Channel Catfish (Ictalurus punctatus) Muscle Protein Isolate Performance Processed under Different Acid and Alkali pH Values
Version of Record online: 6 APR 2011
© 2011 Institute of Food Technologists®
Journal of Food Science
Volume 76, Issue 3, pages E240–E247, April 2011
How to Cite
Davenport, M.P. and Kristinsson, H.G. (2011), Channel Catfish (Ictalurus punctatus) Muscle Protein Isolate Performance Processed under Different Acid and Alkali pH Values. Journal of Food Science, 76: E240–E247. doi: 10.1111/j.1750-3841.2011.02083.x
- Issue online: 6 APR 2011
- Version of Record online: 6 APR 2011
- MS 20100398 Submitted 4/13/2010, Accepted 1/10/2011.
- acid processing;
- alkali processing;
- protein isolate;
Abstract: Channel catfish (Ictalurus punctatus) muscle was subjected to 6 protein extraction and precipitation techniques using acid solubilization (pH 2.0, 2.5, and 3.0) or alkaline solubilization (pH 10.5, 11.0, 11.5) followed by precipitation at pH 5.5. The catfish protein isolate was compared with ground defatted white muscle. Alkali-processed catfish showed increased gel rigidity, gel strength, and gel flexibility compared to acid-processed catfish, which exhibited inconsistent functional performance, increasing and decreasing gel rigidity, gel strength, and gel flexibility. The gel rigidity (G′) at pH 3.0 in the absence of salt had the highest G′ of the acid treatments and was not significantly different from the alkaline-treated catfish muscle (P > 0.05). However in the presence of added salt pH treatment it had the lowest G′ and was different from alkaline treatments (P < 0.05) during break force testing. These results show that pH-shift processing of channel catfish muscle provides highly functional isolates with a potentially broad range of applications. This range of applications is possible due to the modification of the textural properties of catfish muscle protein produced using different acidic or alkaline pH solubility treatments.