Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/18/2007
Publication Date: 6/20/2007
Citation: Bechtel, P.J., Chantarachoti, J., Oliveira, A.C., Sathivel, S. 2007. Characterization of Protein Fractions from Immature Alaska Walleye Pollock (Theragra chalcogramma) Roe. Journal of Food Science 72(5):S338-S343. Interpretive Summary: There are good markets for mature pollock roe; however immature pollock roe is discarded or made into fish meal. The physical and nutritional properties of immature pollock roe have not been reported; which limits its potential use as a unique food or feed ingredient. The objective of this study was to evaluate the physical and nutritional properties of immature pollock roe. We have determined the proximate, mineral and amino acid compositions, fatty acid profile, lipid classes’ distribution, and physical and functional properties of protein powder produced from immature pollock roe. These results indicated that several protein ingredients, which have unique nutritional and functional properties can be produced from immature pollock roe. This research is part of an ongoing effort to enhance utilization of Alaska fish by-products by developing novel food and feed ingredients.
Technical Abstract: There are good markets for mature pollock roe; however immature pollock roe is underutilized. The physical and nutritional properties of immature pollock roe (IPR) have not been reported; which limits its potential use as a food ingredient. The objective of this study was to evaluate the physical and nutritional properties of immature pollock roe and soluble and insoluble protein powders made from the immature roe. IPR samples were obtained during the spring pollock harvest from a seafood processing plant in Kodiak, AK. Soluble (SP) and insoluble protein (IP) fractions were produced by heating IPR, separating by centrifugation and freeze drying. The protein contents of freeze dried IPR, SP, and IP were 81.7, 63.2, and 83.0%, respectively. The amino acid contents of IPR and IP were similar except for isoleucine and valine. However, the amino acid contents of IPR and IP were different from values for SP. Lipid contents of IPR, SP, and IP were 9.2, 9.3, and 11.1%, respectively. Palmitic acid (C16:0; 21.2%), DHA (C22:6'3; 21.2%), and EPA (C20:5'3; 19.0%) were the three most abundant fatty acids in fresh IPR. Emulsifying stability and fat adsorption capacity values for SP were significantly higher than IPR and IP (p<0.05). SDS electrophoresis of IPR indicated a major protein band with molecular weight of 103 KDa in all samples. Results indicate that IPR can be utilized to make a number of unique food ingredients with good nutritional characteristics and functional properties.