*2.4. Water Activity (aw) and pH*

The water activity (aw) of sausages was measured by a four-channel desktop water activity meter (Hygro Lab 2, Rotronic, Bassesdorf, Switzerland) at 25 ◦C. The sausage (10 g) was chopped and put into the water activity meter with 75% RH at 25 ◦C for 20 min, and then the data were recorded.

The pH values of sausages were characterized by a portable digital potentiometer (pH meter, Mettler Toledo, Zurich, Switzerland). The sausage (10 g) was crushed in 90 mL distilled water by a homogenate (Changzhou Magnetar Instrument Co., Ltd., Guangzhou, China). Then, we filled the mixture and measured the pH value of the solution at 25 ◦C in triplicate.
