The preservation of the quality of the muscle in frozen Australian red claw crayfish (Cherax quadricarinatus) by pre-storage anti-oxidant dipping treatments

Australian red claw crayfish tails were dipped in either 0.06% (w/w) anti-oxidant solutions (tocopherols, propyl gallate, or rosemary extract) or in water and subsequently stored in a -20°C freezer. At the end of 0, 1, 3, and 6 months of storage, the raw muscle samples were analysed for lipid oxidation, the thermal stability of proteins, cooking yield and shear force. Red claw treated with anti-oxidants showed a lower (P < 0.05) thiobarbituric acid-reactive substances (TBARS) production than the non-anti-oxidant control (dipped in water). Enthalpy of denaturation (ΔH) for the myosin head and shear values for the tails decreased (P < 0.05) in all samples after 6 months of storage, while cooking yield was unaffected by storage. Overall, red claw muscle was quite stable and the oxidation, measured as TBARS values, was small (<0.3 mg kg^-1) but could be further stabilized by anti-oxidant dipping treatments. However the anti-oxidant dipping did not prevent texture softening in red claw muscle during frozen storage.