Thermomechanically micronized sugar beet pulp: Dissociation mechanism, physicochemical characteristics, and emulsifying properties

Sugar beet pulp (SBP), the main by-product of the beet sugar industry, has gained increasing attention due to its potential functional properties as a clean-label food ingredient. The aim of the present work was to optimize a food-grade approach for SBP micronization via harsh thermal pretreatment and ultrasonication, after which the micronized SBP was used as an emulsifier. Harsh thermal pretreatment substantially softened the compact particle structure of SBP, thereby improving breakage efficiency by reducing the ultrasonication time to 10 min (suspension stability of ∼100%). During ultrasonication, the particle size of SBP declined from ∼34 to ∼25 μm, which showed long and tangled morphology as fibers (diameter of 50–300 nm). The increased solubility enlarged the specific surface area of SBP from ∼0.6 to ∼3.5 g/m2, endowing it with a porous structure for improved ultrasonic energy adsorption, thereby preventing the degradation of the dissolved pectic polymers. The dissociation of SBP particles contributed to the enhancement of emulsification and was correlated with an increase in suspension stability. These findings provide a feasible strategy for the high added-value utilization of SBP.