Effect of melting combined with ice recrystallization on porous starch preparation: Pore-forming properties, granular morphology, functionality, and multi-scale structures.

In this work, critical melting (CM) combined with freeze-thawing treatment (FT, freezing at -20 ℃ and -80 ℃, respectively) was used to prepare porous starch. The results showed that CM combined with the slow freezing rate (-20 ℃) can prepare porous starch with characteristics of grooves and cavities, while combined with the rapid freezing rate (-80 ℃) can prepare with holes and channels, especially after repeating FT cycles. Compared with the native counterpart, the specific surface area, pore volume, and average diameter of CMFT-prepared porous starch were significantly increased to 4.

Effects of enhanced starch-xanthan gum synergism on their physicochemical properties, functionalities, structural characteristics, and digestibility.

The limited and unstable interactions between potato starch (PS) and xanthan gum (XG) by simple mixing (SM) lead it difficult to induce substantial changes in starchy products. Structural unwinding and rearrangement of PS and XG by critical melting and freeze-thawing (CMFT) were used to promote PS/XG synergism, and the physicochemical, functionalities, and structural properties were investigated. Compared to "Native" and SM, CMFT promoted the formation of large clusters with a rough granular surface and wrapped by a matrix composed of released soluble starches and XG (SEM), thus making the composite more compact to thermal processes, such as the significantly decreased WSI and SP, and increased the melting temperatures.