Effects of vacuum tumbling with chitosan nanoparticles on the quality characteristics of cryogenically frozen shrimp

- Chitosan (CH) and chitosan-sodium tripolyphosphate (CH-TPP) reduce microbial growth in shrimp.
- Vacuum tumbling with CH and CH-TPP lowers lipid oxidation in shrimp during frozen storage.
- CH and CH-TPP does not affect the color and texture of shrimp during frozen storage.

A chitosan-sodium tripolyphosphate (CH-TPP) nanoparticle solution was developed and applied to shrimp through vacuum tumbling, and the quality characteristics during frozen storage were evaluated. Four solutions were prepared: (1) a 1% acetic acid (AA) solution, (2) a 0.5% chitosan (CH) solution in the 1% AA solution, (3) a 0.167% sodium tripolyphosphate (TPP) solution in the 1% AA solution, and (4) a CH-TPP solution, prepared by adding 0.167% TPP to the CH solution. Shrimp meat was separately vacuum tumbled with the solutions, cryogenically frozen, and evaluated for quality characteristics during 120 days of frozen storage (−20 °C). Shrimp meat vacuum tumbled with distilled water and shrimp meat without vacuum tumbling were used as controls. CH and CH-TPP treated shrimp had lower aerobic plate counts compared to other treatments during the entire storage time. CH and CH-TPP treated shrimp retained their color, texture, and moisture contents. CH and CH-TPP treatments generated the highest reduction in lipid oxidation compared to other treatments at 120 days of storage at −20 °C. This study showed that a CH or CH-TPP solution combined with vacuum tumbling was effective at reducing aerobic plate counts and lipid oxidation in shrimp during frozen storage while maintaining desired physicochemical properties.