|Sathivel, S - UNIVERSITY OF ALASKA|
Submitted to: Journal of Food Biochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 7, 2007
Publication Date: September 20, 2008
Citation: Sathivel, S., Bechtel, P.J. 2008. A comparison of physical and rheological properties of Arrowtooth Flounder protein made using three different extraction processes. Journal of Food Biochemistry. 32:557-575. Interpretive Summary: Arrowtooth flounder (Atheresthes stomias) is an underutilized flatfish that is found in very large amounts in the Alaskan waters. Using arrowtooth flounder as human foods is challenging due to proteolytic enzymes that soften the flesh during cooking, making it undesirable for many consumers. One alternative to enhance utilization is to produce protein powder from arrowtooth flounder fillets. The objective of this study was to compare functional and physical properties of fish protein powders made from arrowtooth using three methods: heating and fractionation, enzymatic hydrolysis, and fractionation, and alkali protein extraction. Differences were detected between physical and chemical properties of the protein powders and their soluble and insoluble fractions. Results indicate that a series of soluble and insoluble protein powder ingredients can be made from arrowtooth flounder fillets that have different properties and potential uses in food and feed applications.
Technical Abstract: Soluble(s) and insoluble(s) fish protein powders were made from arrowtooth flounder (AF) fillets using three methods, which were heating and fractionation (HF), enzymatic hydrolysis (EH), and alkali protein extraction (AE). The AF powders were compared and physical, chemical and rheological properties evaluated. The AES (89.6%) and EHS (84.8%) powders had higher protein contents than other protein powders (72.6-77.8%). Both HFS and HFIS were whiter than the other protein powders. HFS and EHS had the highest nitrogen solubility values and EHS had the highest emulsion stability values. SDS electrophoresis indicated AES and AEIS had more high molecular weight protein bands, while EHS, EHIS and HFS were substantially hydrolyzed and had an abundance of low molecular weight peptides. The flow and viscoelastic properties of the emulsions prepared with soluble AF were investigated using a parallel plate rheometer. The power law model was used to determine the flow behavior index (n), and consistency index (K). The emulsion containing AES had the highest K values (85.3 Pa.s) and the lowest values was for EHS (27.3 Pa.s). Soluble arrowtooth powders exhibited pseudoplastic behavior and viscoelastic characteristics.