OPTIMIZATION OF DRYING CONDITIONS OF INFRARED RADIATION-ASSISTED THERMAL PUMP ON RAW FISH (Pseudapocryptes elongatus)

Abstract

Goby fish bought in Ca Mau city was dried by infrared radiation-assisted heat pump technology, based on Box-Wilson's multi-factor optimal experimental design with impact factors (drying temperature (X1), the concentration of sorbitol (X2), wind speed (X3), and the objective function is the hydration ratio (Y, %). The optimal sample was controlled with the dried sample by heat pump technology and sun drying technology, based on the sensory characteristics, impurities, water activity, total nitrogen, total protein, total aerobic microorganisms, E. coli, Coliforms, Samonella, V. cholerae, and S. aureus. The results showed that rehydrate ratio, drying temperature, wind speed, and sorbitol concentration correlated with each other according to the equation Y = 59,9143 + 0,751607*X1 + 1,71339*X2 + 1,24464*X3- 0,62464* X1X2 - 0,668393* X1X3 + 1,09839* X2X3. Drying temperature affects drying time more than other factors. Optimal conditions for drying goby are sorbitol 10.0%, drying temperature 56 oC, wind speed 2.4 m/s, and a drying time of 5.70 hours with the highest rehydration rate of 62.50%, shortest drying time and higher sensory quality and food safety than air drying and sun drying methods.