Congelation

Biology

Fish <Actinopterygii>

Animal science

Perch

Fishery

Ice crystals

Liquid nitrogen

Nitrogen

Thermodynamics

Physics

Organic chemistry

Optics

Microstructure

Crystallography

Chemistry

Bass (fish)

Micropterus

The objective of this work was to investigate the effect of frozen storage temperature on the ice crystal microstructure and physicochemical properties of pre-frozen perch. Perch cube were stored at −18, −40, −80 °C and liquid nitrogen (−196 °C) respectively for one month after pre-frozen in liquid nitrogen for 1 h. With the increase of storage temperature from −80 to −18 °C, temperature-dependent relationship was applicable: cell space, area and amount of ice crystals in frozen samples were gradually increased, Ca2+-ATPase activity and total sulfhydryl content of myofibrillar protein extracted from frozen samples decreased significantly (P < 0.05), shear force and salt-soluble protein content of perch tissues were significantly decreased (P < 0.05), while expressible moisture were increased (P < 0.05). Therefore, −80 °C was recommended as the appropriate storage temperature for pre-frozen perch. Liquid nitrogen was not fit for long-term storage due to the destructive effect on fish quality.

Influence of frozen storage temperature on the microstructures and physicochemical properties of pre-frozen perch (Micropterus salmoides)