would result in less color bleaching. Results of the sensory evaluations show that after 7 days of refrigerated storage, panelists preferred the high molecular weight plus AA and the low molecular weight chitosan treatments over the untreated fillet. These results coincide with results from the microbial study, in which all chitosan treatments significantly reduced aerobic plate counts when compared to the untreated control. Future research should include a longer refrigerated study to determine how long the chitosan treatments can retard microbial counts, and to determine which chitosan treatments best inhibit microbial growth during storage.

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