Effect of heat-moisture treatment on the in vitro digestibility and physicochemical properties of starch-hydrocolloid complexes

Insight into the multi-scale structure and retrogradation of corn starch by partial gelatinization synergizing with epicatechin/epigallocatechin gallate

Starch retrogradation is of great importance to the quality of starch-based food. This study investigated the effect of partial gelatinization (PG) synergizing with polyphenol (epicatechin, EC; epigallocatechin gallate, EGCG) on the multi-scale structure and short/long-term retrogradation of corn starch (CS). The PG synergizing with EC/EGCG substantially suppressed the short/long-term retrogradation properties of CS. These could be confirmed by the decreased storage modulus and viscosity, the relative crystallinity (1.54%, 3.56%), and the retrogradation degree (9.99%, 20.18%) of CS during storage for 1, 14 days after PG synergizing with EGCG and EC, respectively. This is because PG treatment promoted the hydrogen bond interaction between disordered starch molecules and EC/EGCG. These were proven by the larger aggregation, more and brighter fluorescents, and the reduced long/short-range order structures in CS after PG synergizing with EC/EGCG. This study is helpful for the development of foods with enhanced nutrition and low-retrogradation.

Effects of Cactus Polysaccharide on Pasting, Rheology, Structural Properties, In Vitro Digestibility, and Freeze-Thaw Stability of Rice Starch

This study combined rice starch (RS) with cactus polysaccharide (CP) at different composites (0.6%, 1.2%, 1.8%, 2.4%, and 3.0%, w/w), and analyzed the variations in the complex gelatinization properties, rheological properties, thermal properties, structural properties, digestibility, and freeze-thaw stability. As a result, the pasting parameters (p < 0.05) and storage modulus (G') together with the loss modulus (G″) decreased as the CP concentration increased; meanwhile, the RS and the CP-RS gels were pseudoplastic fluids. As revealed by differential scanning calorimetry (DSC), incorporating CP into the starch elevated the starch gelatinization temperature while decreasing gelatinization enthalpy, revealing that CP effectively retarded long-term retrogradation in RS. The gel microstructure and crystallization type altered after adding CP. Typically, CP inclusion could enhance the proportion of resistant starch and slowly digestible starch (SDS), thereby slowing RS hydrolysis. Concurrently, adding CP promoted the RS freeze-thaw stability. These findings could potentially aid in the innovation of CP-based food products.

Improvement in Storage Stability and Physicochemical Properties of Whole-Grain Highland Barley Pulp Prepared by a Novel Industry-Scale Microfluidizer System in Comparison with Colloid Milling

The aim of this study was to assess the advantages of an industry-scale microfluidizer system (ISMS) to prepare whole-grain highland barley pulp (WHBP) compared with colloid milling. Storage stability was evaluated by particle size, gravity separation stability, and rheological properties, as well as the microstructure observation by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLMS). The results showed that colloid milling failed to effectively homogenize the material, while ISMS sample surfaces were compact and smooth at higher pressures according to visual observation and SEM. The Turbiscan stability index of WHBP by ISMS was much lower as a result of colloid milling, demonstrating ISMS can improve WHBP stability. WHBP by colloid milling displayed a three-peak particle size distribution pattern, while a single-peak pattern was evident after ISMS treatment. A higher shear rate decreased the apparent viscosity, suggesting that WHBP was a shear-thinning fluid. According to CLMS, ISMS can successfully improve homogenization by disrupting the structures of oil bodies, proteins, and starches. The WHBP prepared by ISMS exhibited a higher β-glucan level than that prepared by colloid milling, and showed a significant increase in β-glucan level with ISMS pressure. These findings indicate that using ISMS to produce WHBP is viable for enhancing its storage stability and nutritional value.

Effect of hydrocolloids on starch digestion: A review

Rapidly digestible starch can increase postprandial blood sugar rapidly, which can be overcome by hydrocolloids. The paper aims to review the effect of hydrocolloids on starch digestion. Hydrocolloids used to reduce starch digestibility are mostly polysaccharides like xanthan gum, pectin, β-glucan, and konjac glucomannan. Their effectiveness is related to their source and structure, mixing mode of hydrocolloid/starch, physical treatment, and starch processing. The mechanisms of hydrocolloid action include increased system viscosity, inhibition of enzymatic activity, and reduced starch accessibility to enzymes. Reduced starch accessibility to enzymes involves physical barrier and structural orderliness. In the future, physical treatments and intensity used for stabilizing hydrocolloid/starch complex, risks associated with different doses of hydrocolloids, and the development of related clinical trials should be focused on. Besides, investigating the effect of hydrocolloids on starch should be conducted in the context of practical commercial applications rather than limited to the laboratory level.

Advancements in enhancing resistant starch type 3 (RS3) content in starchy food and its impact on gut microbiota: A review

Resistant starch type 3 (RS3), often found in cooked starchy food, has various health benefits due to its indigestible properties and physiological functions such as promoting the abundance of gut beneficial microbial flora and inhibiting the growth of intestinal pathogenic bacteria. However, it is challenging to develop starchy food with high RS3 content. This review aims to provide a detailed overview of current advancements to enhance RS3 content in starchy food and its effects of RS3 on gut microbiota. These approaches include breeding high-amylose cereals through gene editing techniques, processing, enzyme treatments, storage, formation of RS3 nanoparticles, and the incorporation of bioactive compounds. The mechanisms, specific conditions, advantages, and disadvantages associated with each approach and the potential effects of RS3 prepared by different methods on gut microbiota are summarized. In conclusion, this review contains important information that aims to provide guidelines for developing an efficient RS3 preparation process and promote the consumption of RS3-enriched starchy foods to improve overall health outcomes.

Insight into the improvement in pasting and gel properties of waxy corn starch by critical melting treatments

To improve the pasting and gel properties of waxy corn starch (WCS), the native starch was modified by critical melting (CM) at the onset temperature (TO), peak temperature (TP), and conclusion temperature (TC) (labeled CMO, CMP, and CMC respectively). CM treatments significantly enhanced the thermal stability of the WCS, as indicated by the increase in the peak gelatinization temperature, pasting temperature, and peak time. In addition, after CMP treatment, the storage modulus, hardness, gumminess, springiness, and chewiness of starch gels significantly increased by 43.29 %, 31.14 %, 23.36 %, 8.26 %, and 61.43 %, respectively, and the syneresis rate significantly decreased by 19.69 % (p < 0.05). These results indicated that CMP treatments significantly improved the gelling ability and freeze-thaw stability of the WCS. These results are ascribed to the partial disruption and enhanced rearrangement of the starch crystalline structure. CMP treatment induced the crystalline structure of starch to be partially disrupted and a hard structure was formed on the surface of starch granules. The hard structure in CMP-treated starch supplied more attachment points for crystalline structure rearrangement during gelatinization. Therefore, the above results indicated that CMP treatments can be used to modify starch to improve the pasting and gel properties of starch-based food products.

Lotus starch/bamboo shoot polysaccharide composite system treated via ultrasound: Pasting, gelling properties and multiscale structure

This study investigated the effects of ultrasound treatment on the physicochemical properties, digestion properties, and multiscale structure of a lotus root starch (LS) and bamboo shoot polysaccharide (BSP) composite system. It also preliminarily revealed the mechanism underlying the modification effect of ultrasound treatment. After 180-360 W ultrasound treatment, the viscosity, thixotropy, and gel viscoelasticity of the LS/BSP paste increased. However, treatment with the ultrasound power of 540 and 720 W decreased viscoelasticity. After 14 days of retrogradation, the hardness and cohesiveness of the LS/BSP gel increased under 180 and 360 W ultrasound treatment but decreased under 540 and 720 W ultrasound treatment. After 540 W ultrasound treatment, RDS content decreased by 17.2 % and resistant starch content increased by 32.5 %. After 180 min of in vitro digestion, the hydrolysis rate of LS/BSP decreased from 97.82 % to 93.13 % as the ultrasound power increased to 540 W. Ultrasound promoted the uniform dispersion of BSP in the starch paste and the movement, orientation, rearrangement, and aggregation of starch and BSP molecular chains. These effects further enhanced the interaction between BSP and starch, resulting in the formation of a dense paste structure with strong resistance to digestive enzymes. This work revealed the mechanism of the effects of ultrasound treatment on LS/BSP and found that 360-540 W ultrasound treatment could improve the physicochemical properties and digestion properties of LS/BSP.

Effect of natural gums on pasting, rheological, structural and hydrolysis properties of kudzu starch

Hydrocolloids have been widely used to adjust properties of natural starches, but related research on kudzu starch is still rare. In this study, we investigated the effects of gum arabic (AG), sodium alginate (SA), locust bean gum (LG), and guar gum (GG) on kudzu starch from the perspective of its particle size, pasting, texture, rheology, dehydration rate, thermal properties, microstructure, and sensitivity to amyloglucosidase. Results showed that GG significantly increased the particle size of starch. Addition of AG led to lower peak-, final- and holding-viscosity. SA increased the retention viscosity of kudzu starch, while LG and GG increased its peak viscosity. Addition of hydrocolloids increased the hardness, chewiness, and cohesiveness of starch-hydrocolloid complexes, and reduced the dehydration rate of complex gels. Dynamic rheological data showed that the energy storage modulus (G') was significantly higher than the loss modulus (G″). The magnitude of modulus increased with frequency, and elastic properties were better than viscous properties. Thermal analysis showed that hydrocolloids increased the starting temperature (To), and the final temperature (Tc). With addition of each of these four hydrocolloids, a more regular and porous thick-wall dense structure was formed, which effectively lowered kudzu starch's sensitivity to amyloglucosidase. It indicated that the binding of hydrocolloid to starch may slow down glucose release into blood during digestion. These results will help understand effects of natural hydrocolloid on kudzu starch, as well as expanding its application in food industry.

Starch modification through its combination with other molecules: Gums, mucilages, polyphenols and salts

Apart from its non-toxicity, biocompatibility and biodegradability, starch has demonstrated eminent functional characteristics, e.g., forming well-defined gels/films, stabilizing emulsions/foams, and thickening/texturizing foods, which make it a promising hydrocolloid for various food purposes. Nonetheless, because of the ever-increasing range of its applications, modification of starch via chemical and physical methods for expanding its capabilities is unavoidable. The probable detrimental impacts of chemical modification on human health have encouraged scientists to develop potent physical approaches for starch modification. In this category, in recent years, starch combination with other molecules (i.e., gums, mucilages, salts, polyphenols) has been an interesting platform for developing modified starches with unique attributes where the characteristics of the fabricated starch could be finely tuned via adjusting the reaction parameters, type of molecules reacting with starch and the concentration of the reactants. The modification of starch characteristics upon its complexation with gums, mucilages, salts, and polyphenols as common ingredients in food formulations is comprehensively overviewed in this study. Besides their potent impact on physicochemical, and techno-functional attributes, starch modification via complexation could also remarkably customize the digestibility of starch and provide new products with less digestibility.

Effects of Heat Treatment on the Structural and Functional Properties of Phaseolus vulgaris L. Protein

The paper presents the effect of heat treatment at 80 °C at different times (3, 5, 7, and 9 min) on the structural and functional properties of Phaseolus vulgaris L. protein (PVP, bean protein powder). Surface and structure properties of PVP after heat treatment were analyzed using a Fourier transform infrared spectrometer (FTIR), a fluorescence spectrophotometer, a visible light spectrophotometer, a laser particle size analyzer, and other equipment. The secondary structure and surface hydrophobicity (H0) of PVP changed significantly after heat treatment: the β-sheet content decreased from 25.32 ± 0.09% to 24.66 ± 0.09%, the random coil content increased from 23.91 ± 0.11% to 25.68 ± 0.08%, and the H0 rose by 28.96-64.99%. In addition, the functional properties of PVP after heat treatment were analyzed. After heat treatment, the emulsifying activity index (EAI) of PVP increased from 78.52 ± 2.01 m2/g to 98.21 ± 1.33 m2/g, the foaming ability (FA) improved from 87.31 ± 2.56% to 95.82 ± 2.96%, and the foam stability (FS) rose from 53.23 ± 1.72% to 58.71 ± 2.18%. Finally, the degree of hydrolysis (DH) of PVP after gastrointestinal simulated digestion in vitro was detected by the Ortho-Phthal (OPA) method. Heat treatment enhanced the DH of PVP from 62.34 ± 0.31% to 73.64 ± 0.53%. It was confirmed that heat treatment changed the structural properties of PVP and improved its foamability, emulsification, and digestibility. It provides ideas for improving PVP's potential and producing new foods with rich nutrition, multiple functions, and easy absorption.

The addition of crosslinked corn bran arabinoxylans with different gelling characteristics was associated with the pasting, rheological, structural, and digestion properties of corn starch

Crosslinked corn bran arabinoxylan (CLAX) is a food hydrocolloid that can be applied to improve the physicochemical and digestion properties of starch. However, the impact of CLAX with different gelling characteristics on starch properties remains elusive. Here, high cross-linked arabinoxylan (H-CLAX), moderate crosslinked arabinoxylan (M-CLAX), and low crosslinked arabinoxylan (L-CLAX) were fabricated to investigate their effects on the pasting, rheological, structural, and in vitro digestion property of corn starch (CS). The results showed that H-CLAX, M-CLAX, and L-CLAX differently increased the pasting viscosity and gel elasticity of CS, with H-CLAX exhibiting the greatest effect. The structural characterization of CS-CLAX mixtures showed that H-CLAX, M-CLAX, and L-CLAX differently enhanced the swelling power of CS and increased the hydrogen bonds between CS and CLAX. Furthermore, the addition of CLAX (especially H-CLAX) significantly reduced both the digestion rate and extent of CS, probably due to the increased viscosity and the formation of the amylose-polyphenol complex. This study provided new insights into the interaction between CS and CLAX, and could help to develop healthier foods with slow starch digestibility.

Effects of Heat-Moisture Treatment Whole Tartary Buckwheat Flour on Processing Characteristics, Organoleptic Quality, and Flavor of Noodles

The effects of heat-moisture treatment whole tartary buckwheat flour (HTBF) with different contents on the pasting properties and hydration characteristics of tartary buckwheat noodle mix flour (TBMF), dough moisture distribution, cooking properties, texture properties, and flavor of noodles were studied. The results showed that the optimal additional amount of HTBF is determined to be 40%. The peak viscosity, trough viscosity, breakdown value, and final viscosity decreased significantly, and the optimal cooking time of the noodles decreased with increasing HTBF. Compared with the sample without HTBF, HTBF addition increased the water absorption of the sample and decreased its water solubility. When the amount of HTBF >30%, the content of strongly bound water in dough increased significantly; at HTBF >40%, the water absorption and cooking loss of noodles increased rapidly, and the hardness of noodles was decreased; and with HMBF addition at 60%, the chewiness, resilience, and elasticity decreased. Moreover, HMBF addition reduced the relative content of volatile alkanes, while increasing the amount of volatile alcohols. HTBF addition also elevated the content of slow-digesting starch (SDS) and resistant starch (RS) in noodles, providing noodles with better health benefits in preventing chronic diseases. These results proved the possibility of applying heat-moisture treatment grains to noodles, and they provide a theoretical basis for the research and development of staple foods with a hypoglycemic index.

Physical modification of maize starch by gelatinizations and cold storage

The effects of gelatinization at three selected temperatures (DSC characteristic peaks temperature: TO, TP, and TC) and subsequent cold storage (CS) treatment on structural characteristics, pasting, and rheological properties of maize starch (MS) were investigated. The pasting, rheological properties of MS was changed with the increase of gelatinization temperature from TO to TC, but were not further significantly changed if the gelatinization temperature was higher than TC. Pasting and thermal properties analysis suggested that gelatinization at TC (TC treatment) significantly increased the gelatinization and pasting temperature of MS. Moreover, TC treatment decreased breakdown viscosity by 8.49 times and setback viscosity by 2.53 times. Dynamic rheological measurements revealed that the TC treatment caused the lower G' and G" of MS, and decreased the thickening coefficient by 55.17 %. These results indicated that TC treatment could enhance the thermal stability properties of MS, inhibiting the shear and short-term retrogradation, the shear-thinning behavior of MS. Interestingly, the CS treatment further inhibited the shear and short-term retrogradation and the shear-thinning behavior of MS. The leaked starch molecules aggregate to form a harder structure after gelatinization and starch molecules were further aggregated after CS treatment, these all were hypothesized to be responsible for these results.

Development of low glycemic index instant Phirni (pudding) mix-its visco-thermal, morphological and rheological characterization

High amylose rice (HAR) and carboxymethyl cellulose (CMC) are the preferred choices for enhancement of resistant starch content and lowering of glycemic index in dairy desserts. The effects of different levels of skimmed milk powder (SMP): HAR flour (45:55 to 75:25) and CMC (0.1 to 1%) were investigated on physical characteristics of dry-mix and on texture profile parameters, resistant starch (RS), predicted glycemic index (pGI), glycemic load (GL) and overall acceptability of phirni (a traditional milk pudding). Design expert predicted SMP (70): HAR (30) and CMC (0.8%) as optimum levels for reducing the pGI and maximizing the RS content and other quality characteristics in phirni. RS content of phirni (4.38%) prepared from optimized dry-mix (ODM) was higher while pGI (48.12) and GL (7.50) were lower as compared to phirni prepared from market dry-mix (MDM). The visco-thermal properties of ODM and MDM also showed significant variations. Storage modulus (Gʹ) and loss modulus (Gʹʹ) indicated that ODM phirni was less solid than MDM phirni. Scanning electron micrographs showed fused structures in ODM, while coarse sheet like structures were observed across the surface of MDM. Thus, ODM can be a promising substitute for the available milk desserts for diabetic patients.

Modification of starch by polysaccharides in pasting, rheology, texture and in vitro digestion: A review

Starch is a copolymer with unique physicochemical characteristics, is known for its low cost, easy degradability, renewable and easy availability. However, natural starches have some undesirable properties such as poor solubility, poor functional properties, lower resistant starch content with reduced retrogradation, and poor stability under various temperatures, pH, which limit their application in food. Different modification methods are used to improve its performance and expand its application. Numerous studies have been conducted to investigate why the addition of small amounts of polysaccharides affects the properties of starch pastes and gels. The application of polysaccharide-modified starch can be seen in the pasting, rheology, texture and in vitro digestive properties of starch gels. The main influencing factors include different starches, different specific polysaccharides, and different methods of preparation of composite pastes and gels. This paper reviews the changes in the properties of starch in terms of pasting, rheology, texture and in vitro digestion after modification with polysaccharides and the mechanism of polysaccharide action on starch.

Effect of Resistant Starch Sources on the Physical Properties of Dough and on the Eating Quality and Glycemic Index of Salted Noodles

The aim of this study was to evaluate the characteristics and eating quality of salted noodles that are incorporated with different formulations of flour. Up to 20% of wheat flour was substituted by composite flours of highly resistant starches, including heat moisture treatment corn starch (HMT-CS), high-amylose corn starch (Hylon VII), and green banana flour (GBF). The physical properties of dough, in conjunction with the eating quality and estimated glycemic index (EGI) of cooked salted noodles, were investigated in this study. The results concluded that the incorporation of GBF, HMT, and Hylon VII not only affected the water absorption and mixing tolerance of the dough, but also the maximum resistance to extension and extensibility in terms of the extensographic properties. Meanwhile, GBF, HMT, and Hylon VII incorporation significantly increased the resistant starch content and decreased the fat content of the noodle samples. The textural profile analyses of cooked salted noodles indicated that hardness, gumminess, chewiness, and shearing force increased; nevertheless, springiness declined with the increase in the proportion of flours from 10 to 20%. The sensory evaluation detected that wheat flour composited with 10% GBF and HMT flours could produce acceptable quality noodles as compared with normal typical control noodles. In the meantime, salted noodles incorporated with GBF, HMT-CS, and Hylon VII flour decreased the estimated glycemic index (EGI) dramatically. The result of this study concluded that incorporation of various sources of resistant starch flour could develop a low-GI noodle with good acceptability that may contribute to gastrointestinal health.

Complexation between burdock holocellulose nanocrystals and corn starch: gelatinization properties, microstructure, and digestibility in vitro

Holocellulose nanocrystals (hCNCs), with hydrodynamic diameters (D_Z) ranging from about 600 to 200 nm, were prepared by treating burdock insoluble dietary fiber (IDF) with enzymes and ultrasonic power. It was revealed that hCNCs improved the viscosity of corn starch (CS) during pasting and inhibited its short-term retrogradation. Besides, the crystallinity, short-range order of the double helix, viscoelastic properties, and microstructure compactness of CS gels improved remarkably in the presence of burdock hCNCs. These effects were both size- and dose-dependent, which primarily originated from the hydrogen bonding between hCNCs and amylopectin or leached amylose. In this regard, the digestion of CS gels containing hCNCs was remarkably retarded because of the reduced accessibility of digestive enzymes to the glycosidic bonds. Therefore, burdock hCNCs, prepared from natural resources using green techniques, hold potential applications in functional foods of a low glycemic index.

Understanding relations between rheology, tribology, and sensory perception of modified texture foods

The aim of this work was to examine relations between instrumental and sensory parameters in a texture modified food matrix, with and without saliva. Nine pureed carrot samples (eight thickened and a control) were developed with starch (0.4 and 0.8% wt/wt), xanthan (0.2 and 0.4% wt/wt) or starch-xanthan blends that met International Dysphagia Diet Standardisation Initiative (IDDSI) Level 4 guidelines using fork and spoon tests. Rheological and tribological tests were conducted on the food and simulated bolus prepared by adding fresh stimulated saliva to the food (1:5, saliva:food) to mimic oral processing. Perceived sensory properties were identified using a temporal dominance of sensations (TDS) test (n = 16) where panelists were given a list of nine attributes. The area under the curve was extracted from TDS curves for each attribute/sample and this was correlated with rheological (viscosity at 10 s^-1 , G', G″, and tan δ at 1 Hz) and tribological (friction coefficient in three regimes) data. The viscosity of the control sample decreased after adding hydrocolloids (except Starch_0.8%) and with saliva incorporation. G' and G″ either increased or were similar for xanthan and blends and decreased for starch-thickened samples. Hydrocolloid addition increased friction for all samples and was higher with saliva addition. Sensory results showed that samples with starch were perceived as thick and grainy while xanthan was perceived as smooth and slippery. A greater number of sensory attributes correlated with viscoelastic parameters compared to friction coefficients. Correlations were highest with the saliva added samples, further highlighting the importance of including saliva during instrumental testing.

Estimation of viscosity and hydrolysis kinetics of corn starch gels based on microstructural features using a simplified model

Viscosity is an important rheological property, which may have impact on the glycemic response of starchy foods. However, the relationship between starch gels viscosity on its hydrolysis has not been elucidated. The aim of this work was to assess the effect of gels viscosity on the microstructure, and the kinetics of enzymatic hydrolysis of starch. Corn starch gels were prepared from starch:water ratios varying from 1:4 to 1:16. A structural model was proposed that correlated (R-square = 0.98) the porous structure (cavity sizes, thickness walls) of gels and its viscosity. Kinetics constants of hydrolysis decreased with increasing starch content and consequently with gel viscosity. Relationships of viscosity with the microstructural features of gels suggested that enzyme diffusion into the gel was hindered, with the subsequent impact on the hydrolysis kinetics. Therefore, starch digestibility could be governed by starch gels viscosity, which also affected their microstructure.

In vitro digestion and structural properties of rice starch modified by high methoxyl pectin and dynamic high-pressure microfluidization

The rheological, structural properties and in vitro digestibility of starch with high methoxyl pectin (HMP) and further modified by dynamic high-pressure microfluidization (DHPM) were investigated. The viscosity and elasticity increased on addition of HMP and were more pronouncedly affected by 10% HMP. However, after DHPM treatment, the viscosity and elasticity decreased with increasing DHPM pressure. After 100 MPa DHPM treatment, the ordered and crystalline structures were further increased compared with starch-HMP mixtures. A compact and dense surface of starch paste was formed under 100 MPa DHPM and 10% HMP treatment, thus significantly slowing down the digestibility. In contrast, the crystalline and semicrystalline structure of starch were disrupted by intense shear force under 200 MPa DHPM. This study provides theoretical information regarding starch-HMP interaction and improves their functional and physicochemical properties through a promising strategy for better applications in food formulation.

Structural changes of A-, B- and C-type starches of corn, potato and pea as influenced by sonication temperature and their relationships with digestibility

The effect of sonication temperature on the structures and digestion behaviour of corn starch (CS, A-type), potato starch (PtS, B-type), and pea starch (PS, C-type) was investigated. For CS, sonication temperature resulted in a rough surface, decreased apparent amylose content, gelatinization enthalpy and gelatinization degree, increased short-range orders, long-range orders, retrogradation degree and resistant starch content. For PtS, sonication temperature led to a coarser surface with scratches, increased apparent amylose content and gelatinization degree, decreased short-range orders, long-range orders, gelatinization enthalpy, retrogradation degree, and resistant starch content. For PS, sonication temperature showed partial disintegration on surface, increased gelatinization degree, decreased apparent amylose content, short-range orders, long-range orders, gelatinization enthalpy, retrogradation degree and resistant starch content. This study suggested that starch digestion features could be controlled by the crystalline pattern of starch used and the extent of sonication temperature, and thus were of value for rational control of starch digestion features.

Effect of starch-hydrocolloid complexes with heat-moisture treatment on in vivo digestibility

The purpose of this study was to investigate the effect of starch-hydrocolloid (gum arabic, xanthan gum, and guar gum) complexes with heat-moisture treatment (HMT) on in vivo digestibility. In vivo digestibility experiments revealed that the body weight, liver weight, and fat index of mice in the intervention group were significantly reduced compared with those in the high-fat group. Glucose tolerance improved, and blood lipid levels, liver and adipose tissue morphology returned to normal. The results of mRNA expression levels showed that the intervention of corn starch-hydrocolloid complexes after HMT down-regulated the expression level of genes related to fat synthesis compared with the high-fat group, which could decrease lipid deposition and stabilize blood lipid levels. Results revealed that starch-xanthan gum complex (1 : 40 ratio) with HMT could markedly reduce the digestibility of starch. Overall, this study provides new ideas for the application of low-glycemic-index and functional foods.

Changes in structural, digestive, and rheological properties of corn, potato, and pea starches as influenced by different ultrasonic treatments

Ultrasound was widely used in starch modification, whereas there was no review focusing on the effects of different ultrasonic treatments on A-, B- and C-type starches. In this study, the effects of ultrasonic power (UP, 100-600 W) and ultrasonic time (UT, 5-35 min) on structural, digestibility and rheology of corn starch (CS), potato starch (PtS), and pea starch (PS) were investigated. As a result, UP and UT decreased the apparent amylose content of CS and PS, while increased the apparent amylose content of PtS. UP and UT enhanced R1047/1022 values of CS, whereas those of PtS and PS were decreased. Moreover, UP and UT decreased the gelatinization enthalpy of CS, PtS and PS. In vitro digestion revealed that UP and UT decreased the resistant starch content of PtS and PS, but increased the resistant starch content of CS. Rheological tests indicated that UP and UT decreased the flow behavior index of CS, PtS and PS pastes, and caused an increase in storage modulus and loss modulus. Results revealed that ultrasonic treatment represented a promising technology to obtain CS, PtS and PS with tailored digestibility and rheology, which allowed the texture and glycemic response of starch-based products to be adjusted.

Structural Features and Digestibility of Corn Starch With Different Amylose Content

In this study, the in vitro digestibility of corn starch with different amylose content was determined. The results showed that waxy corn starch (WCS) and corn starch (CS) have the highest digestibility, while high amylose corn starch (HACS) has a higher content of resistant starch (RS). Besides being related to amylose content, RS content is also closely related to particle shape, debranched fine structure, molecular structure, and semi-crystalline structure. HACS can maintain a complete particle structure after gelatinization and enzymolysis; differential scanning calorimetry showed a positive correlation between gelatinization enthalpy and RS content. As the amylose content increased, the content of fa (DP 6–12) decreased, while the content of fb2 (DP 25–36) and fb3 (DP ≥ 37) increased, which in-turn decreased the cluster polymer formed by short branch chains, and the formation of more hydrogen bonds between long chain branches improved starch stability. D, which characterizes the compactness of starch semi-crystalline structure, increased with the increase of RS content. HACS 60 with the highest RS content had a unique surface fractal structure between 7.41 < d (2π/q) < 10.58 nm, indicating that the dense structure is effective in maintaining the RS content.

Two 1,4-α-glucan branching enzymes successively rearrange glycosidic bonds: A novel synergistic approach for reducing starch digestibility

Enzymatically rearranging α-1,4 and α-1,6 glycosidic bonds in starch is a green approach to regulating its digestibility. A two-step modification process successively catalyzed by 1,4-α-glucan branching enzymes (GBEs) from Rhodothermus obamensi STB05 (Ro-GBE) and Geobacillus thermoglucosidans STB02 (Gt-GBE) was investigated as a strategy to reduce the digestibility of corn starch. This dual GBE modification process caused a reduction of 25.8 % in rapidly digestible starch fraction in corn starch, which were more effective than single GBE-catalyzed modification with the same duration. Structural analysis indicated that the dual GBE modified product contained higher branching density, more abundant short branches, and shorter external chains than those in single GBE-modified product. These results demonstrated that a moderate Ro-GBE treatment prior to starch gelatinization caused several suitable alterations in starch molecules, which promoted the transglycosylation efficiency of the following Gt-GBE treatment. This dual GBE-catalyzed modification process offered an efficient strategy for regulating starch digestibility.

Effects of acid hydrolysis on the evolution of starch fine molecular structures and gelatinization properties

Effects of acid hydrolysis on amylose molecular structures and their relations to starch gelatinization properties were investigated. First-order kinetics models were applied to fit the evolution curve of starch chain-length and molecular size by acid hydrolysis treatment. Results showed that a single hydrolysis phase was involved in the degradation of waxy maize starch chains, while two distinct phases existed for the degradation of maize, high amylose maize and sago starch chains. The fast hydrolysis phase involved degradation of amylose chains with DP > ~300 and amylopectin long intra-cluster branches, while amylose chains with DP < ~300 was involved in the slow hydrolysis phase. Amylose molecules with DP ~ 300 were proposed to impact starch gelatinization properties by interaction with cut-off amylopectin double helices and formation of amylose crystallites/entanglements. This study could help food industry precisely control amylose molecular structures by acid hydrolysis treatment to develop starchy foods with desirable properties.

Combination treatment of bamboo shoot dietary fiber and dynamic high-pressure microfluidization on rice starch: Influence on physicochemical, structural, and in vitro digestion properties

The physicochemical, structural properties and digestibility of rice starch treated by bamboo shoot dietary fiber (BSDF) combined with dynamic high-pressure microfluidization (DHPM) were investigated. Compared with starch modified by BSDF alone, the combination treatment decreased the pasting viscosity and viscoelasticity of starch. Furthermore, the pasting viscosity and viscoelasticity showed an increase from 50 to 100 MPa and then decreased after increasing the pressure to 150 and 200 MPa. The enthalpy of gelatinization and relative crystallinity of starch treated by BSDF and 100 MPa DHPM significantly increased by 17% and 63%, respectively. Scanning electron microscopy images demonstrated that flaky BSDF coated on starch granules to form a protective layer. As a result, the fractions of resistant starch increased and the starch hydrolysis extent and rate decreased under 100 MPa DHPM. This study highlights an innovative and promising strategy for improving the properties of starch and facilitating its utilization.

Recent advances in heat-moisture modified cereal starch: Structure, functionality and its applications in starchy food systems

Cereals, one of the starch sources, have a tremendous and steady production worldwide. Starchy foods constitute the major part of daily calorie intake for humans. As a simple and green modification approach, heat-moisture treatment (HMT) could change the granular surface characteristics and size, crystalline and helical structure, as well as molecular organization of cereal starch. The changing degree is contingent on HMT parameters and botanical origin. Based on the hierarchical structure, this paper reviews functionalities of heat-moisture modified cereal starch (HMCS) reported in latest years. The functionality of HMCS could be affected by co-existing non-starch ingredients through non-covalent/covalent interactions, depolymerization or simply attachment/encapsulation. Besides, it summarizes the modulation of HMCS in dough rheology and final food products' quality. Selecting proper HMT conditions is crucial for achieving nutritious products with desirable sensory and storage quality. This review gives a systematic understanding about HMCS for the better utilization in food industry.

Insight into the biphasic transition of heat-moisture treated waxy maize starch through controlled gelatinization

Biphasic transition is an important behavior of starch caused by heat-moisture treatment (HMT). Starch may change from typical single endotherm to biphasic endotherm (G1, G2) by HMT which corresponded to two viscosity peaks (PV₁ and PV₂) in pasting analysis. During PV₁, remarkable disruption of birefringence occurred in the inner region of starch granules, accompanied by a decreased relative crystallinity from 20.59 to 14.73%. Native starch completely lost their birefringence at 73 °C, while the HMT starch still showed strong birefringence in granule periphery. The HMT starch only lost crystallites at 80 °C (PV₂). A crystallite stability hypothesis was developed that G1 was mainly due to the gelatinization of the inner crystalline lamellae of starch granule, and the newly formed G2 was caused by the peripheral ones enhanced by HMT. This work also provided details on the mechanism of HMT and a potential method for the thermal transition study on starch.