María Eugenia Golzi

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.

Summary: The effect of cooking time and the solid content was analysed in the techno‐functional properties of lentils and common beans aquafaba, and their powders obtained through spray‐drying. Foam drainage kinetic and emulsion destabilisation were successfully modelled showing that lentil aquafaba had better foaming capacity than beans, due to its higher protein content. Moreover, an increase in cooking time results in more liquid incorporated into the foam and a longer lag phase. Bean aquafaba had acceptable emulsifying capacity, attributable to higher soluble carbohydrates. Additionally, microstructure, Fourier Transform Infrared Spectrometry, rehydration capacity, and flowability of aquafaba powders were studied. Microscopy of dried lentil aquafaba showed damaged and collapsed particles, while bean powder consisted of spherical smooth particles. The dominant factor influencing aquafaba functional properties and powder characteristics was the legume type, attributed to their chemical compositions. These findings broaden the insights of alternative sources of aquafaba and enhance the industrial applicability of these residues through highly rehydratable and functional powders.