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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 4.07 m 2 /g, 7.29 cm 3 /g × 10 -3 , and 3.57 nm, respectively. CMFT significantly increased the thermal stability of starch, in which the To, Tp, and Tc significantly increased from 63.32, 69.62, and 72.90 (native) to ∼69, 72, and 76 °C, respectively. CMFT significantly increased water and oil absorption of porous starch from 91.20 % and 72.00 % (native) up to ∼163 % and 94 %, respectively. Moreover, CMFT-prepared porous starch had a more ordered double-helical structure, which showed in the significantly increased relative crystallinity, semi-crystalline lamellae structure, and the proportion of the double helix structure of starch. The synergistic effect of melting combined with ice recrystallization can be used as an effective way to prepare structure-stabilized porous starch., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

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. The enhanced synergism of PS/XG after CMFT effectively decreased the breakdown viscosity from ~3600 (Native) to ~300 mPa·s and increased the final viscosity from ~2800 (Native) to ~4800. CMFT significantly increased the functional properties of PS/XG composite, including water/oil absorptions and resistant starch content. CMFT caused the partial melting and loss of large packaged structures in starch (XRD, FTIR, and NMR), and the melting and the loss of crystalline structure controlled at approximately 20 % and 30 %, respectively, are the most effective for promoting PS/XG interaction., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The effect of an interchain entanglement on the enhancement of starch and hydrocolloid synergism and their changes in structural and functional properties was investigated. Potato starch (PS) and xanthan gum (XG) were taken as research materials, and critical melting at the onset melting temperature of starch combined with freeze-thawing (CMFT) was used to promote interchain entanglement of PS/XG. The work suggested that CMFT effectively stabilized the aqueous mixture system of PS/XG, showing no phase separation in the water phase system, even after 12 h of storage. The PS/XG composite prepared by CMFT had significantly improved stability against acid, salt, and shear stress during the thermal process DSC demonstrated that CMFT raised the T o of composite to ∼67 from 62.79 °C for native PS. RVA suggested that when pasted in distilled water, acid, and salt solution media, the breakdown viscosity of PS/XG composite declined to ∼380, 660, and 240 from 3615, 1541, and 1114 mPa s for native PS, respectively. CMFT significantly affected the apparent dropping properties of the starch paste, displaying a shorter and more cohesive paste drop against gravity. CMFT effectively improved the gelling properties of starch, with significant improvement in apparent surface adhesion properties and texture of gels, as well as freeze-thawing stability. [Display omitted] •Critical melting and freeze-thawing (CMFT) enhanced potato starch/xanthan gum (PS/XG) synergism. •Release of soluble starches by CMFT effectively promotes interchain entanglement with XG. •Partial melting of the ordered crystalline structure is beneficial to promoting PS/XG interaction. •CMFT significantly improved the pasting and gelling properties of starch. •CMFT effectively raised the thermal, acid, salt, and shear stability of starch paste. [ABSTRACT FROM AUTHOR]

[Display omitted] • Partial gelatinization and freeze-thawing significantly modified the properties of waxy maize starch. • The addition of xanthan gum enhanced these effects of physical treatments. • Treatments affected inner structure and chain arrangement of starch. • Treatments improved the pasting properties and produced a short and cohesive paste. • Treatments increased the gelling ability and stability to freeze-thawing cycles. To improve the pasting and gelling behaviors of waxy maize starch, an aqueous dispersion with or without xanthan gum was subjected to partial gelatinization (5 ℃ above the onset melting temperature of starch) and freeze-thawing treatment. After the treatments, starch granules were slightly deformed, with partial loss of birefringence, and tended to aggregate. The relative crystallinity and thermal stability of waxy maize starch crystals decreased by the treatments. These changes indicated that the treatment affected the inner structure and chain arrangement of the granules. The treated waxy maize starches, however, showed a higher overall pasting viscosity with shorter and more cohesive pastes than that of the native starch. The treated starches formed rigid gels with increased stability against freeze-thawing. The addition of small amounts of xanthan gum enhanced the effects of the treatments. [ABSTRACT FROM AUTHOR]

The present study focuses on investigating the effect of typical melting temperatures (To, Tp, and Tc from DSC) on the dynamic changes of physicochemical properties, functionalities, and gel properties of starch-konjac gum mixture (PS/KGM). The typical melting treatments (HTo, HTp, and HTc) significantly enhanced the PS/KGM synergism, as indicated by the increased thermal stability, and the improved pasting and gel properties. The work suggested that the typical melting effectively stabilized the aqueous mixture system of PS/KGM, showing no phase separation in the water phase system, even after storage for 12 h. The PLM and SEM show that melting at HTo, HTp, and HTc causes partial melting with the loss of birefringence of starch granules, and the granules conglomerate into large clusters with rough surfaces, surrounded by smaller matrices. DSC demonstrated that typical melting significantly raised the To of composite to approximately 77 from 59.10 °C for native. RVA suggested that the melting significantly increased the FV of PS/KGM from 3363 to approximately 8000 mPa s, while the BD decreased from 5009 to approximately 400 mPa·s. Especially in which there is no BD recorded when melted by HTp and HT. The PS/KGM melted by HTo and HTp had more acidic, salty, and shear stability during the thermal process with improved gel texture and freeze-thaw stability than HTc. Partial melting of starch and chain rearrangement is critical for enhancing PS/KGM synergism. As RC% and DM% controlling at approximately 30–35% are the most effective for promoting PS/KGM interaction (HTp > HTo > HTc). [Display omitted] • HTo, HTp, and HTc melting dynamically changed potato starch/konjac gum (PS/KGM) synergism. • Melting significantly improved the thermal stability, pasting, and gelling properties of PS/KGM. • Partial melting of starch and chain rearrangement is critical for enhancing PS/KGM synergism. • HTp melting is the most effective in promoting PS/KGM synergism. • Melting degree and relative crystallinity loss in a range of 30–35%% is the most effective. [ABSTRACT FROM AUTHOR]

Porous starch is one of the widely used multifunctional materials in food and pharmaceutical industries. This work was carried out to prepare porous starch by a novel clean-label method of critical melting (CM) and freeze-thawing (FT) treatment. Porous starch prepared by CMFT showed observable grooves and holes on the surface, channels and cavities inside the granule. Repeated FT after CM promoted the formation of porous structures, in which freezing rates showed different effects on the pore-forming properties of starch granules. Compared to the native counterpart, porous starch prepared by CMFT showed significantly increased thermal stability as shown by water solubility, swelling power, DSC, and RVA. CMFT treatment significantly increased water and oil absorption of porous starch from 85 to 75% (native) up to about 160 and 100%, respectively. Moreover, CMFT prepared porous starch showed the appearance of a visible diffraction peak at 20°, indicating a more ordered double-helical structure in starch granules. The synergistic effect of CM combined with FT could be used to prepare porous starch with "clean-label". [Display omitted] • Critical melting with freeze-thawing could be used for porous starch preparation. • The prepared porous starch has an increased thermostability. • Treatment significantly increased the water and oil absorption of porous starch. • Melting energy and ice crystals recrystallization are critical for porous structure formation. • Reassociation of leached soluble starches during treatment raised thermostability of starch. [ABSTRACT FROM AUTHOR]

Critical melting pretreatment for granular swelling and soluble starch release was performed before freeze-thawing (FT) to enhance the effect of FT treatment on structure modification of potato starch. The critical melting temperature applied was based on the onset melting temperature (T o) of the native potato starch. After pretreatment, the effect of multiple FT cycles on the morphology, structure, and functionality was investigated. The pretreatment effectively induced granular swelling and partial disruption of the crystalline structure by increasing the volume of water molecules inside the granules. The pasting pattern changed obviously after treatments with the significantly increased final viscosity (up to 5000 from 2900 mPa s) and decreased breakdown (1/5th of native starch). Soluble starch released due to the both critical melting and FT treatments had a strong tendency to reassociate outside the granules, which effectively raised the thermal stability of starch granules. Moreover, increased water (∼109–∼164%) and oil (∼56–∼64%) absorption of starch at room temperature were observed. The synergistic effect of the combination of critical melting pretreatment and mechanical force of ice crystals effectively modified the properties of potato starch, suggesting a useful clean-label method for starch modification. [Display omitted] • Pretreatment enhanced modification effect of freeze-thawing on potato starch (PS). • Critical melting pretreatment applied is based on onset melting temperature of PS. • The combined treatment changed the morphology, structure, and functionality of PS. • Thermal stability of PS granules raised significantly after the combined treatment. • Partial disruption of chain arrangement and soluble starch release plays a key role. [ABSTRACT FROM AUTHOR]