Characterization and value-added utilization of proteins extracted from the by-products from catfish fillet processing plant

Authors: GAO, H. - Mississippi State University; CHANG, S. K.C. - Mississippi State University; Bechtel, Peter; MAHMOND, BARAKAT - Mississippi State University

Submitted to: Annual Meeting of the Institute of Food Technologists
Publication Type: Abstract Only
Publication Acceptance Date: 3/19/2016
Publication Date: 7/17/2016
Citation: Gao, H., Chang, S., Bechtel, P.J., Mahmond, B. 2016. Characterization and value-added utilization of proteins extracted from the by-products from catfish fillet processing plant. Annual Meeting of the Institute of Food Technologists. http://ift.planion.com/Web.User/AbstractDet?ACCOUNT=IFT&ABSID=14195&CONF=IFT&ssoOverride=OFF&CKEY=.

Interpretive Summary:

Technical Abstract: Channel catfish farming is the most important warm water aquaculture in the Southeastern United States. The by-products, including heads, skin, bone frame and viscera, account for 55-65% of the whole fish mass after fillet processing. The by-products contain 35% of protein on a dry basis, and may be extracted for use as functional food ingredient. Currently, the by-products have little value and are regarded as waste, which if not utilized properly would produce environmental pollution. This study’s objective is to extract proteins from catfish waste and to characterize their molecular and fundamental properties for potential utilization as surimi gel products. Proteins in catfish waste (catfish heads and frames) were finely grounded and extracted by pH adjustment (Method 1), salt brine solution (Method 2). SDS-PAGE (sodium-dodecyl-sulfate polyacrylamide gel electrophoresis) was used to determine patterns of the proteins in each step of extraction. The yield of extraction was determined. Fish proteins extracted by the two methods above were utilized for surimi gel making and then subjected to texture analysis, and comparison with commercial surimi products. Results indicated that yield of protein extracted from the catfish frames (pH Adjustment: 20.18% ± 1.78%; Salt Brine Solution: 17.09% ± 2.2%) was significantly (P < 0.05) higher than that from the catfish heads (pH Adjustment: 17.16% ± 2.11%; Salt Brine Solution: 14.25% ± 1.53%). Texture analysis showed gel strength of surimi made from catfish heads was not significantly different with that from catfish frames. Surimi gel made by salt extraction (Catfish Head: 0.45 ± 0.03Kgf/cm2; Catfish Frame: 0.43 ± 0.02Kgf/cm2) had significantly lower (P < 0.05) gel strength than gel made by pH adjustment (Catfish Head: 1.96 ± 0.13Kgf/cm2; Catfish Frame: 1.85 ± 0.11Kgf/cm2). SDS-PAGE results showed the protein composition of the extracted protein was similar to that from the fillet, indicating the integrity of myofibrillar proteins was maintained during the extraction process. Results showed it is possible to extract quality proteins from fish by-products for use as a functional ingredient for surimi making. Successful utilization of catfish waste would increase the profit of the catfish industry and avoid environmental pollution.