Starch re-crystallization kinetics as a function of various cations

Effect of cation valence on the retrogradation, gelatinization and gel characteristics of maize starch

This study aimed to examine the impact of trivalent, divalent, or monovalent cations dissolving into water and being mixed with maize starch to influence its retrogradation, gelatinization, and gel characteristics. The result of the analysis using a differential scanning calorimeter showed that all cations raised the peak of gelatinization temperature of maize starch, especially Al3+ or Fe3+, while trivalent cations reduced the enthalpy. The result of the analysis using a rapid viscosity analyzer showed that trivalent cation caused lower trough viscosity, final viscosity, and pasting temperature but higher breakdown viscosity of maize starch than monovalent or divalent cations. Confocal laser scanning microscopy showed that the cation promoted the destruction of gelatinized maize starch granules, especially Zn2+, Fe3+, or Al3+. Additionally, trivalent Fe3+ or Al3+ caused higher gel strength of maize starch. Generally, the cation with higher valence changed more retrogradation, gelatinization, and gel characteristics of maize starch.

Development of High-Efficiency Fertilizer by Hydrogels Obtained from Cassava Starch and Citric Acid for Slow Release of Ammonium and Potassium

Fertilizers with enhanced efficiency or high-efficiency fertilizers increase the nutrient availability, minimize losses, and reduce costs, thereby increasing crop yields and food production while mitigating environmental impacts. This research evaluates the synthesis of biodegradable hydrogels from cassava starch and citric acid for agrochemical applications. Hydrogels were synthesized using water as the solvent and applied for the controlled release of macronutrients (N and K). Four concentrations of nutrient-containing salts were tested (0.5 to 10.0% w/w). Materials were analyzed using ATR-FTIR spectroscopy and swelling studies. The presence of nutrients reduced both the crosslinking efficacy and the water absorption capacity, with the latter dropping from 183.4 ± 0.6% to 117.9 ± 3.7% and 157.4 ± 25.0% for hydrogels loaded with NH4Cl and KCl, respectively. The cumulative release of K and N from the hydrogel was monitored for 144 h and examined using kinetics models, revealing that the releases follow Fickian's diffusion and anomalous diffusion, respectively. Additionally, the material was formed using cassava with peel previously milled to reduce the production costs, and its potential for nutrient-controlled delivery was evaluated, with the finding that this hydrogel decreases the release rate of nitrogen. The results suggest that these biomaterials may have promising applications in the agrochemical industry in the making of high-efficiency fertilizers.

Understanding starch gelatinization and rheology modeling of tapioca starch- NaCl/CaCl2 blends: Thermodynamic properties and gelatinization reaction kinetics during pre- and post-ultrasonication

The presence of salt can impact the fluid phase and gelatinization process of starch granules. The variation in viscosity and rheology models including the Herschel-Bulkley, the Casson model, and the power law, were determined by adding salts before and after starch ultrasonication. Non-isothermal kinetics can be utilized for the mathematical modeling of the gelatinization process and the evolution of the reaction. Unlike Na+ ions, Ca+2 ions notably elevate viscosity. The Casson model accurately predicts viscosity data. Results indicate that the addition of Na+ ions decreases yield stress by up to 60.4 %, while Ca+2 ions increase by up to 100.8 %. Adding Na+ ions decreases the required thermal energy by as much as 49.6 %, while the presence of Ca+2 ions can lead to a substantial increase of up to 337.1 % compared to control samples. The positive ∆G indicates a non-spontaneous gelatinization process. The addition of NaCl promotes a spontaneous reaction, while the addition of CaCl2 increases the Gibbs energy. The changes in entropy are minimal, implying minimal changes in starches' disorder structure.

Changing the ionic strength can regulate the resistant starch content of binary complex including starch and protein or its hydrolysates

Ionic strength condition is a crucial parameter for food processing, but it remains unclear how ionic strength alters the structure and digestibility of binary complexes containing starch and protein/protein hydrolysates. Here, the binary complex with varied ionic strength (0-0.40 M) was built by native corn starch (NS) and soy protein isolate (SPI)/hydrolysates (SPIH) through NaCl. The inclusion of SPI and SPIH allowed a compact network structure, especially the SPIH with reduced molecule size, which enriched the resistant starch (RS) of NS-SPIH. Particularly, the higher ionic strength caused the larger nonperiodic structures and induced loosener network structures, largely increasing the possibility of amylase for starch digestion and resulting in a decreased RS content from 19.07 % to 15.52 %. In other words, the SPIH hindered starch digestion while increasing ionic strength had the opposite effect, which should be considered in staple food production.

Effects of cation valence on swelling power, solubility, pasting, gel strength characteristics of potato starch

The objective of this study was to investigate the effects of monovalent, divalent and trivalent cations on the physicochemical properties of potato starch. Cations decreased the water absorption in potato starch granules to cause lower swelling power, especially 0.02-0.04 mmol/g Fe3+ or 0.01-0.04 mmol/g Al3+, but 0.01 mmol/g trivalent cation led more amylose dissolving into the water to cause higher solubility. High concentration of divalent or trivalent cations markedly decreased the viscosity in potato starch paste during further heating and cooling, resulting in the decreases of the trough and finial viscosity, especially 0.04 mmol/g Fe3+. Higher valence of cations decreased the gel strength in potato starch, especially 0.02-0.04 mmol/g Fe3+ or Al3+. Higher valence of cations decreased the starch gel binding with the water and caused lower water holding capacity. In general, a higher valence of cations caused more changes in the physicochemical characteristics of potato starch.

Effect of Lithium Salts on the Properties of Cassava Starch Solid Biopolymer Electrolytes

This study evaluates the effect of lithium salts on the structural, electrochemical, and thermal properties of cassava starch solid biopolymer electrolytes (SBPEs). Films of SBPEs were synthesized using plasticizing agents and lithium salts (LiCl, Li2SO4, and CF3LiSO3) via thermochemical method. The SBPEs with lithium salts exhibited characteristic FTIR bands starch, with slight variations in the vibration oxygen-related functional groups compared to salt-free biopolymer spectra. The RCOH/COC index (short-range crystallinity) was higher in the films synthesized without lithium salt and the lowest value was established in the films synthesized with Li2SO4. Thermal degradation involved dehydration between 40 to 110 °C and molecular decomposition between 245 to 335 °C. Degradation temperatures were close when synthesized with salts but differed in films without lithium salt. DSC revealed two endothermic processes: one around 65 °C linked to crystalline structure changes and the second at approximately 271 °C associated with glucose ring decomposition. The electrochemical behavior of the SBPEs varied with the salts used, resulting in differences in the potential and current of peaks from the redox processes and its conductivity, presenting the lowest value (8.42 × 10-5 S cm-1) in the SBPE films without salt and highest value (9.54 × 10-3 S cm-1) in the films with Li2SO4. It was concluded that the type of lithium salt used in SBPEs synthesis affected their properties. SBPEs with lithium triflate showed higher molecular ordering, thermal stability, and lower redox potentials in electrochemical processes.

Thermal, Rheological, Structural and Adhesive Properties of Wheat Starch Gels with Different Potassium Alum Contents

Wheat starch (WS) is a common adhesive material used in mounting of calligraphy and paintings. Potassium alum (PA) has indeed been used for many centuries to modify the physicochemical properties of starch. Thermal analysis revealed that the presence of PA led to an increase in the gelatinization temperature and enthalpy of the starch gels. The leached amylose and the swelling power of the starch gels exhibited a maximum at the ratio of 100:6.0 (WS:PA, w/w). The rheological properties of starch gels were consistent with changes in the swelling power of starch granules. SEM observations confirmed that the gel structure became more regular, and the holes grew larger with the addition of PA below the ratio of 100:6.0 (WS:PA, w/w). The short-range molecular order in the starch gels was enhanced by the addition of PA, confirmed by FT-IR analysis. Mechanical experiments demonstrated that the binding strength of the starch gels increased with higher PA concentrations and decreased significantly after the aging process. TGA results revealed that PA promoted the acid degradation of starch molecules. This study provides a detailed guide for the preparation of starch-based adhesive and its applications in paper conservation.

Effect of rice protein on the gelatinization and retrogradation properties of rice starch

In this study, rice starch (RS) was mixed with varying amounts of rice protein (RP; 0 % to 16 %) to explore the effects of protein on the gelatinization and retrogradation of starch during storage. The increased RP addition decreased the viscosity and gelatinization enthalpy of the mixtures but caused an upward trend in the gelatinization temperature, indicating that protein hampers the process of starch gelatinization. Furthermore, RP addition reduced gel hardness, decreased retrogradation enthalpy and crystallization rate constant, but increased Avrami exponent upon RS retrogradation. RP addition also facilitated the mobility of water molecules, weakened the conversion from bound water to free water in the gels, and moderately increased the uniformity and thickness of gel shape. In summary, RP had a dose-dependent effect on the gelatinization and retrogradation behavior of RS, although the anti-retrogradation concentration effect strongly weakened at protein levels exceeding 12 %. It is noteworthy, that excessive RP addition resulted in disulfide bond formation, which increased gel strength and network structure but reduced the ability of RP to facilitate water molecule mobility and restrict water migration, ultimately reducing its anti-retrogradation capability. This phenomenon can be partially attributed to spontaneous protein-protein interaction caused by excessive protein addition, replacing the starch-protein interaction.

Characterizing digestibility of potato starch with cations by SEM, X-ray, LF-NMR, FTIR

Cations can combine with starch and alter its physicochemical characteristics. The addition of cations may influence the in vitro digestion of potato starch. Scanning electron microscopy, X-ray diffraction, low-field nuclear magnetic resonance, and Fourier transform infrared spectroscopy were used to measure the microstructure, relative crystallinity, water distribution, and interaction of potato starch with cations and characterize its digestibility. The results showed that all cations decreased rapidly digestible starch (RDS) at a low concentration but increased the RDS with the addition of cations, especially trivalent cations. However, the resistant starch (RS) had the opposite trend. All cations increased the relative crystallinity of potato starch, except Ca²⁺. Fe³⁺, and Al³⁺ markedly decreased the mobility and hydrogen bonds in potato starch. In general, the addition of cations influenced the retrogradation of potato starch, resulting in a change in its digestibility.

Effects of three glutenins extracted in acidic, neutral and alkaline urea solutions on the retrogradation of wheat amylose and amylopectin

Three glutenins (glutenin 1, glutenin 2, and glutenin 2) were extracted in acidic, neutral and alkaline urea solutions respectively. All of the three glutenins are rich in glutamic acid (Glu, >30 %) and proline (Pro, >20 %). Glutenin 1, extracted at pH 5, shows higher contents of hydrophilic amino acids as serine (Ser, 5.25 %), aspartic acid (Asp, 2.99 %), tyrosine (Tyr, 3.11 %), arginine (Arg, 2.09 %) and threonine (Thr, 2.11 %) than the other two glutenins. The retrogradation of three glutenins with amylose/amylopectin indicated that glutenin 1 showed significant inhibition effect on the retrogradation of wheat amylose. The characterizations of amylose retrograded with glutenin 1 by FT-IR, XRD, DSC and solid ¹³C NMR showed that new hydrogen bonds between Glu, Tyr and wheat amylose were formed, which prevented the formation of hydrogen bonds between amylose themselves. Glycosidic bonds between some hydroxyl groups of C6 in wheat amylose and certain hydroxyl groups of Ser and Thr in glutenin with specific chain length were present. The macromolecules with steric hindrance prevented the rearrangement of amylose into regular crystals. The retrogradation of wheat amylose was inhibited in this way. This study provides a key targeting step to control the retrogradation of amylose.

Modulation of the self-assembly kinetics and digestibility of type 3 resistant starch particles by co-crystallization with amino acid

The effect of eight different l-amino acids (L-AA) on type-3 resistant starch particles (rSPs) derived from short chain glucan (SCG) was investigated. The L-AA were categorized based on their charge and polarity. The results reveal that positively charged L-AA, such as lysine and arginine, decreased the nucleation and growth rate of rSPs, while non-charged L-AA have negligible effects. Negatively charged L-AA, such as glutamic acid and aspartic acid, had a significant impact on the morphology and crystallinity of the rSPs, resulting in particle size of around 3 μm and crystallinity of around 35%. This implies that charged L-AA influence the arrangement of SCG double helices in the particles. Furthermore, the complexation of SCG with charged L-AA reduced the level of RS in rSPs, indicating that L-AA could be useful in modulating the physical properties and digestibility of rSPs.

Batter Characteristics and Oil Penetration of Deep-Fried Breaded Fish Nuggets: Effect of Wheat Starch—Gluten Interaction

To understand the effect of the interaction between wheat starch ( $\mathrm{W}\mathrm{S}$ ) and wheat gluten ( $\mathrm{W}\mathrm{G}$ ) on batter characteristics and oil penetration of deep-fried breaded fish nuggets, batters were prepared using a $\mathrm{W}\mathrm{S}$ and $\mathrm{W}\mathrm{G}$ blend at the ratios of 15 : 1, 13 : 1, 11 : 1, 9 : 1, and 7 : 1 $\mathrm{w}/\mathrm{w}$ , respectively, and batter-breaded fish nuggets (BBFNs) were fried at 170°C for 40 s followed by 190°C for 30 s. Moisture adsorption isotherms of $\mathrm{W}\mathrm{S}$ and $\mathrm{W}\mathrm{G}$ , viscosity, rheological behavior, and calorimetric properties of the batters were measured, and pick-up of BBFNs, thermogravimetric properties of the crust, and oil transport were investigated. The moisture absorption capacity of $\mathrm{W}\mathrm{G}$ was higher than $\mathrm{W}\mathrm{S}$ at a low water activity (0.04–0.65), while the opposite trend was observed at a highwater activity (0.65–0.88). As the proportion of $\mathrm{W}\mathrm{S}$ decreased, the viscosity, $G”$ and tan δ of batter, pick-up of BBFNs, temperature and enthalpy change (ΔH) of protein denaturation and $\mathrm{W}\mathrm{S}$ gelatinization, and oil penetration of BBFNs during deep-fat frying, which are decreased until reaching a minimum value at the ratio of 11 : 1 $\mathrm{w}/\mathrm{w}$ , then increased ( $p<0.05$ ). However, G' of batter and thermogravimetry temperatures of crust exhibited the opposite trend. These results proved that the $\mathrm{W}\mathrm{S}$ – $\mathrm{W}\mathrm{G}$ interaction significantly affected the batter characteristics and oil penetration of BBFNs during deep-fat frying, which can be used to guide the manufacturing of low-fat fried BBFNs.

Tailormade Wheat Arabinoxylan Reveals the Role of Substitution in Regulating Gelatinization and Retrogradation Behavior of Wheat Starch

To elucidate the role of substitution of arabinoxylan (AX) in the characteristics of wheat starch, this study prepared AX with a well-defined structure by targeted enzymatic hydrolysis and comparatively investigated the effects of AX with different degrees of substitution on gelatinization and retrogradation behavior of starch. Removal of major arabinofuranosyl (Araf) of mono- or disubstituted xylopyranosyl (Xylp) of both low-molecular-weight (Mw: 62.5 kDa, Araf/Xylp: 0.61) and high-molecular-weight AX (Mw: 401.2 kDa, Araf/Xylp: 0.61) reversed the decreased gelatinization viscosity and recrystallization of amylose induced by AX to a similar extent. Upon retrogradation for 30 days, the Araf of mono- and disubstituted Xylp contributed to the water distribution and the effect depended on the molecular chain length. The C3-linked Araf of disubstituted Xylp was more involved in prohibiting the retardation of recrystallization of amylopectin, while the presence of Araf of monosubstituted Xylp might hinder the interactions between AX and amylopectin.

Research on the influences of two alcohol soluble glutenins on the retrogradation of wheat amylopectin/amylose

Two alcohol soluble glutenins (ASGLUs) were extracted from gluten and further separated by column chromatography. The ASGLUs with Mw lower than 20,000 (ASGLU 1) and Mw higher than 70,000 (ASGLU 2) show the total amino acid contents of 86.71 g/100 g and 62.847 g/100 g respectively. Both of them are rich in Glu (45.574% and 43.224%) and Pro (15.447% and 16.370%) while poor in cys-s, met and lys (less than 1%). When wheat amylopectin/amylose retrogrades with those ASGLUs, the retrogradation rate of amylopectin with ASGLU 1 enhances significantly. UV-Vis, X-ray diffraction, FT-IR, DSC, CD and solid ¹³C NMR suggest that the double helixes of amylopectin short-chain branching are unwound during gelatinization. The hydrogen bonds of ASGLU 1 between amide and carbonyl oxygen are destroyed, meanwhile, β-sheets are unfolded. During retrogradation, ASGLU 1 with less steric hindrance gets into the crevice of amylopectin and combines with the short-chain branching by hydrogen bond. The retrogradation dynamics show that the nucleation type of amylopectin-ASGLU 1 changes from instantaneous to rod-like growth during the process of retrogradation. β-sheet of ASGLU 1 changes to β-turn and random conformations at the meantime. The results provide a key targeting to control retrogradation of dough.

Effect of hyperbranched poly(trimellitic glyceride) paired with different metal ions on the physicochemical properties of starch

The novel hyperbranched poly(trimellitic glyceride) (PTG) starch plasticizer synthesized in our previous study was neutralized with different alkaline metal hydroxides. Mixed with starch, the effects of different alkaline metal cations, M⁺, on gelatinization of starch suspensions and thermal behaviors of the films were analyzed using RVA and DMA, respectively. The structures of the starch suspensions, films and freeze-dried samples (S/PTG-M) were investigated using DSC, XRD and FTIR spectroscopy, respectively. M⁺ increased the gelatinization temperature of starch suspensions in the order of S/PTG-Li > S/PTG-Na > S/PTG-K. The formation of a complex between M⁺ and starch in the films observed using FTIR spectroscopy improved the stability of the starch paste and gel, and increased the gel temperature of starch dispersions. The corresponding starch gel was relatively thermostable, but not shear-resistant. PTG decreased the T_g of starch films with different paired M⁺. PTG-Li and PTG-K, but not PTG-Na, strengthened the mechanical properties of starch films.

Impact of water extractable arabinoxylan with different molecular weight on the gelatinization and retrogradation behavior of wheat starch

Water-extractable arabinoxylan (WEAX) could effectively improve the cereal food quality, while its regulatory effect on wheat starch properties has yet to be well-understood. This study selected the WEAX with different molecular weight (Mw) but same branched degree, and comparatively investigated their effects on the gelatinization and retrogradation behavior of wheat starch. The decreased degree of swelling power, solubility and peak viscosity suggested that low Mw WEAX (L-WEAX) could hinder starch gelatinization more evidently compared with high Mw WEAX (H-WEAX), due to the pronounced inhibition effect on amylose leaching and amylose-lipid complex formation. L-WEAX suppressed the recrystallization of amylose and thus the short-term retrogradation. However, H-WEAX mainly retarded the recrystallization of amylopectin, exerting a more significant inhibition effect on the long-term retrogradation. This study could provide a theoretical basis for enhancing the quality and extending the shelf life of starchy foods by selecting the optimum structure of WEAX.

Characterizing the impact of starch and gluten-induced alterations on gelatinization behavior of physically modified model dough

Gelatinization properties of physically modified starch-gluten matrices are often exclusively traced back to starch constitution without considering the state of gluten. Thus, gelatinization of model dough, combining reference (rS)/modified starch (mS) with reference (rG)/modified gluten (mG), was investigated using nuclear magnetic resonance and differential scanning calorimetry to relate structural alterations of biopolymers to their hydration properties. No differences were found in gelatinization onsets of model dough consisting of rS and mS combined with mG (starch: gluten = 50:50 (m/m)), although gelatinization enthalpy of mS mG (1.7 ± 0.4 J/g dm) was significantly lowered in comparison to rS mG (2.2 ± 0.2 J/g dm). Relaxation time T₂ was significantly reduced for mG in comparison to rG, demonstrating a tighter water binding of mG. This suggests that reduced gelatinization enthalpy of modified starch-gluten matrices is caused by a destruction of crystal parts of modified starch and by a tighter water binding of modified gluten.

Concentration dependent rate constants of sodium substitute functionalities during wheat dough development

Chloride salts can serve as sodium chloride (NaCl) substitutes in wheat dough for sensory or technological reasons. Therefore, the effect of different substitutes on wheat dough development during mixing (optimum water absorption, dough development time, stability) and fermentation (maximum dough height) with a material-adapted water addition and mixing time were investigated. The substitutes had effects on all measures at a level of 2 g salt 100 g^-1 wheat flour, with the exception of KCl. The intensity of the effect significantly followed the Hofmeister series due to an altered hydration behavior of the structure-determining gluten proteins. The experiments were supported by CLSM micrographs combined with image analysis. Next to an absolute substitution, the main focus of the study were concentration dependent functionalities of the chloride salts. Therefore, concentration dependent rate constants were calculated based on the application of different concentration levels of the chloride salts. These rate constants showed in all cases a similar tendency following the Hofmeister series.

Effects of low molecular sugars on the retrogradation of tapioca starch gels during storage

The effects of low molecular sugars (sucrose, glucose and trehalose) on the retrogradation of tapioca starch (TS) gels stored at 4°C for different periods were examined with different methods. Decrease in melting enthalpy (ΔHmelt) were obtained through differential scanning calorimetry analysis. Analysis of decrease in crystallization rate constant (k) and increase in semi-crystallization time (τ1/2) results obtained from retrogradation kinetics indicated that low molecular sugars could retard the retrogradation of TS gels and further revealed trehalose as the best inhibitor among the sugars used in this study. Fourier transform infrared (FTIR) analysis indicated that the intensity ratio of 1047 to 1022 cm-1 was increased with the addition of sugars in the order of trehalose > sucrose > glucose. Decrease in hardness parameters and increase in springiness parameters obtained from texture profile analysis (TPA) analysis also indicated that low molecular sugars could retard the retrogradation of TS gels. The results of FTIR and TPA showed a consistent sugar effect on starch retrogradation with those of DSC and retrogradation kinetics analysis.