Dynamic viscoelastic behaviour, gelling properties of myofibrillar proteins and histological changes in shrimp (L. vannamei) muscles during ice storage

Abstract

Changes in protein quality during ice storage affects the muscle structure, the textural quality, functional properties and the eating quality. Dynamic viscoelastic behaviour and gelling properties ofmeat proteinsin relation to histological changes in white leg shrimp muscles were assessed for 14 days in ice storage. Reduction in Ca2+ ATPase activity of fresh myofibrillar protein (MFP), fading of myosin banding pattern and increased gapping in myofibrils were clearly observed with progress of storage. The quality indices of the shrimp muscle were well correlated with histological and functional properties as a function of ice storage. Solubility of fresh MFP was 86.76% which decreased to 77.06% on the 14th day of storage period. Emulsion capacity found to increase during storage period. Gel strength of white leg shrimp meat was low (81 ± 14 g cm) and further, reduced nearly 60% compared to fresh sample at the end of storage. The considerable reductions (from 535.77 kPa to 246.56 kPa) in storage modulus values were evident of diminishing elasticity and gelling ability of the meat due to ice storage.Therefore, this study usherd that the histological deterioration in myofibrils may be used as an indication of diminishing biochemical quality and gelling behaviour of the proteins.