Novel one-step method to construct gellan gum-zein core-shell structured starch beads for regulating starch digestion.

A simple and efficient one-step method combining ion crosslinking and antisolvent exchange has been developed to construct gellan gum/corn starch@zein (GG/CS@Z) core-shell structured beads. This novel approach aims to reduce the digestibility and digestion rate of starch. The GG/CS@Z beads were comprehensively characterized using scanning electron microscopy (SEM), confocal laser scanning microscope (CLSM), differential scanning calorimetry (DSC), swelling power experiments and in vitro simulated digestion tests, respectively. SEM and CLSM analyses unequivocally confirmed the successful construction of the core-shell structure in GG/CS@Z beads. The encapsulation of starch within the core-shell structure effectively restricted its swelling and gelatinization by inhibiting water contact. Notably, compared to native corn starch, the GG/CS@Z beads exhibited significantly enhanced contents of slowly digestible starch (SDS) and resistant starch (RS), reaching 34.07 % and 26.86 %, respectively. These findings demonstrate the potential of GG/CS@Z core-shell structured beads as functional food ingredients for individuals with cardiovascular diseases and diabetes.