Thermal Processing Effects on the Textural Attributes of Previously Frozen Shrimp

Shrimp texture changes during thermal processing based on its temperature history. Texture measurements and sensory tests were performed on large, medium, and small tiger shrimp. In isothermal experiments, shrimp were cooked in water at 55, 65, 75, 85 and 95°C for two time periods: for their slowest heating point to reach within 0.5°C of water temperature, and 50% longer than this. Transient experiments were also conducted at 75, 85, 95°C, and in boiling water for a time necessary to achieve a certain microbial lethality. Cooling after heat treatment was done in ice slush and in Ziploc bags in ice slush. Texture Profile Analysis and shear test were performed with a Instron Universal testing machine. Tenderness, juiciness, rubberiness, and overall acceptability were determined by sensory panels and correlated with instrumental results. Temperature significantly affected all textural properties and sensory attributes. High correlation between textural properties and sensory attributes was obtained. This correlation may help in predicting sensory attributes from instrumentally measured texture parameters.