Multi-method evaluation of surimi quality from a bycatch species (Trachurus lathami): Physicochemical, textural, sensory, and thermal responses to washing conditions

Abstract

The valorisation of underutilised fish species, such as Trachurus lathami, presents an opportunity to diversify fishery products. This study investigates the physicochemical, textural, sensory, and thermal properties of T. lathami surimi, comparing washed and unwashed samples while considering variables such as mince size, washing solution composition, and washing solution-to-fish ratio. Minced T. lathami exhibited high protein (0.181 g·g-1) and moisture (0.754 g·g-1) content, supporting its suitability as a raw material for surimi production. Main effects analysis revealed that finer mincing (4 mm) enhanced the removal of lipids, pigments, and volatile compounds, reducing fat, a* value (redness), total volatile basic nitrogen (TVBN), and thiobarbituric acid reactive substances (TBARS). A similar effect was observed with increased washing solution ratio, though it also led to lower protein and ash retention. The second alkaline saline washing cycle effectively mitigated moisture overload, improved protein retention, and reduced cooking loss, thereby supporting improved structural and functional properties. Unwashed fish mince was more resistant to puncture, with higher hardness and force at break values, whereas washed samples—particularly those treated with alkaline saline solutions—were softer and more deformable, as confirmed by texture profile analysis. Differential scanning calorimetry (DSC) suggested the removal of sarcoplasmic proteins and increased myosin and actin enthalpy, indicating structural rearrangements. Flash Profile analysis identified key sensory attributes, including cohesiveness, succulence, hardness, and fish flavour, with washed samples showing reduced fish flavour and improved juiciness. This study highlights T. lathami as a valuable raw material for surimi production, with washing playing a crucial role in enhancing its properties and supporting the development of sustainable, value-added seafood products.