Adsorption and in vitro controlled–release properties of a soybean cellulose nanocrystal/polyacrylamide–based hydrogel as a carrier for different polyphenols

Polyphenols possessing low bioavailability require material carriers for controlling their release during digestion. This study used a soybean cellulose nanocrystal/polyacrylamide (CP) hydrogel as a carrier to explore the adsorption mechanism and release the properties of different polyphenols (gallic acid (GA), epigallocatechin gallate (EGCG) and tannic acid (TA)) during simulated digestion. Structural characterization revealed that the CP hydrogel interacted with polyphenols via strong non-covalent binding. The adsorption efficiency was considerably affected by the molecular structure and the number of hydroxyl groups of polyphenols (TA > EGCG > GA). The TA-loaded CP hydrogel demonstrated the finest mechanical properties, exhibiting the lowest anti-oxidant activity and anti-bacterial ability. The simulated digestion experiment revealed that the CP hydrogel effectively protected the polyphenols from degradation and controlled their release in the intestine, improving their bioavailability (TA < EGCG < GA). These results provide new insights for enhancing the stability and bioavailability of polyphenols in functional foods.