The Relationship between Rehydration Time and Tenderness at Different Rehydrating Water Temperatures in Freeze-Dried Pork Loin

Abstract

Meat tenderness is one of the key factors determining consumer satisfaction and food quality. Freeze drying is a critical aspect of food preservation. Foods produced this way can be stored for an exceedingly long time, but they are characterized by being very hard in texture and requiring rehydration before use. This study presents an investigation focusing on finding preparation parameters of freeze-dried meat that would enable rehydration when left in an environment below 50 °C for 10 min, qualities that are ideal for hikers or soldiers. The meat samples were cooked at both 100 °C and 120 °C, cooled, and freeze-dried. Optical analysis, conducted using a microscope, was conducted to assess tissue damage. A compact and uniform structure was observed in the samples cooked at 120 °C, whereas fractures and gaps were detected on the surfaces of those cooked at 100 °C. Various rehydration durations and temperatures were explored to attain the samples’ original tenderness, as measured using the Warner–Bratzler method, and identify the optimal rehydration conditions. Based on this investigation, it was determined that with proper preparation, the original tenderness can be restored at temperatures below 50 °C within a 10 min rehydration period. It was determined that the recommended rehydration temperature is 40 °C for a 10 min duration.