Use of amidated low methoxyl pectin to produce fish restructured products

Recently, amidated low methoxyl (ALM) pectin has been shown to improve functional and textural properties of surimi. The objective of this work was to determine the effect of ALM pectin on fish pastes and functionality of restructured fish products. Whole muscle of sole (Cyclopsetta chittendenii) was used to obtain solubilized pastes with 2.5% salt and 0 (control), 1, 2, 3 or 5% ALM pectin. Changes in firmness, consistency, expressible water contents and colour parameters (L∗, a∗, b∗, chroma and hue) were measured in pastes. Fish gels were obtained by incubating pastes at 40 °C for 30 min, followed by 90 °C for 15 min. Changes on breaking force, deformation and gel strength of restructured products were measured. ALM pectin decreased significantly (P<0.05) firmness and consistency of pastes when added at 1%. Increases in both parameters were observed using higher ALM pectin levels. Adding ALM pectin to the paste increased the yellowness and redness (P<0.05) according with a∗ and b∗ values. ALM pectin improved significantly (P<0.05) breaking force and gel strength, and decreased the content of expressible water when added at 1 or 2%. Higher level of addition decreased significantly all mechanical properties. Results obtained indicated that ALM pectin at 1% could be employed to improve water holding capacity and mechanical properties of restructured fish products.