Effect of the Freeze-Drying Preservation Process on Some Quality Attributes of Pork Meat (Longissimus thoracis)

Meat preservation processes have been widely studied over time, especially those related to low temperatures (freezing and freeze-drying); however, there is very little research that directly relates the effect of these processes on the structure of meat-and the main meat proteins-and how these changes affect some attributes of the final quality. Pork loin meat (Longissimus thoracis) was used, which was frozen-thawed and freeze-dried-rehydrated to subsequently evaluate changes in its chemical composition and physicochemical parameters such as water activity (a(w)), pH, and water-holding capacity. Physical aspects such as color profile, surface myoglobin fraction, shear force, and histological sections were also evaluated, along with thermal analysis by modulated differential scanning calorimetry. The data obtained were analyzed through different statistical techniques. It was found that the freeze-drying process significantly modifies the interactions of water with the rest of the meat components (p < 0.05), promoting differences concerning samples that were only frozen, allowing us to establish the importance of water and its associations with each other and with proteins on their effect on meat preservation processes at low temperatures.