Dual modification of arrowroot starch: Interaction effects of heat-moisture treatment and ozone treatment on structure, physicochemical properties, and digestibility

Arrowroot starch has been modified using ozone, heat-moisture treatment (HMT), and their sequential combinations. Both treatments increase solubility, water absorption capacity (WAC), and adhesiveness, while reducing pasting viscosities. Ozone treatment also enhances brightness, hardness, gumminess, chewiness, and freeze–thaw stability (0.03 % syneresis), whereas HMT has the opposite effect. HMT shows much higher adhesiveness (−78.27 gF.s) compared to ozone-treated starch (−17.98 gF.s), and its impact on increasing WAC is also more substantial. Ozone raises slowly digestible starch (SDS) to 24.64 %, while HMT elevates rapidly digestible starch (RDS) to 34.17 % and decreases SDS to 2.20 %. Except for solubility and digestibility, the combined effects are sequence-dependent: ozone followed by HMT amplifies changes, while the reverse order gives additive effects. Some properties, such as WAC, adhesiveness, and RDS, show antagonistic responses. Nevertheless, the dominant structural influence of HMT in reducing SDS often outweighs the positive effects introduced by ozone treatment.