Effects of Sodium Alginate and Guar Gum Matrices on the Structure and In Vitro Digestion of Native Corn Starch after Encapsulation Using Spray Drying

The study aims to investigate the influence of hydrocolloid matrices, including sodium alginate (SA) and guar gum (GG), on the digestive properties of native corn starch (NCS). The native starch is encapsulated with SA (1% w/v), SA (0.75% w/v) + GG (0.25% w/v), SA (0.50% w/v) + GG (0.50% w/v), SA (0.25% w/v) + GG (0.75% w/v), and GG (1% w/v) through a laboratory-scale spray drying process. The results reveal novel comparative and cooperative effects of encapsulant materials on starch hydrolysis. SA is found to be a superior encapsulant in terms of enhancing the slowly digestible starch (SDS) and resistant starch (RS) contents and improving the thermal stability of NCS, which is attributed to its rough matrix structure. This effect is attributed to the rough matrix structure of SA, which may offer greater resistance to water and enzyme penetration. The combination of 0.75% w/v SA + 0.25% w/v GG is found to be the most effective in reducing digestibility and enhancing thermal stability (p < 0.05), likely due to synergistic interactions between the two hydrocolloids. These findings provide valuable information on the effects of hydrocolloid matrices on the digestive properties of NCS and lay the foundation for future research.