Effect of blended ratio on microstructure and rheological properties of gelatine-hydroxypropyl methylcellulose aqueous two-phase system

To improve the processability and film-forming properties of hydroxypropyl methylcellulose (HPMC),the effects of the blended ratios of GA and HPMC (0∶10,3∶7,4∶6,5∶5,6∶4,and 10∶0) on the microstructure,physical stability,and rheological properties of the GA-HPMC aqueous two-phase system were investigated by using zein-pectin composite particles as stabilizers.The results showed that adding 0.3% zein-pectin composite particles could reduce the phase separation rate and phase separation degree of GA and HPMC,and this stability effect was enhanced with increasing HPMC proportion (4%~7%);Under the same mass fraction of zein-pectin composite particles,these systems with proportion of GA<5% formed a water-in-water structure with GA as the dispersed phase and HPMC as the continuous phase,and with the increase of the GA ratio,the viscosity and gel strength of GAHPMC aqueous two-phase system increased;The gelling temperature (58.90~54.19℃) of the GA-HPMC aqueous two-phase system was significantly lower than that of pure HPMC solution (61.63℃),and its melting temperature (28.80~32.23℃) was positively correlated with the proportion of GA.The effect of the blended ratios on the stability and rheological properties of the GA-HPMC aqueous two-phase system showed an opposite trend,so a suitable blended ratio should be selected according to the actual requirements.