Abstract
Effects of psyllium (Plantago ovata) husk powder (PHP) at various concentrations (0, 1, 2, 3 and 4%, w/w) on gelling properties of surimi from threadfin bream (Nemipterus sp.) were investigated. The addition of 1% PHP resulted in the highest increase (50%) in the breaking force (BF) of surimi gel (S), compared to that of the control gel (CON; without PHP). Lower BF was obtained for gel incorporated with PHP at the higher levels (2-4%) (p < 0.05). On the other hand, deformation (DF) was decreased with the addition of PHP at all levels compared to the CON gel. The whiteness and expressible moisture content of gels were decreased with augmenting levels of PHP (p < 0.05). Protein patterns revealed that PHP at all concentrations did not affect the polymerization of the myosin heavy chain. A loss in the elasticity of the gel was attained with the addition of PHP as indicated by decreased storage modulus (G'). A finer and more compact network was detected in gels containing 1 and 2% PHP than that found in the CON. FTIR spectra suggested that the addition of PHP influenced the secondary structure as well as functional groups of myofibrillar proteins. Based on the sensory evaluation, the surimi containing PHP at 1-3% showed a similar overall likeness score to the CON. Therefore, PHP at the optimum level could improve the gelling properties of the threadfin bream surimi with high acceptability.