Effects of osmotic dehydration packaging on rehydration capacity, moisture distribution, protein quality properties and microstructure of Penaeus vannamei

The aim of this study was to investigate the rehydration characteristics of shrimp treated by osmotic dehydration packaging (ODP). The rehydration rate and moisture distribution of dried shrimp during rehydration were evaluated. Besides, the changes in properties and structure of proteins, digestibility and microstructure of shrimp dehydrated to 60%, 45% and 30% moisture content by ODP were characterized compared with those of the hot air dried (HAD). The results showed that the rehydration rate of dried shrimps treated by ODP to different moisture contents was higher than that of the corresponding HAD. Low-field nuclear magnetic resonance analysis revealed that the relaxation times (T22 and T23) of ODP-treated shrimp increased over time, which indicated an increase in water mobility, contributing to faster and better water uptake. Furthermore, ODP-treated shrimp had less variation in actomyosin solubility, turbidity, total sulfhydryl and carbonyl content. Not only the network structure of myofibers could be preserved, but also the tertiary structure of the actomyosin was more stable. These findings emphasized the effectiveness of low-temperature ODP in mitigating oxidation and aggregation processes, enhancing rehydration and digestibility of the shrimp.