Protein extraction pH and cross‐linking affect physicochemical and textural properties of protein gels made from channel catfish by‐products

Autor: Sam K.C. Chang, Yuqing Tan
Rok vydání: 2021
Předmět:
Zdroj: Journal of the Science of Food and Agriculture. 101:4799-4807
ISSN: 1097-0010
0022-5142
Popis: Background Channel catfish farming is very important aquaculture in the Southern states of United State. However, huge amounts of by-products are generated from catfish fillet processing industries. The by-products (mostly heads and bone frames) are excellent sources of proteins. Currently, catfish by-product has little value, and is regarded as a 'waste', which if not utilized properly would cause serious environmental pollution. Therefore, to find a way to utilize those by-products is critical for the economy of aquaculture. Method Protein isolates were extracted from the mixture of catfish by-products (heads and frames) with different alkaline conditions (pH 7.5-11) and made into protein gels. Secondary structures of extracted protein isolates were studied. Microbial transglutaminase (MTGase, 0-4 U/g of proteins) was incorporated to improve gel structure. Gelling, physicochemical, textural and thermal properties of protein gels treated with/without MTGase were investigated. Protein pattern changes of MTGase treated protein gels were studied and the microstructures of protein gels were analyzed. Results Alpha-helicity of protein isolates made at pH 11 was 21.5% lower than that extracted at pH 8.5. Storage modulus (G') of protein gel decreased with the increasing in extraction pH (pH > 9) of the corresponding protein isolate. MTGase treatment exhibited significant effect on denaturation temperature and enthalpy of protein gels. Excessive MTGase (> 2 U/g) could weaken the gel structure. Conclusion Protein isolates can be extracted from catfish by-products and made into protein gels which is a value-added product. This article is protected by copyright. All rights reserved.
Databáze: OpenAIRE
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