Native and Freeze-Dried Bacterial Nanocellulose as Fat Replacers in Low-Fat Meat Emulsions: A Comparative Study of Techno-Functional Performance

Bacterial nanocellulose (BNC) is gaining interest in multiple industrial applications. BNC dehydration would improve its industrialization while affecting its techno-functional properties (water binding or gelling capacity). This work analyses this aspect in a representative food system where these are fundamental properties: low-fat sausages with pre-emulsified sunflower oil. Native (n-BNC) and freeze-dried (d-BNC) bacterial nanocelluloses were studied at different concentrations. During thermal processing, all batters exhibited the typical viscoelastic transition associated with protein gelation. Formulations containing d-BNC developed a higher final elastic moduli and a broader concentration range of structural reinforcement compared to n-BNC systems. In the cooked sausages, BNC incorporation enhanced hardness, cohesiveness, and water-holding capacity, particularly at intermediate concentrations. Micrographs showed that d-BNC led to a finer and more homogeneous microarchitecture, while n-BNC aggregated in hollows of the meat protein network. Additionally, the Pickering effect of dried BNC produced meat emulsions with smaller oil droplets in agreement with the differences in lightness detected. Results suggest that freeze-dried BNC could be a convenient and effective option for the food industry due to its low weight, longer storage period, and easy handling compared to native BNC.