Effect of the temperature, the wind speed, and the sorbitol concentration on the rehydration ability of shrimp Metapenaeus ensis drying by using infrared radiation-assisted heating pump

Abstract

The paper focused on optimising the drying conditions of shrimps Metapenaeus ensis according to BoxWilson’s multi-factor first-order model based on the objective function of rehydration rate. Shrimp bought in Ca Mau city and dried by infrared radiation-assisted heat pump technology. Sensory, physical (rehydration capacity, impurities, and water activity), chemical (total nitrogen and total protein), and microbiological (total aerobic microorganisms, E. coli) parameters, Coliforms, Salmonella, V. cholerae, and S. aureus) were evaluated on dried shrimp by 3 methods (infrared radiation-assisted heat pump, heat pump, and solar energy). Experiments showed that the equation Y = 57.08 + 1.92*X₁ + 1.15*X₂ -1.05*X₃ + 0.35*X₁X₂ + 0.95*X₁X₃ - 0.625*X₂X₃ exhibited the correlation relationship between rehydration rate
(Y, %) and influencing factors (drying temperature (X₁), wind speed (X₂), and sorbitol concentration (X₃), in which drying temperature (X₁) affects the drying time stronger than other factors. Optimal drying conditions were sorbitol 6.3%, drying temperature (57.5^oC), wind speed (2.1 m/s), and drying time (5.38 hours). Shrimp dried under optimal conditions has the highest rehydration rate of 57.88%, the shortest drying time, and higher sensory quality and food safety and hygiene than air drying and drying under the sun.