Jian Kong

Date of Award

12-2008

Level of Access Assigned by Author

Campus-Only Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Food and Nutrition Sciences

Advisor

Mary Ellen Camire

Second Committee Member

Alfred A. Bushway

Third Committee Member

Denise Skonberg

Abstract

Salmon processing generates edible by-products which currently have little economic value. This trim could be used to create an extruded jerky-style salmon snack by appealing to consumers who wish to increase their consumption of omega-3 fatty acids. Three studies were conducted to utilize salmon trim to create a jerky salmon snack. In the first study, three oil-binding ingredients (tapioca starch, high-amylose cornstarch, and oat fiber) were each studied at the 4% level of incoporation. Oat fiber exhibited superior oil binding capacity among the three formulations, but had the lowest overall consumer acceptability. Extrusion cooking did not adversely affect the content of omega-3 fatty acids DHA and EPA content in Atlantic salmon. In the second study, a shelf-life study was conducted to evaluate the effect of antioxidants on oxidative stability of this intermediate-moisture food product. A control sample with no added antioxidants and four samples with antioxidants (rosemary, mixed tocopherols, tertiary butylhydroquinone and ascorbyl palmitate) were extruded in duplicate in a twin screw extruder. All antioxidants were added at 0.02% of the lipid content. Salmon snacks from each formulation were packaged with flushed nitrogen, and stored at 35°C and 75% relative humidity. Only 48% EPA and 40% DHA were retained in the control samples, and approximately 10% or less of astaxanthin was remained by 24 weeks in all samples. Ascorbyl palmitate showed more pronounced effects on retention of DHA and EPA than the control and other antioxidants in the examined time intervals. In the third study, smoked lateral line trim generated from smoked salmon processing was utilized to create an acceptable jerky snack, which was also high in omega-3 content. Hot smoking did not adversely impact the essential omega-3 fatty acids EPA and DHA in the Atlantic smoked salmon trim. The lateral line dark meat contained higher lipids and concentrations of DHA and EPA than did fillets. A serving of the salmon jerky snack made with smoked trim provided at least one serving of EPA+DHA as recommended by nutritionists. Development of a new value-added product will benefit salmon farmers, wild and farmed salmon processors and consumers in the U.S. by reducing waste, creating new revenue and promoting consumption of high omega-3 fatty acid foods. Extrusion of salmon also provides a model for extrusion of other aquaculture food products.

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