Heat-moisture Treatment Research Articles

Heat-moisture treatment to modify structure and functionality and reduce digestibility of wrinkled and round pea starches

Heat-moisture treatment (HMT) was employed to modify wrinkled pea (74.2 % and 76.5 % amylose) and round pea starches (35.9 % and 34.8 % amylose) at 35.0 % moisture, 110 or 130 °C, and 6 h. HMT increased the gelatinization temperatures and decreased the gelatinization enthalpy changes, reduced the pasting viscosities and gel hardness, and enhanced the enzymatic resistance of the pea starches in comparison with the native counterparts, with greater extents of changes observed for HMT at 130 °C overall. Although HMT decreased the relative crystallinity and elevated the proportion of amorphous conformation, the remaining double-helical crystallites in the modified samples showed improved thermal stability as revealed by differential scanning calorimetry (DSC). More importantly, the HMT-modified pea starches required a higher heating temperature of 120 °C, rather than 95 °C, in Rapid Visco Analyser to provide greater pasting viscosities and develop firmer gels, suggesting that the modified samples had stronger molecular entanglement than the native counterparts. Such molecular entanglement could also reduce enzymatic digestion of HMT-modified starches after boiling in water. With more diverse functional profiles and increased resistant starch (RS) contents (particularly for the HMT-modified wrinkled pea starches having 22.7–29.9 % RS), the HMT-modified pea starches could be promising new ingredients for food applications.

Heat-moisture-treated rice starches with different amylose and moisture contents as stabilizers for nonfat yogurt

Food producers are interested in enhancing native starch properties without chemical modifications. Here, rice starches were physically modified via heat-moisture treatment (HMT) using different amylose (high, medium, low, and waxy) and moisture (15 %, 20 %, 25 %, and 30 %) contents. Hydration properties and pasting viscosities differed for different amylose and moisture contents. The HMT starch with high amylose content and 15 % moisture (High_HMT15) exhibited the highest final viscosity (6.16 Pa.s), and 31.7 % and 35.1 % increased amount of resistant starch compared to native starch in the granule and paste states, respectively. Hence, High_HMT15 was used as a stabilizer for nonfat yogurt. The nonfat yogurt prepared with 1.0 % High_HMT15 as the stabilizer exhibited 37.3 % reduced whey separation, 2.8 times increased viscosity, a high total solids content, and acceptable sensory properties compared to the nonfat yogurt without starch. These HMT starches can replace chemically modified starches derived from other grains in various food applications.

Hydrothermal treatments of starch impact reaction patterns during subsequent chemical derivatization

Differences in derivatization patterns (using a fluorescent reagent, fluorescein isothiocyanate) of wheat, pea, and potato starches between native granular (NAT) starches and their respective annealed (ANN) and heat-moisture treated (HMT) starches were investigated to reveal structural changes associated with starch hydrothermal treatments. Size-exclusion chromatography with fluorescence and refractive index detection assessed the reactivity of amylose (AM), intermediate chains (IM1 and IM2), and amylopectin branch chains (AP1, AP2, and AP3) within the different starches. Shifts in X-ray diffraction patterns of HMT starches and in the gelatinization properties of both ANN and HMT starches confirmed molecular rearrangement. The reaction homogeneity (wheat and pea) and the overall extent of reaction (pea and potato) increased for HMT starches compared to other starches. The lower reactivities of IM2 chains (HMT starch) and AP3 chains (ANN starch) relative to NAT starches, indicated their involvement in molecular rearrangements and improved double helical order. IM2 and AP branch chains in ANN pea starch also were less reacted than NAT starch chains, suggesting their co-crystallization. Molecular rearrangements in ANN and HMT starches led to altered swelling and pasting viscosities. Thus, changes in the relative crystallinity of individual starch branch chains induced by hydrothermal processing impact the final physical properties.

Influence of oxidation, acetylation and hydrothermal treatment on structure and functionality of common buckwheat starch

The set aim of present work was to investigate the effects of acetylation, oxidation and heat moisture treatment on physicochemical, pasting, gel texture, structural, thermal and morphological properties of common buckwheat starch. Swelling power and solubility of starches reduced after modification except acetylation. Color of buckwheat starch improved after oxidation and acetylation. Paste clarity increased while syneresis reduced following modification with the exception of oxidation. Pasting properties of buckwheat starch revealed increased peak viscosity and breakdown viscosity following modification treatments. Gel texture analysis depicted increased hardness and reduced springiness, chewiness and cohesiveness for modified starches of buckwheat. Diffractograms of starches showed variation in intensity of some bands. Heat moisture treatment increased agglomeration and oxidation caused slight depression on surface of some granules. Relative crystallinity reduced following oxidation and hydrothermal treatment of starch. The gelatinization temperatures were increased in hydrothermal treated starch samples while oxidation and acetylation reduced the gelatinization temperature. The findings of this work would favor the new applications of modified starch from common buckwheat.

Physical modification of high amylose starch using electron beam irradiation and heat moisture treatment: The effect on multi-scale structure and in vitro digestibility.

This study explores a new strategy for manipulating the digestibility of high-amylose maize starch (HAMS) through combinative modifications, namely depolymerization via electron beam irradiation (EBI) followed by reorganizing glucan chains via heat moisture treatment (HMT). The results show that semi-crystalline structure, morphological features and thermal properties of HAMS remained similar. However, EBI increased branching degree of the starch at high irradiation dosage (20kGy), resulting in more readily leached amylose during heating. HMT increased the relative crystallinity (3.9-5.4% increase) and V-type fraction (0.6-1.9% increase), without significant changes (p>0.05) in gelatinization onset temperature, peak temperature and enthalpy. Under simulated gastrointestinal conditions, the combination of EBI and HMT either had no effect or negative effect on starch enzymatic resistance, depending on the irradiation dosage. These results suggest that the depolymerization by EBI predominantly affects the changes in enzyme resistance, rather than the growth and perfection of crystallites induced by HMT.

The effect of heat-moisture treatment changed the binding of starch, protein and lipid in rice flour to affect its hierarchical structure and physicochemical properties.

This study investigated the effect of removing proteins, lipids and starch on the structure, physicochemical properties and digestion properties of rice flour (with 30% moisture) treated with heat moisture treatment (HMT). According to the results, HMT caused the adhesion and agglomeration of the rice flour, promoted the binding between starch, protein and lipid molecular chains and led to the formation of complexes (especially starch-lipid complexes), which hindered the removal of non-starch components. Compared to the untreated rice flour, the HMT treated lipid-removal rice flour had small changes in their crystallinity, gelatinization temperature and viscosity property. After removing protein, the crystallinity, peak viscosity, final viscosity, breakdown and starch digestibility were sharply increased. In particular, the peak viscosity increased from 811 cP to 1746 cP and the enthalpy change increased from 5.33J/g to 10.18J/g. These findings are helpful in understanding the contribution of removing endogenous proteins and lipids to the physicochemical changes of HMT treated rice flour during its heating process and thus can be helpful in controlling the quality of rice flour through HMT.

Insights into the effects of multiple frequency ultrasound combined with acid treatments on the physicochemical and thermal properties of brown rice postcooking

This study was proposed to improve the taste of ready-to-eat rice by suitable organic acid addition with brown rice as the raw material and to investigate the effects of multiple frequency ultrasound combined with glucono-δ-lactone (GDL) on the physicochemical properties of brown rice grains under different treatment conditions, which included the moisture content, appearance, texture profile analysis (TPA) and microstructure of brown rice. This study showed that 2.2 g/100 mL GDL can reduce brown rice's pH < 4.6. Sensory evaluation revealed that its sour taste was similar to that of the control group (without acid), while it complied with the product specification for acidified canned food. The soaking brown rice for 30 min showed 23.3 g/100 mL moisture content, but the soaking process combined with multiple frequency (40/80 kHz) ultrasound at 200, 400, and 600 W enhanced the moisture content to 23.7–25.6 g/100 mL. This heat moisture treatment (HMT) improved the brown rice starch's modified thermal properties and texture while the optimal condition of 25.6 g/100 mL moisture content with multiple frequency ultrasound 400 W combined with 2.2 g/100 mL GDL was satisfactory for producing ready-to-eat brown rice with appearance integrity, improved brightness, and chewiness without unpleasant sourness.

Pengaruh Perbandingan Terigu dan Tepung Millet (Panicum miliaceum L.) Termodifikasi Heat Moisture Treatment Terhadap Karakteristik Roti Manis

&#x0D; &#x0D; &#x0D; Sweet bread is a type of flour-processed product that has a sweet taste, soft texture, and a variety of shapes. This study was aimed to determine the effect of ratio of wheat and millet flour modified by heat moisture treatment on characteristic of sweet bread and to find out the right of the ratio to produce sweet bread with the best characteristic. This research used Completely Randomized Design with a treatment of ratio between wheat flour and millet HMT flour that consisted of 6 levels namely 100%:0%, 90%:10%, 80%:20%, 70%:30%, 60%:40%, 50%:50%. The data obtained were analyzed by variance at 95% confidence level, and if the treatment had a significant effect then it was followed by the Duncan's Multiple Range Test (DMRT). The result showed that the ratio between wheat and millet HMT flour had a significant effect on moisture content, protein content, and crude fiber content for the sweet bread, also had significant effect on swelling power, color intensity, scoring test (color and texture), hedonic test (color, texture, taste, and overall acceptance) for the sweet bread. The ratio of 80% wheat and 20% millet HMT flour had the best characteristic of sweet bread with moisture content 23.39%, protein content 9,24%, crude fiber content 4,28%, swelling power 194.59%, color intensity L* 70.63, a* 4.33, b* 25.00, with sensory characteristic of sweet bread browny-yellow color, soft texture, and hedonic for aroma, texture, taste, and overall acceptance is liked.&#x0D; &#x0D; &#x0D; &#x0D; &#x0D; Keywords: Millet HMT flour, wheat, sweet bread&#x0D; &#x0D; &#x0D;

Modified lotus seed starch and red turnip peel extract based pH responsive edible films

Starch obtained from lotus seed was physically modified through heat-moisture treatment to develop the starch-based biopolymer films. Three different types of films: native lotus seed starch (NLS)- carboxymethyl cellulose (CMC), heat moisture treated modified starch (HMLS)-CMC, and modified starch incorporated with red turnip peel extract (HMLS-RTE)-CMC films were developed. The different filmogenic solutions exhibited non-Newtonian behavior with the shear thinning property and showed weak gel-like and viscoelastic behavior. The three different films' tensile strength ranged from 14.97 ± 0.65–21.13 ± 0.41 MPa and elongation at break ranged from 32.87 ± 1.14–44.31 ± 0.82%. The water vapor permeability in NLS was 3.86 × 10−7 gm−1h−1Pa−1 and in HMLS-RTE film, the WVP was decreased to 2.58 × 10−7 gm−1h−1Pa−1. The findings revealed that the pH-sensitive HMLS-RTE film had higher thermal stability, improved mechanical and moisture barrier properties than the NLS films, making them suitable for the intelligent food packaging system.

Effects of acid hydrolysis level prior to heat-moisture treatment on properties of starches with different crystalline polymorphs

Highly crystalline starches find applications as resistant starch because of their improved thermal stability and reduced enzyme susceptibility. Both acid hydrolysis (AH) and heat-moisture treatment (HMT) have been used to alter starch gelatinization properties and digestibility. This study investigated the effects of varying AH levels (0–9%) prior to HMT on the structures and properties of starches with different crystalline polymorphs, including the A-type corn starch, the B-type potato starch, and the C-type pea starch. HMT resulted in significant increases in gelatinization temperatures and significant decreases in gelatinization enthalpy and α-amylase digestion for all three starches. When combined AH with HMT, all three starches generally displayed increases in gelatinization temperatures, gelatinization enthalpy and relative crystallinity with increasing AH level, but the susceptibility to α-amylase varied with starch type and AH level. Acid preferentially hydrolyzed the amorphous regions involving amylose and amylopectin branch points, and increased hydrolysis levels yielded greater amounts of linear chains that were capable of reorganizing into crystallites during HMT. The greater AH level, up to 9%, combined with HMT promoted the formation of more thermally stable crystallites for starches with different crystalline polymorphs.

Structural changes in chestnut resistant starch constructed by starch-lipid interactions during digestion and their effects on gut microbiota: An in vitro study

The nutritional functions of resistant starch (RS) are closely related to its gut fermentation processes. The aim of this study was to explore the relationship between in vitro digestion and fermentation characteristics of heat moisture treatment induced chestnut starch-lipid (oleic acid; linoleic acid; maize oil) complexes from perspective of ordered structural changes during simulated digestion process. The results showed the formation of ordered structures differed significantly among three complexes with similar RS content (∼40%), while their ordered structures decreased significantly after digestion. In contrast to chestnut starch, starch-lipid complexes could successfully encourage the production of healthy gut bacteria, and the difference in total ordered structure was the key factor in the generation of total short-chain fatty acids especially propionate during fermentation. Interestingly, correlation analysis found the presence of V-type complex might facilitate the proliferation of acetate-produced microbiota especially Lactobacillus, Lactococcus, and Bifidobacterium to produce acetate. Our findings could provide basic data on the creation of starch-based functional ingredients for optimal gut health.

The Impact of Food Processing on the Structure and Hypoglycemic Effect of Oat β-glucan.

The impact of food processing including baking, steaming and bread making, on the structure and hypoglycemic effect of oat β-glucan was studied. The structural analysis revealed the β-D-glucopyranosyl units of β-glucan was unchanged in aforementioned processing. The baking processing endowed β-glucan with increased molecular weight (Mw) and viscosity, which enhanced the capacity of β-glucan to delay starch digestion in vitro, such as the rapidly-digestible starch content decreased, the slowly-digestible and resistant starch content increased, and the glycemic index (GI) value decreased. Meanwhile, the inhibitory activity of β-glucan against α-glucosidase and α-amylase was enhanced by baking processing. By contrast, during steaming and bread making processing, β-glucan showed decreased Mw and viscosity, which accelerated starch digestion in vitro and reduced the inhibitory activity of β-glucan against α-glucosidase and α-amylase. Apart from that, baking processing promoted the physiological and antioxidant properties of β-glucan, but the properties decreased during steaming and bread making processing. The results suggest that oat raw materials can be treated with dry heat and high temperature, avoiding moist heat and fermentation treatments to maximize the hypoglycemic effect of β-glucan.

Effect of Heat-Moisture Treatment on the Structure and Digestibility of Sweet Potato Starch.

The objective of this study was to investigate the effect of temperature changes during heat-moisture treatment (HMT) on the appearance, structure and digestibility of sweet potato starch (SPS). The results showed that after HMT, there were depressions, cavities and fragments on the surface of SPS particles. The polarized crosses of SPS were irregular and partially blurred. The relative crystallinity and short-range order of SPS decreased, while rearrangement and reorientation of the starch molecules occurred and the thermal stability increased. The resistant starch content of SPS reached the highest (24.77%) after 4 h treatment at 110 °C and 25% moisture. The obtained results can provide a reference for the modification of SPS.

Preparation and physicochemical characterization of debranched rice starch nanoparticles from mono- and dual-modification by hydrothermal treatments

Starch nanoparticles (SNPs) are attracting attention due to their novel attributes beneficial to certain applications; their fabrication technique and physicochemical attributes have yet to be systematically investigated. In this study, starch nanoparticles were fabricated from the debranched rice starches of three rice lines employing the mono-modification by annealing treatments for one and five days and the dual-modification by the combined annealing and heat-moisture treatments, and their physicochemical properties were characterized. The highest percent recovery of crystalline SNPs was obtained by the dual-modification treatments (32.6–45.6%), followed by the five-day annealing treatment (23.8–28.7%), and then the one-day annealing treatment (11.7–15.8%). The modified starches showed significant increases in oil absorption capacity, water holding capacity, and solubility and decreases in swelling power and volume fraction compared to their native counterparts. The crystal types were changed from A-type to B-type polymorphs by mono-modification treatment and to CA-type polymorphs by the dual-modification treatment with significant increases in relative crystallinity. The dual-modification treatment resulted in the highest increases in 1047/1022 cm-1, 995/1022 cm-1, and 1047/1035 cm-1 band ratios and the highest melting temperatures and enthalpies. The resistant starch contents of the modified starches were markedly increased and strongly related to the percent recovery and the short- and long-range ordered structures. The results suggest that the dual-modified starches comprised the rigid and densely packing of nanoaggregates with superior oil/water absorption performance and water dispersibility, and high enzymatic resistance, which could be the contributing factors for their utilizations as novel ingredients in food-related applications.

The Effect of Dual-Modification by Heat-Moisture Treatment and Octenylsuccinylation on Physicochemical and Pasting Properties of Arrowroot Starch.

Starch is widely applied in various industrial sectors, including the food industry. Starch is used as a thickener, stabilizer, or emulsifier. However, arrowroot starch generally has weaknesses, such as unstable under heating and acidic conditions, which are generally applied to processing in the food industry. Modifications were applied to improve the characteristics of native arrowroot starch. In this study, arrowroot starch was modified by heat-moisture treatment (HMT), octenylsuccinylation (OSA), and dual modification between OSA and HMT in a different sequence--namely, HMT followed by OSA, and OSA followed by HMT. This study aims to determine the effect of different modification methods on the physicochemical and functional properties of native arrowroot starch. The result shows that both single HMT and dual modification caused damage to native starch granules, such as the formation of cracks and roughness. For single OSA treatment, especially, there is no significant change in granule morphology after modification. All modification treatments did not change the crystalline type of starch but reduced the RC of native starch. Both single HMT and dual modifications (HMT-OSA, OSA-HMT) increased pasting temperature and setback, but, conversely, decreased the peak and the breakdown viscosity of native starch, whereas single OSA had the opposite trend compared with the other modifications. HMT played a greater role in increasing the thermal stability and the retrogradation ability of arrowroot starch. Both single modifications (HMT and OSA) increased the hardness and gumminess of native starch, and the opposite was true for the dual modifications. HMT had a greater effect on color characteristics, where the lightness and whiteness index of native arrowroot starch decreased. Single OSA modification increased swelling volume higher than dual modification. Both single HMT and dual modifications increased water absorption capacity and decreased the oil absorption capacity of native arrowroot starch.

Starch ordered structures control starch reassembly behaviors during heat–moisture treatment for modulating its digestibility

This study investigated the effect of starch crystallinity on starch reassembly behaviors during the heat–moisture treatment (HMT) using starches with A-type crystal content of 0.00%–19.03%. The results showed that HMT reduced the native starch crystal content from 19.03% to 15.02% and increased starch thermostability, leading to a decrease in rapidly digestible starch (RDS) content from 86.91% to 76.71%. Moreover, starches containing a crystal content of 2.51%–8.11% exhibited significant reassembly during the HMT, and the resulting modified starches had more crystals and less RDS of 63.43%–69.31%. Interestingly, starches lacked A-type crystals but had some helical structures exhibiting A-type crystalline structures and lower digestibility after HMT. These findings verified that starch could significantly reassemble to form crystalline structures during the HMT. Controlling the crystal content of starch granules, particularly between 2.51% and 8.11%, was a promising approach for promoting starch reassembly during HMT and reducing starch digestibility.

Improvement of Prebiotic Properties and Resistant Starch Content of Corn Flour (Zea mays L.) Momala Gorontalo Using Physical, Chemical and Enzymatic Modification.

Probiotics are a non-digestible food ingredient that promotes the growth of beneficial microorganisms in the intestines. One of the functional food ingredients, Momala corn flour, is a source of prebiotics with a resistant starch content of 4.42%. Thi s study aimed to improve the prebiotic properties and resistant starch content of modified corn flour (MCF) Momala Gorontalo by using physical, chemical, and enzymatic modification processes. The research methods include physical modification (heat moisture treatment, annealing, autoclaving-cooling cycling, microwave), chemical modification (acid hydrolysis), and enzymatic modification (debranching pullulanase). The results showed that the modified by heat moisture treatment (HMT) increased RS levels 1-fold, annealing modification (ANN) 8.9-fold, autoclaving-cooling one cycle modification (AC-1C) 2.9-fold, autoclaving-cooling two cycles modification (AC-2C) 2.0-fold, microwave modification (MW) 1.3-fold, acid hydrolysis (HA) modification 5.0-fold, and debranching pullulanase (DP) modification 3.8-fold compared with corn flour control without modification. The value of the prebiotic activity of MCF hydrolysed acid (HA) is 0.03, and debranching pullulanase (DP) is 0.02 against Enteropathogenic Escherichia coli (EPEC). The prebiotic effect value of MCF HA and DP were 0.76 and 0.60, respectively. The prebiotic index value of MCF HA and DP were 0.60 and 0.48, respectively. This study confirms that MCF HA and DP are good prebiotic candidates because they have resistant starch content, low starch digestibility, and resistance to simulated gastric fluid hydrolysis than unmodified corn flour.

Processing black rice grains to obtain flour: Influence of pretreatments on mass transfer, in vitro digestibility, and technological properties

AbstractBackground and ObjectivesThe objective of this work was to evaluate the processing of black rice grains to obtain flour and to verify the influence of pretreatments on mass transfer, in vitro digestibility, and technological properties. The grains were submitted to heat moisture treatment (HMT) with a final humidity of 30% at 110°C for 2 h, black rice pretreatment with ethanol (BRE) in the proportion 1:1 (wt/wt) for 5 min/25°C, and high hydrostatic pressure (HHP) under conditions of 200 MPa for 10 min/25°C. Then, the grains were dried at 60°C at an air velocity of 1.5 m/s and ground in an electric multigrain grinder. Was analyzed the mass transfer, in vitro digestion, water, oil, and milk retention capacity, total phenolic compounds (TPC), total anthocyanins (TA), antioxidant activities by (2,2′‐azino‐bis‐(3‐ethylbenzothiazoline‐6‐sulfonic) acid, 2,2‐diphenyl‐1‐picrylhydrazyl, ferric‐reducing antioxidant power, and oxygen radical absorbance capacity Surface appearance by scanning electron microscopy, and thermal analysis by differential scanning calorimetry was carried out.FindingsThe grains when submitted to the HHP obtained a reduction of 58.82% in the drying time, while the HMT promoted an increase of 23.5% when compared to the control. The pretreatments influenced the in vitro digestibility, where the HHP had the highest value (86.33), as well as the highest water, oil, and milk retention capacities. BRE positively impacted TPC, TA, and antioxidant activities regardless of the methods used. HMT promoted the formation of cavities, fissures, and holes on the surface, resulting in a rough appearance and presenting greater thermal resistance with an enthalpy of 12.35 J/g.ConclusionsThis research paved the way for potential commercial applications of black rice flour as an ingredient in functional foods.Significance and NoveltyThis study adds to the significance and novelty of research on black rice processing by evaluating the influence of different pretreatments on mass transfer, in vitro digestibility, and technological properties.

Glutenin-gliadin ratio changes combining heat-moisture treatment significantly influences the in vitro digestibility of starch in recombinant wheat flours

This study aimed to investigate the effect of heat-moisture treatment (HMT) on the in vitro digestibility of recombinant wheat flours characterizing by gluten proteins differ in glutenin-gliadin ratio. Compared with the untreated flours in our previous study, HMT improved the digestion resistance of starch in flours with different glutenin-gliadin ratios. For the HMT strong-gluten flour, the proportional increase of glutenin led to an excessively strong and fragile gluten network that unstable under HMT, which weakened the wrapping of gluten network around starch granules and reduced the long- and short-range order of starch, resulting in the conversion of resistant starch (RS) and slowly digestible starch (SDS) to rapidly digestible starch (RDS); however, the quantitative increase of gliadin induced the conversion of SDS to RS due to the enhanced protein-starch interactions as well as the improved long- and short-range order of starch during HMT. For the HMT weak-gluten flour, the changes of glutenin-gliadin ratio aggravated the broken of protein network and starch granules during HMT, thus improving the starch digestibility in varying degrees. In conclusion, the relative crystallinity of starch mainly affected the content of resistant starch, while the content of slowly digestible starch was more influenced by protein-starch interactions.

Changes in physiochemical properties and in vitro digestion of corn starch prepared with heat-moisture treatment

To investigate the effect of heat-moisture treatment (HMT) on the physiochemical properties and in vitro digestibility of corn starch, the pasting behavior, viscoelasticity, thermal properties, long/short range structure, morphology and in vitro digestion of corn starch treated with different HMT conditions (HMT-20, 25, 30, 35 and 40 %) were characterized. Results indicated that after HMT, the pasting and disintegration behaviors of corn starch were affected and correlated with the moisture content. The dynamic viscoelasticity of corn starch was changed, and when glassy conditions were reached, the elastic properties decreased with increasing moisture while the viscous properties increased, especially for the HMT-40 %. The thermal stability of starch was improved by HMT, although the enthalpy of pasting (ΔH) was reduced. Additionally, the HMT processing also promoted the conversion of RDS to SDS and/or RS (SDS and RS increased to 39.80 % and 31.68 % for HMT-40 %, respectively), which might attribute to the rearrangement of free starch molecules. The present work provides a potential approach to make functional starches with healthy properties.