Microbial Counts in Salmon Filets

The total mesophilic bacterial counts (MBC), total psychrotrophic bacteria count (PBC), and H₂S-producing bacterial counts (HSPBC) of salmon filets were determined according to Yu et al. (28 (link)). In brief, 25 g meat sample were taken from each group under sterile condition and homogenized with 225 mL of 0.85% sterilized saline water with a stomacher blender for 1 min. From this dilution, a series of dilutions (1:10) were prepared in 0.1% peptone, and 0.1 mL of each dilution was dispensed onto the appropriate medium. Plate count agar (Qingdao Hope Bio-Technology Co., Ltd., Shandong, China) was used for determining total mesophilic bacteria count (MBC) (48 h incubation at 30 °C) and total psychrotrophic bacteria count (PBC) (10 d incubation at 4 °C). The H₂S-producing bacteria count was determined by counting black colonies on Iron agar (Qingdao Hope Bio-Technology Co., Ltd., Shandong, China) after incubation at 25°C for 72 h. Each dilution was performed in three parallels.