Antibacterial absorbent mat based on oxidized bacterial nanocellulose for chilled meat preservation

Bacterial nanocellulose (BNC) as a nanomaterial originating from biomass, has received considerable attention in research concerning food preservation due to its multiple advantageous features; however, its application in chilled meat preservation has been hindered by its inherent lack of antibacterial capability as well as its limited water absorption capacity. In this study, BNC was oxidized selectively into oxidized bacterial nanocellulose (OBC) through 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation, thereby fabricating a preservation mat with antibacterial and high-water absorption properties, which was obtained by subsequent freeze-drying process. The physicochemical properties of the OBC mats with different carboxyl content (OBC-1: 0.25 mmol/g, OBC-2: 0.37 mmol/g, and OBC-3: 0.51 mmol/g) were compared and their effects on the preservation of chilled meat were evaluated. The results indicated that OBCs displayed excellent water absorption capacity and antibacterial properties. Their performance in chilled meat preservation was positively and significantly associated with their carboxyl content. After ten days of OBC application, the pH, total viable count, and total volatile base nitrogen of chilled meat were 6.58, 6.2 (log (CFU)), and 14.7 mg/100 g, respectively, which was superior to commercially available cotton fresh-keeping mats. This study suggests that TEMPO-mediated selective oxidation can effectively resolves the issues of limited antibacterial properties and insufficient water absorption associated with BNC. The prepared OBC mats have great potential in the field of chilled meat preservation.