Starch Retrogradation Research Articles

Corn starch and methylcellulose edible films incorporated with fireweed (Chamaenerion angustifolium L.) extract: Comparison of physicochemical and antioxidant properties

The properties of edible films derived from corn starch (CS) and methylcellulose (MC) supplemented with fireweed extract (FE; 0.0125-0.05% w/w) were analyzed. Due to their more crystalline structure, the MC films were significantly stronger (~26 MPa) than the CS films (~4 MPa). In turn, CS produced films with lower water vapor permeability (WVP, 50.12-51.74 vs. 56.52-59.10 g mm m−2 d−1 kPa−1). The hydrothermally-disrupted starch granules contributed to high roughness and opacity of the CS films. The FE-supplemented films exhibited an intensive yellow color and improved the UV-absorbing effect. FE delayed starch retrogradation, as indicated by the reduced crystallinity and slightly improved transparency of the CS films. Incorporation of FE significantly enhanced the released radical scavenging activity (RSA) of the films, while did not affect the WVP and mechanical properties. Due to better FE-trapping capacity, the CS-based films exhibited lower antioxidant activity (RSA60min = 2.21-19.75%) as compared to the MC counterparts (RSA60min = 4.87-38.31%).

Consecutive reaction kinetics model reveals the nature of long-term rice amylopectin retrogradation characteristics

Starch retrogradation involves nucleation and crystal growth steps, while their relative contribution to the overall retrogradation kinetics and relations with starch fine molecular structures have not been elucidated. In this study, a consecutive reaction kinetics model (CRK) was developed to fit long-term retrogradation kinetics curves for 10 rice starches with distinct molecular structures. Starch chain-length distributions (CLDs) and melting enthalpy kinetics curves for these starches were obtained from our published data. It was shown that these melting enthalpy kinetics curves can be satisfactorily deconvoluted by the CRK model into a combination of nucleation and crystal growth curves. Correlation analysis between CRK model-fitted parameters with starch CLDs showed that starch retrogradation nucleation and crystal growth steps were controlled by distinct starch fine molecular structures. These results have practical applications, as it enables a separate regulation of nucleation and crystal growth steps during retrogradation process of starch-based foods for desirable nutritional properties.

Pasting Behavior and Viscoelastic Properties of Fresh, Chilled, and Rehydrated Freeze-Dried Gel Beads from Blends of Tapioca Flour, Soy Flour, and Cane Sugar

Abstract An extreme vertices design for a mixture of three components was used to establish the proportions of tapioca flour (50% to 100% w/w), soy flour (0% to 50% w/w), and cane sugar (0% to 10% w/w) mass fractions in a food gel bead system. Thus, nine compositions were prepared and analyzed. The pasting profiles of the mixtures were studied using a Rapid Visco Analyzer. The texture profiles of fresh, chilled, and rehydrated freeze-dried gel beads were studied using a texture analyzer. Increasing the proportion of soy flour in the range of 11.25% to 50.00% w/w decreased the peak viscosity, breakdown, final viscosity, and setback of mixed flour. Tapioca flour in the proportion of 81.25% to 100.00% w/w recorded the lowest hardness of fresh gel beads (92.00 to 283.00 g). Soy flour in the proportion of 11.25% to 50.00% w/w exhibited lower texture profiles (hardness, chewiness, and gumminess) than tapioca flour in gel beads for both chilled and rehydrated freeze-dried gel beads. Significant relationships were found among pasting profiles of the flour mixtures and texture profiles of fresh, chilled, and rehydrated freeze-dried gel beads, implying a functional role for soy flour in food gel beads. In conclusion, soy flour can act as an anti-retrogradation agent for the gel beads both in chilled (stored at 4°C for 7 days) and freeze-dried conditions. A small amount of cane sugar does not affect the inhibition of starch retrogradation in the gel bead system. Keywords: Anti-retrogradation, Food gel bead, Pasting profile, Soy flour, Tapioca flour, Texture profiles

The retrogradation characteristics of starch in green wheat product Nianzhuan: effects of storage temperature and time

Abstract The objective of this study was to reveal the process of starch retrogradation and quality changes of Nianzhuan stored at 4, −18 °C, and freeze-thaw cycles treatment for different lengths of time. XRD revealed that Nianzhuan starch displayed an increasing trend of crystallinity with prolonged storage time and numbers of freezing-thawing cycles, which was likely due to a more orderly crystalline matrix in starch. The Raman full width at half-maximum (FWHM) of the bands at 2913 cm−1 of the three storage methods all decreased. According to DSC analysis, an increase in ∆H was detected, and a significant (P < 0.05) increase in T o and T p were found at −18 °C, and freeze-thaw treated samples, indicating more thermal energy were needed to disrupt re-crystallization. Good correlations between crystallinity, FWHM, ∆H, and hardness, springiness, chewiness were tested. The results of this study would provide useful information for the process of starch-based product Nianzhuan.

Wheat rheological and Mixolab quality in relation to cropping systems and plant nutrition sources

The objective of this study was to evaluate the effect of cropping systems [integrated (INT) vs. organic (ORG)] and plant nutrition sources (synthetic in INT vs. approved organic in ORG) on analytical and rheological quality traits of winter wheat and its productivity. The results after 16 years of field experiments were evaluated. Pre-crop for winter wheat was N-fixing crop. Grain yield of winter wheat (6.8 t ha<sup>–1</sup> in INT, 6.5 t ha<sup>–1</sup> in ORG) did not differ significantly, while plant nutrition sources had an equal and positive effect on the yield. Crude protein quantity was higher in INT system by about 0.2%. The farinograph dough development time and dough stability were the longest for ORG and fertilised treatments. Mixolab quality indicators showed a clear distinction between ORG and INT systems and fertilisation in the protein and starch characteristics of the grain. The ORG reported longer Mixolab stability of the dough, mainly on fertilised treatment (8.8 min). Starch characteristics – torque C4 (amylolytic activity) and torque C5 (starch retrogradation) were higher for ORG system. Torque C2, protein weakening, was not affected by the cropping system. ORG system has the potential to achieve consistent, high-quality yields with significantly lower reliance on external inputs.

Influence of inulin–konjac suspension as a fat replacer in baked muffins and its impact on textural and oxidative stability upon storage

In this study, vegetable oil in the muffins’ formulation was substituted with inulin–konjac (IK) suspensions (in the ratio of 70:30) at 30, 45, 60, and 75% concentration. Muffins formulated with higher IK concentrations (IK60 and IK75) showed a lower increase in hardness after storage (51% and 48%). By the end of storage, lipid peroxidation was lower in all reduced-fat muffins, with up to a 49% reduction seen in the IK30 muffin. The addition of IK suspension greatly improved the nutritional profile of the reduced-fat muffins significantly and demonstrated efficacy in delaying lipid oxidation, and starch retrogradation during prolonged storage. These findings suggest that functional muffins with reduced fat and increased dietary fiber can be produced using IK suspensions. Although the use of inulin in baked goods is well documented, there are limited studies that explore the possible use of konjac glucomannan (KGM) in baked products. Novelty impact statement Vegetable oil was substituted with a combination of inulin and konjac glucomannan. An improvement in the overall nutritional profile for reduced-fat muffins. Reduced-fat muffins showed a delay in lipid oxidation and starch retrogradation.

Biosynthesis, structure and functionality of starch granules in maize inbred lines with different kernel dehydration rate

In this study, we report important relationships between kernel starch and kernel dehydration rate for eight maize inbred lines with different dehydration characteristics. High-throughput RNA sequencing data of starch biosynthesis-related genes showed that kernel moisture content and dehydration rate were both associated with differential expression of most starch biosynthetic genes. Especially, kernel moisture content was positively correlated with the increased expression of SBEI and SBEIIb, thereby potentially inducing biosynthesis of amylose with low molecular weight and amylopectin with low content of amylopectin chains with degree of polymerization (DP) 6-12 in inbred lines with fast kernel dehydration rate. We found a negative correlation between short amylopectin chains (DP 6-12) and the starch retrogradation rate. Hence, a low amount of amylopectin chains with DP 6-12 in the inbred lines with fast kernel dehydration rate was a plausible reason for their high short- and long-term retrogradation.

Impact of Roasted Yellow Split Pea Flour on Dough Rheology and Quality of Fortified Wheat Breads.

Roasted yellow split pea (YSP) flours were used to substitute wheat flour, at 10–20% (flour basis) in wheat bread formulations. Rheometry showed that roasted YSP flour addition increased elasticity and resistance to deformation and flow of the composite doughs, particularly at 20% substitution; instead, at 10% addition (either raw or roasted YSP flour), there were no effects on dough rheology and bread textural properties. Breads fortified with roasted YSP flour at levels >10% exhibited lower loaf-specific volume and harder crumb compared to control (bread without YSP flour). Moreover, only breads with 20% roasted YSP flour displayed a significantly higher staling extent and rate, compared to control, as assessed by large deformation mechanical testing and calorimetry (starch retrogradation) of crumb preparations. This formulation also showed a large increase in β-sheets and β-turns at the expense of α-helix and random coil conformations in protein secondary structure as assessed by FTIR spectroscopy. Roasting of YSP effectively masked the “beany” and “grass-like” off-flavors of raw YSP flour at 10% substitution. Overall, roasted YSP flour at the 10% level was successfully incorporated into wheat bread formulations without adversely affecting dough rheology, bread texture, and shelf-life, resulting in final products with a pleasant flavor profile.

The impact of starchy food structure on postprandial glycemic response and appetite: a systematic review with meta-analysis of randomized crossover trials

ABSTRACTBackgroundStarchy foods can have a profound effect on metabolism. The structural properties of starchy foods can affect their digestibility and postprandial metabolic responses, which in the long term may be associated with the risk of type 2 diabetes and obesity.ObjectivesThis systematic review sought to evaluate the clinical evidence regarding the impact of the microstructures within starchy foods on postprandial glucose and insulin responses alongside appetite regulation.MethodsA systematic search was performed in the PUBMED, Ovid Medicine, EMBASE, and Google Scholar databases for data published up to 18 January 2021. Data were extracted by 3 independent reviewers from randomized crossover trials (RCTs) that investigated the effect of microstructural factors on postprandial glucose, insulin, appetite-regulating hormone responses, and subjective satiety scores in healthy participants.ResultsWe identified 745 potential articles, and 25 RCTs (n = 369 participants) met our inclusion criteria: 6 evaluated the amylose-to-amylopectin ratio, 6 evaluated the degree of starch gelatinization, 2 evaluated the degree of starch retrogradation, 1 studied starch–protein interactions, and 12 investigated cell and tissue structures. Meta-analyses showed that significant reductions in postprandial glucose and insulin levels was caused by starch with a high amylose content [standardized mean difference (SMD) = −0.64 mmol/L*min (95% CI: −0.83 to −0.46) and SMD = −0.81 pmol/L*min (95% CI: −1.07 to −0.55), respectively], less-gelatinized starch [SMD = −0.54 mmol/L*min (95% CI: −0.75 to −0.34) and SMD = −0.48 pmol/L*min (95% CI: −0.75 to −0.21), respectively], retrograded starch (for glucose incremental AUC; SMD = −0.46 pmol/L*min; 95% CI: −0.80 to −0.12), and intact and large particles [SMD = −0.43 mmol/L*min (95% CI: −0.58 to −0.28) and SMD = −0.63 pmol/L*min (95% CI: −0.86 to −0.40), respectively]. All analyses showed minor or moderate heterogeneity (I2 < 50%). Sufficient evidence was not found to suggest how these structural factors influence appetite.ConclusionsThe manipulation of microstructures in starchy food may be an effective way to improve postprandial glycemia and insulinemia in the healthy population. The protocol for this systematic review and meta-analysis was registered in the international prospective register of systematic reviews (PROSPERO) as CRD42020190873.

Effects of Laminaria japonica polysaccharides on the texture, retrogradation, and structure performances in frozen dough bread

Bread staling is a deterioration process that causes serious economic losses in the food industry. The objective of this research was to determine the impact of Laminaria japonica polysaccharides (LJP) on the anti-staling properties during storage. The baking, thermal, starch retrogradation, and microstructure properties of bread with LJP during room storage were investigated. The results showed that the addition of LJP improved specific volume and textural properties. The kinetic model showed that the addition of LJP decreased the rate constant. Meanwhile, LJP addition exhibited a significant decrease of enthalpy and crystallization in the frozen dough bread. Data also showed that LJP may form more hydrogen bonds and interfere the starch reassociation and retrogradation. This effect was also evident in the microstructure, showing that LJP could improve the fresh quality and delay the deterioration of the bread structure. Overall, LJP can potentially be used as an effective natural additive to increase the storage stability of baked food.

Retrogradation of sweet potato amylose and amylopectin with narrow molecular weight distribution

AbstractRetrogradation of sweet potato amylose and amylopectin with narrow molecular weight distribution at different temperatures was investigated by X‐ray diffraction (XRD). Atomic force microscope (AFM), scanning electron microscope (SEM) and light microscopy were combined to study the morphology of the molecular assemblies during retrogradation. Avrami equation was used to the retrogradation kinetics the of above starches by determining the crystallinity and the ratio of peak area of two distinctive peaks. It was found that only the ratio of peak area/total area at 2θ = ~16.3° could represent the crystallinity of retrograded starch‐containing amorphous regions. Considering the crystallinity as retrogradation rate, only the retrogradation kinetics of sweet potato amylose could be analysed by Avrami equation, but not the amylopectin’s. All Avrami exponents n of amyloses at any temperatures were less than 1.0, indicating instantaneous nucleation and rod‐like growth. AFM results showed that the maximum heights of layered structure for sweet potato amylose, amylopectin and blending of both were approximately 4800, 180 and 200 nm, respectively. The height of the former two decreased during storage, but the height of blending remained unchanged. Amylose served as nuclei of amylopectin during starch retrogradation.

Effects of Poloxamer Content and Storage Time of Biodegradable Starch-Chitosan Films on Its Thermal, Structural, Mechanical, and Morphological Properties.

Biodegradable packaging prepared from starch is an alternative to fossil-based plastic packaging. However, the properties of starch packaging do not comply with the necessary physicochemical properties to preserve food. Hence, in a previous study, we reported the preparation of a composite polymer material based on starch-chitosan-pluronic F127 that was found to be an adequate alternative packaging material. In this study, we modified the physicochemical properties of this material by storing it for 16 months under ambient conditions. The results indicate that the incorporation of pluronic F127 in the blend polymer can help avoid the retrogradation of starch. Moreover, at higher concentrations of pluronic F127, wettability is reduced. Finally, after storage, the materials exhibited surface modification, which is related to a color change and an increase in solubility, as well as a slight increase in stiffness.

Structural and Thermal Properties of Starch Plasticized with Glycerol/Urea Mixture

The paper presents the results of research on the influence of used plasticizing system on the structural and thermal properties of thermoplastic starch (TPS). The thermoplastic starch granulate was obtained by extrusion of native starch in the presence of a plasticizing system using a twin-screw extruder. Glycerol and urea were used as plasticizers in various proportions. In order to evaluate the effectiveness of the starch plasticization process, changes in its chemical structure were analyzed by infrared spectroscopy (FTIR), gel permeation chromatography (GPC) and X-ray diffraction (XRD). TPS thermal stability was determined by thermogravimetric analysis (TGA). An improvement in the efficiency of the plasticization process has been found for a urea-containing plasticizing system compared to the composition of starch plasticized only with glycerol. In addition, the XRD analysis confirms the beneficial effect of urea on the inhibition of starch retrogradation process.

Effects of insoluble dietary fiber and ferulic acid on the rheological properties of dough

This study sought to investigate the effects of insoluble dietary fiber (IDF), ferulic acid (FA), and a combination of the two (IDF + FA) on the rheological properties of dough. When the amount of IDF was increased from 2 g to 12 g, the water absorption rate of the dough increased by 14.33%. However, when FA within the dough was in the range of 61.6%–63.1%, the dough's water absorption rate was lower than that of the control sample, which might be related to FA inducing the breakdown of the dough. The dough that included IDF was associated with a higher stability time, a higher C2, and a lower development time due to the dilution effect of IDF, which weakened the gluten but increased the mechanical resistance of the dough. FA not only reduced the dough's development time and stability, but also reduced its C2 due to the crosslinking reaction with gluten. Moreover, IDF reduced the gelatinization properties of the starch and the stability of the hot-formed gel. In addition, it inhibited starch retrogradation in the dough. Due to the strong water absorption and filling effects of IDF, the elastic modulus (G′) and viscous modulus (G″) of the dough increased, although the creep strain decreased. The effects of the IDF + FA combination might be due to the crosslinking reaction of IDF-FA and IDF-FA-gluten, which reduced the plasticizing effect of the water, further increased the viscoelasticity and reduced the creep strain of the dough.

Effects of konjac glucomannan on the long-term retrogradation and shelf life of boiled wheat noodles.

Starch retrogradation and moisture migration of boiled wheat noodles (BWNs) result in quality deterioration and short shelf life. The objective of this research was to investigate whether konjac glucomannan (KGM) could improve the quality of BWNs and further establish the shelf-life prediction model. The moisture distribution, recrystallization, and thermal properties of BWNs during refrigerated or ambient temperature storage were determined. Low-field nuclear magnetic resonance data showed that KGM addition induced left-shifts of T21 and T22 values, indicating that KGM limited the mobility of bound and immobile water among noodle matrices. X-ray diffraction spectra revealed that KGM did not change the crystal patterns of BWNs but could inhibit the starch recrystallization after refrigerated storage. The Tp and ΔH values of retrograded samples notably (P < 0.05) decreased with the increase of KGM addition, suggesting the hinderance of starch retrogradation behavior by KGM. The shelf life of BWNs was predicted by accelerated storage test combined with the Arrhenius equation. The present data displayed that the predicted shelf life of vacuum-packed and sterilized BWNs with 10g kg-1 KGM at 25 °C was 733 days, 2.4-fold that of the control group. BWNs with KGM addition could inhibit starch retrogradation and improve the storage stability, consequently promoting noodle quality. © 2021 Society of Chemical Industry.

Influence of Retrogradation on KI–Starch Visualization of Reactive Oxygen Species Emitted by Plasma Jets

Plasma jets have been widely researched in the fields of medicine, biology, and agriculture and their positive effects were reported. To understand the working mechanism of plasma-target interaction, the spatial distribution of reactive oxygen species (ROS) at the target's surface should be examined as they are considered to be the most affectable factor to treat the target. The authors have used KI-starch method in the form of gel or liquid, which uses reactions among potassium iodide, starch, water, and oxidative species, to visualize the distribution of ROS. This method gives information regarding the distribution of ROS by coloration; however, the retrogradation of starch possibly influences on the visualization especially in a liquid KI-starch reagent. In this article, the visualization on the distribution of ROS was done via the liquid KI-starch reagent during plasma jets' irradiation with different helium gas flow rates from 1 to 4 L/min. The retrogradation of starch was confirmed when the gas flow rate was higher than 3 L/min, because the reagent's surface was cooled down, which incapacitated the ability of coloration from the reagent. It was revealed that a ring-like coloration pattern could be observed at the gas flow rate of 3 L/min, because the coloration occurred at the outside of an uncolored circular region where the retrogradation of starch was formed by the gas flow and insensitive to ROS.

Comparison of the Grain Quality and Starch Physicochemical Properties between Japonica Rice Cultivars with Different Contents of Amylose, as Affected by Nitrogen Fertilization

In order to determine the effects of nitrogen fertilizer on the grain quality and starch physicochemical properties of japonica rice cultivars with different contents of amylose, normal amylose content (NAC) and low amylose content (LAC) cultivars were grown in a field, with or without nitrogen fertilizer (WN). The relationships between the amylose content, starch physicochemical properties and eating quality were also examined. Compared with WN, nitrogen fertilizer (NF) significantly increased the grain yield but markedly decreased the grain weight. In addition, the processing quality tended to improve, but the appearance quality and eating quality deteriorated under NF application. The grain yield was similar between NAC and LAC cultivars. However, the grain quality and starch physicochemical properties were significantly different between NAC and LAC cultivars. The palatability of the cooked rice was significantly higher in the LAC than in NAC cultivar, which was due to its lower amylose content, protein content, hardness, and retrogradation enthalpy and degree, and its higher stickiness, peak viscosity, breakdown, relative crystallinity and peak intensity. The amylose content and protein content were significantly negatively correlated with the palatability. The amylose content was significantly positively correlated with the final viscosity and setback, and was significantly negatively correlated with the relative crystallinity, peak intensity, gelatinization enthalpy and breakdown. Palatability was significantly positively correlated with peak viscosity, breakdown and peak intensity, and was significantly negatively correlated with the final viscosity, setback, and retrogradation enthalpy and degree. Therefore, the selection of a low amylose content japonica rice cultivar grown without nitrogen fertilizer can reduce the amylose and protein contents, as well as improving the pasting properties, starch retrogradation properties and eating quality of the cooked rice.

Study on inhibition effects and mechanism of wheat starch retrogradation by polyols

Effects and mechanism of polyols (mannitol, isomalt or xylitol) on the retrogradation of wheat starch (WS) were investigated by rapid viscosity analysis (RVA), rheological properties, fourier-transform infrared spectroscopy (FTIR), low-field nuclear magnetic resonance (LF-NMR), texture profile analysis (TPA), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) in this study. A decrease in peak viscosity, trough viscosity, breakdown, final viscosity and setback of WS was observed with addition of polyols. The storage modulus (G′) and the change rate of G′ in the presence of polyols were significantly reduced. The number of hydrogen bonds increased accordingly and polyols in starch gel could combine with more water and reduce water migration. After 4 weeks storage at 4 °C, the hardness, retrogradation enthalpies (△H), crystallization rate constant (k) and relative crystallinity (RC) of WS/polyols were significantly reduced compared with those of the blank. Hence, polyol was promising to be a useful additive to inhibit the retrogradation of wheat starch, which provided a reference for inhibiting the retrogradation of starch-containing food.

Long-term retrogradation behavior of lotus seed starch-chlorogenic acid mixtures after microwave treatment

The effect of microwave treatment on the long-term retrogradation behavior of lotus seed starch (LS)-chlorogenic acid (CA) binary mixtures (LS-CA) was evaluated. The dielectric properties of LS-CA enhanced its microwave energy conversion capacity and the related heating effect, compared with LS. Changes in the chain length distribution (CLD) induced by microwave treatment revealed that the cleavage of internal B2 and B3 amylopectin chains was greater in LS-CA. Low-field nuclear magnetic resonance (LF-NMR) analysis showed that CA increased the water-holding capacity and stability of starch gels. Moreover, differential scanning calorimetry (DSC) and analysis of long- and short-range ordered structures indicated that CA inhibits the alignment of disordered starch polymers during retrogradation, especially the re-formation of the helical conformation. These findings significantly increase our understanding of the mechanism by which polyphenols inhibit starch retrogradation after microwave treatment. This understanding should facilitate the development of starchy foods with tailored retrogradation rates and properties.

Effects of Pectins with Different Structural and Conformational Characteristics on Gelatinization and Retrogradation of Corn Starch

AbstractIn this study, the effects of pectin with different structural and conformational characteristics on gelatinization and retrogradation of corn starch are investigated. The structural characteristics analysis showed that the low, medium, and high methoxyl pectin have different molecular weights (4.93×105, 2.59×105, and 3.26×105 Da), branched structures, and intrinsic viscosity (651.11, 641.99, and 1003.30 mL g−1). Pasting properties analysis results demonstrate that the presence of pectin retarded starch gelatinization, and high methoxyl pectin with branched structure affect the viscosity of starch pastes. Furthermore, the presence of high methoxyl pectin changes the viscoelastic property and limits the retrogradation of starch gel significantly. Correlation analysis suggests that the intrinsic viscosity is the major factor regulating the effect of pectin on gelatinization and retrogradation of starch. This study provides a theoretical basis for further in‐depth use of pectin in starchy food.