51A-30

D. I. Skonberg, Department of Food Science and Human Nutrition, University of Maine, 5736 Holmes Hall, Orono, ME 04469-5736 and B. L. GILLMAN.

Justification: Chitosan, a crustacean processing by-product, is a non-toxic hydrocolloid produced from the de-acetylation of chitin. Chitosan's combination of antimicrobial and gel forming properties make it ideal for the production of edible food coatings. It has been shown to improve weight retention, lower vapor transmission, and prolong storage of fruits and vegetables. Fresh fish fillets, which are highly perishable, may also show improved quality and shelf life when protected with chitosan coatings.

Objectives: The objective of this study was to evaluate the efficacy of a chitosan coating on improving the shelf-life stability of refrigerated fish fillets.

Methods: Forty-eight fresh Atlantic salmon and haddock fillets (100g/fillet) were dipped in 1.75% chitosan (in 2% acetic acid) and allowed to drain. Fillets were individually packaged on styrofoam trays and stored at 5°C for ten days. On days 0, 3, 7 and 10, triplicate sets of coated and control fillets were subjected to total volatile base nitrogen (TVBN), pH, lipid oxidation (TBA) and microbial analyses.

Results: Chitosan coating improved quality of salmon and haddock fillets during the first seven days of storage as indicated by lower TVBN, pH and total plate counts. The coating significantly (p < 0.05) reduced TVBN levels in haddock at days 3 and 7, and reduced TVBN levels in salmon by up to 32% (from 65 to 44 mg N/100g at day 3). pH levels were suppressed in coated versus uncoated haddock and salmon at days 3, 7 and 10. Microbial growth was significantly lower in the coated versus uncoated haddock fillets, while APC results for salmon were less consistent.

Significance: Results suggest that applications of chitosan coating could be an effective method of improving the quality and shelf-life stability of refrigerated fish fillets. Further research is needed to determine appropriate concentrations needed and effects of chitosan coating on sensory quality of fresh fish fillets.