Evaluation of textural properties of channel catfish (Ictalurus punctatus Rafinesque) fillet with the natural contour method

A value-added channel catfish (Ictalurus punctatus Rafinesque) product was being developed to explore more profit for this industry. Textural properties played an important role in the quality control and acceptability of both raw and processed products. Due to insufficient study on this topic a reliable method was needed for textural properties evaluations of catfish and other small-scale fish. Textural properties of raw and smoked channel catfish (I. punctatus) fillets were measured by the finger and tooth methods with a Texture Analyzer. A novel sampling technique was used to sample thickness contours on the fillets. Indentation force (g) of the finger method and shear force (g) of the tooth method were measured at different contour levels of four myomere cone bands on the fillets. Shear force and indentation force of the fresh catfish fillets increased with the increasing thickness as measured by the tooth and finger methods. Both methods could be used to measure the textural properties of catfish fillet. The finger method was recommended because of its non-destructive nature and applicability to both raw and smoked catfish samples. The novel sampling technique used in this study was rapid and applicable to irregular fillet shapes including catfish and other fish species. Smoked catfish had decreased indentation force with increased thickness. The dehydration effects and denaturization of fish muscle during the smoking process were main reasons for that. (C) 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.