Effect of ice maturation, freezing and heat treatment on the peelability and quality of cold water shrimps (Pandalus borealis)

Abstract

Steamed (90 s) cold water shrimps (Pandalus borealis) were analysed for the effect of ice maturation (1–4 days) before steaming, frozen storage (2 months at −20 °C) and catching locations (2 batches) with respect to changes in texture, colour and peelability. In addition, the interdependency of the attributes of uncooked and steamed shrimps were assessed by analysing 1760 shrimps in total. Results showed that the longer maturation time the springier and more yellow the ready-to-eat shrimps got. Besides, frozen storage prior to ice maturation and steaming led to springier, chewier and harder shrimps compared to the unfrozen product. Frozen storage also induced increased yellowness, which negatively affected the quality of the shrimps. The expected positive effect of maturation time on peelability could not be confirmed by the mechanical peeling work measurements. Studying the interdependency of steamed and uncooked shrimps showed that the steaming process increased the springiness and decreased the hardness, resilience and chewiness of the shrimps as maturation took place. Furthermore, the steaming resulted in more white shrimps, which were slightly easier to peel. In conclusion, maturation time, freezing and steaming all affected the quality of the ready-to-eat shrimps, whereas the peeling work was not affected.