CMC-tuned Pickering emulsions: stability and in vitro digestion

This study investigated how the degree of substitution (DS) of carboxymethyl cellulose (CMC) regulates the stability and gastrointestinal fate of Pickering emulsions stabilized by β-cyclodextrin/carboxymethyl cellulose colloidal particles (β-CCC). After 28 days of storage, the highest curcumin retention was observed in the DS = 1.2 systems, reaching 87.20% at 4 °C and 81.74% at 25 °C. Rheological analysis revealed superior freeze-thaw resistance but reduced thermal stability in high-DS emulsions. Under simulated gastrointestinal conditions, higher DS led to the formation of larger droplet aggregates, with D [4,3] increasing from 116 ± 5.36 μm (DS 0.7) to 143 ± 4.28 μm (DS 1.2). This structural evolution was accompanied by enhanced lipolysis, with final free fatty acid release increasing from 24.41% to 41.61%. Consistently, curcumin bioaccessibility increased with DS, ranging from 41.54% to 54.38%. Overall, tailoring the DS provides an effective strategy to regulate emulsion stability and digestion behavior for lipophilic nutrient delivery.