HYBRID CATFISH GEL FORMATION AND ITS TEXTURAL PROPERTIES

Abstract

ABSTRACT

Response surface methodology (RSM) was employed to study the effect of pre-incubation temperature (25 to 65 °C) and time (60 to 240 minutes) on the biochemical and textural properties of gels prepared from hybrid catfish (Clarias gariepinus X Clarias macrocephalus). Pre-incubation temperature affected gel solubility, trichloroacetic soluble peptides (TCA-soluble peptides) and textural properties in quadratic, linear and quadratic manner (p<0.05), respectively. There was a significant effect (p<0.05) of pre-incubation temperature on changes in biochemical and textural properties of gels. Each predictive model showed a significant lack of fit (p<0.05), indicating that the models were not adequate for prediction.

The estimation response surfaces for gel solubility showed that an increase in pre-incubation temperature decreased gels solubility. The lowest solubility of pre-incubated sample and cooked gel were found at pre-incubation temperature ranging from 35 to 50 °c for 100 to 220 minutes. At pre­incubation temperature above 50 °c, an increasing in solubility of pre-incubation sample and cooked gel was observed. An increasing of pre-incubation temperature influenced on an increase in TCA- soluble peptides value of pre-incubated sample and cooked gel. Breaking force and deformation of cooked gels increased as pre-incubation temperature increased. At setting temperature above 50 °c, a decrease in breaking force and deformation of cooked gels were observed. The optimum condition for pre-incubation of hybrid catfish minced gel was found to be 45 °c for 150 minutes before pre-incubated sample was cooked at 90 °c for 30 minutes.

Keywords: modori; fish protein gelation; textural properties; hybrid catfish