Thermal characteristics and state diagram of Penaeus vannamei meat with and without maltodextrin addition

Adsorption isotherm and thermal characteristics of freeze-dried Penaeus vannamei meat containing 5% maltodextrin (PV-MD) and maltodextrin free (PV) were investigated and modeled to develop state diagrams. Freezing point (TF) and glass transition temperature (Tg) were fitted to Chen's equation and Gordon-Taylor equation, respectively. Tg of P. vannamei meat increased with maltodextrin addition and decreased with increasing moisture content due to plasticizing effect. The ultimate maximum-freeze-concentration conditions were observed as characteristics solids content 0.706 and 0.657 g/g sample with characteristics glass transition temperature T′g −74.9 and −67.7 °C for PV and PV-MD, respectively. At 25 °C, the critical water content that ensures the glassy state of the dehydrated samples during storage increased from 0.038 to 0.083 g/g dry solids with maltodextrin addition, while the critical water activity increased from 0.151 to 0.258.