Starch Recrystallization Research Articles

Effects of rice bran soluble dietary fiber on the physicochemical properties of frozen dough and the quality of steamed bread

The effects of rice bran soluble dietary fiber (RBSDF) on the physicochemical properties of frozen dough and the quality of steamed bread were investigated. Moderate levels of RBSDF (145 and 165 μg/g) reinforced the dough rheological properties and increase the contents of the disulfide bonds, while higher levels (185 and 205 μg/g) adversely affected the rheological properties and the contents of the disulfide bonds. Microstructure observation showed that the frozen dough with adding 145 and 165 μg/g RBSDF had more uniform pores and fewer exposed starch granules. A series of quality assessments showed that the moderate levels of RBSDF (145 and 165 μg/g) inhibited the starch recrystallization of frozen dough, and steamed breads from their frozen dough showed the increase in the sensory quality and antioxidant properties. When 145 μg/g RBSDF was added to dough, the steamed bread from its frozen dough gained the highest sensory evaluation score and the highest antioxidant activity, and had higher specific volume and lower water loss. Our studies suggest that the RBSDF can be utilized to develop the frozen dough products for improving their nutritional quality.

Modifying Cassava Starch via Extrusion with Phosphate, Erythorbate and Nitrite: Phosphorylation, Hydrolysis and Plasticization.

Extrusion processing of plasticized cassava starch, a prominent industrial crop, with chemical additives offers a thermo-mechanical approach to modify starch structures through physical and chemical interactions. This research investigates the interaction and morphology of thermoplastic cassava starch (TPS) blended with tetrasodium pyrophosphate (Na4P2O7), sodium tripolyphosphate (Na5P3O10), sodium hexametaphosphate (Na6(PO3)6), sodium erythorbate (C6H7O6Na), and sodium nitrite (NaNO2) via twin-screw extrusion. The effects of these additives on the chemical structure, thermal profile, water absorption, and solubility of the TPS were examined. The high temperature and shearing forces within the extruder disrupted hydrogen bonding at α-(1-4) and α-(1-6) glycosidic linkages within anhydroglucose units. Na4P2O7, Na5P3O10 and Na6(PO3)6 induced starch phosphorylation, while 1H NMR and ATR-FTIR analyses revealed that C6H7O6Na and NaNO2 caused starch hydrolysis. These additives hindered starch recrystallization, resulting in higher amorphous fractions that subsequently influenced the thermal properties and stability of the extruded TPS. Furthermore, the type and content of the added modifier influenced the water absorption and solubility of the TPS due to varying levels of interaction. These modified starch materials exhibited enhanced antimicrobial properties against Escherichia coli and Staphylococcus aureus in polyester blends fabricated via extrusion, with nitrite demonstrating the most potent antimicrobial efficacy. These findings suggest that starch modification via either phosphorylation or acid hydrolysis impacts the thermal properties, morphology, and hydrophilicity of extruded cassava TPS.

Insight into konjac glucomannan-retarding deterioration of steamed bread during frozen storage: Quality characteristics, water status, multi-scale structure, and flavor compounds

Konjac glucomannan (KGM), a water-soluble hydrocolloid, holds considerable potential in the food industry, especially for improving the quality and nutritional properties of frozen products. This study explored the alleviative effect of KGM on the quality characteristics, water status, multi-scale structure, and flavor compounds of steamed bread throughout frozen storage. KGM significantly improved the quality of steamed bread by slowing down the decrease in water content and the increase in water migration while maintaining softness and taste during frozen storage. Notably, KGM also delayed amylopectin retrogradation and starch recrystallization, thus preserving the texture and structure of the steamed bread. At week 3, the microstructure of the steamed bread with 1.0 % KGM remained intact, with the lowest free sulfhydryl content. Additionally, heat map analysis revealed that KGM contributed to flavor retention in steamed bread frozen for 3 weeks. These results indicate that KGM holds promise as an effective cryoprotectant for improving the quality of frozen steamed bread.

Structure and properties of starch - BaSO4 composite obtained using mechanical activation techniques

The aim of this study is to obtain and characterize starch films structurally modified by in situ precipitation of BaSO4 combined with mechanical activation of casting dispersion in a rotor-stator device. By the rheological method, it was found that the modification causes a decrease in the ability of casting dispersions to structure over time. Composite films with a filler content of 0 %–15 % (w/w) were characterized using optical and SEM microscopy, FT-IR spectroscopy, and tensile and moisture resistance testing data. The maximum increase in strength (by 70 %) and elongation at break (by 870 %) is achieved with a filler content of 5 % and 15 %, respectively. An increase in the filler content to 5 % causes an increase in starch recrystallization rate, but at concentrations above 5 % of BaSO4, it inhibits retrogradation. The films obtained by mechanical activation with optimized parameters were uniformly translucent, had lower water vapor permeability than films made from starch alone, had high flexibility, and did not warp or shrink. The developed high-performance, environmentally friendly method can be recommended for the large-scale production of starch-based composite materials.

Recrystallization of Cellulose, Chitin and Starch in Their Individual and Native Forms.

Semi-crystalline natural polymers are involved in many technological processes. Biopolymers having identical chemical compositions can differ in reactivity in heterogeneous transformations depending on their crystal structure (polymorphic modification). This paper compares the crystal structure recrystallization processes occurring in natural polysaccharides (cellulose, chitin, and starch) in the individual form and as a component of native biomass. Aqueous treatment of pre-amorphized semi-crystalline biopolymers was shown to result in swelling, thus alleviating the kinetic restrictions imposed on the restoration of crystalline regions and phase transition to the thermodynamically more stable polymorphic modification. During recrystallization, cellulose I in the individual form and within plant-based biomass undergoes a transition to the more stable cellulose II. A similar situation was demonstrated for α- and β-chitin, which recrystallize only into the α-polymorphic modification in the case of both individual polymers and native materials. Recrystallization of A-, B-, and C-type starch, both in the individual form and within plant-based flour, during aqueous treatment, results in a phase transition, predominantly to the B-type starch. The recrystallization process depends on the temperature of aqueous treatment; longer treatment duration has almost no effect on the recrystallization degree of polymers, both in the individual form and within native materials.

Preparation of Multi‐Grain Flour with High Content of Resistant Starch and the Mechanism Underlying the Improved Digestion Resistance

AbstractTo acquire the optimum treatment strategy that leads to the highest yield of resistant starch (RS) in multigrain flour (MF), wheat flour, whole oat flour, and whole buckwheat flour are used to prepare antidigestive MF by using pullulanase debranching combining heat–moisture treatment (P‐HMT). Based on the single factor tests and response surface analysis, the optimum conditions for the treatment of MF are determined as follows: pullulanase 62.6 U g−1, autoclaving 21.3 min, HMT at 100 °C, and 30.4% water content for 6.0 h. Under these conditions, the yield of RS in the flour reaches 77.42%. P‐HMT causes protein denaturation, starch gelatinization, and flour clumps in MF, facilitating starch recrystallization and interactions among short‐chain starch, monomeric proteins, and lipids. All these findings are further confirmed by the conversion of starch crystal from A‐type to B+V‐type, the improvement of starch short‐range molecular order, and the presence of more binary/ternary complexes in treated flour. In brief, the starch digestion resistance improvement in the treated flour is attributed to the recrystallization of short‐chain starch and interactions between starch and protein/lipid.

A multihole nozzle controls recrystallization of high-moisture extruded maize starches: Effect of cooling die temperature

Hot extrusion is utilized for starch modification due to its high mechanical input and product output. Amylose recrystallization commences and primarily depends on intermolecular interactions after conventional extrusion. Hence, the design of a new component based on the existed extrusion system was aimed at facilitating molecular aggregation, potentially accelerating starch recrystallization. In this study, a nozzle sheet comprising 89 holes was integrated into the cooling die. The impact of the multihole nozzle on the structure and in vitro digestibility of extruded maize starches after retrogradation was examined at varying cooling die temperatures. The results showed that the nozzle-assembled extrusion system operated effectively without additional mechanical or yield losses. At 50 °C, the crystallinity of nozzle-produced starch was approximately 70 % higher than that of conventionally extruded starch, predominantly owing to the B-type allomorph of the amylose double helix. Recrystallized amylopectin was also found in these nozzle-produced starches, indicating that multihole nozzle-induced uniaxial elongational flow resulted in the rapid starch crystallization. The increased formation of recrystallized amylose led to improved molecular order in starch structures while reducing their digestibility. These findings revealed a new approach to improve starch crystallinity by incorporating a nozzle sheet in the extrusion process.

Adding gamma-aminobutyric acid to modulate the in vitro digestive characteristics of tapioca pearls

The effects of gamma-aminobutyric acid (GABA) on gelatinization, pasting and rheological properties of the blend of hydroxypropyl distarch phosphate and tapioca starch were studied to examine the in vitro digestive characteristics of tapioca pearls. The addition of higher GABA contents resulted in lower starch hydrolysis rates and release rates of GABA during the digestion process, which indicated that GABA could modulate the digestive properties of tapioca pearls. RVA and DSC results showed that GABA inhibited the gelatinization of mixed starch and hindered the recrystallization of starch, leading to enhanced thermal stability and reduced viscosity. Also, the addition of GABA limited the water absorption and expansion of starch to some extent, resulting in decreased elastic and viscous moduli. XRD results showed that GABA changed the crystal structure of original mixed starch with reduced crystallinity. Moreover, the addition of GABA resulted in a reduction of RDS content and a significant increase in RS, which would provide potential applications for GABA in starchy health food.

Effect of Water Content on Rice Starch Gel during Retrogradation

AbstractWater content plays a crucial role in the retrogradation of rice starch. The relationship between the water content of rice starch gels and their structural changes during retrogradation is studied. The results indicate that the gels have three distinct types of water: structural constitution water, starch intermolecular bound water, and free water. The rate of retrogradation increases as the water content increases. Nevertheless, when the water content is lower (1:1) or higher (1:6) than optimal, the starch molecules show limited aggregation and recrystallization, which retards the rate of retrogradation. With the aggregation and recrystallization of starch and the inward contraction of the gel structure, the mobility of water is restricted, and the binding of water to the starch is enhanced. With the sustained contraction of the gel structure, the water‐holding capacity of the gel is weakened. By analyzing the experimental results, water distribution, transformation, and migration in rice starch during retrogradation are delineated. These findings provide a theoretical basis for controlling the retrogradation of rice starch and improving product quality.

Esterified wheat bran: Physicochemical properties, structure and quality improvement of Chinese steamed bread during refrigerated storage

To develop the application of wheat bran and improve the nutrition and anti-staling capacity of Chinese steamed bread (CSB), oleic acid-esterified wheat bran (OWB) was prepared by esterification of wheat bran with oleic acid, and its physicochemical properties, structure, and quality improvement for CSB during refrigerated storage were investigated. The hydrophilic-lipophilic balance value of OWB was 16.0, the maximum degree of substitution was 0.146, and its emulsifying capacity was similar to that of glycerol monostearate. The starch gelatinization degree of CSB containing 3 % OWB and the control decreased by 19.55 % and 27.12 % within 7 days of refrigerated storage, respectively, while the hardness of CSB with OWB was lower than that with wheat bran. OWB inhibited starch recrystallization and increased bound water in the corresponding CSB, which effectively delayed starch retrogradation. OWB had a positive emulsifying capacity and showed potential as a functional material for preventing retrogradation of starch-based foods.

Development and characterization of an active starch-based film as a chlorogenic acid delivery system

Given its health benefits for the human body, chlorogenic acid (CA) offers promising applications in the food industry. However, the instability and low bioavailability of CA remain to be solved. In this paper, a starch-based film prepared by the homogenization and solution-casting method was used as an effective carrier to alleviate these problems. Homogenization (10–50 MPa) reduced the starch paste viscosity and its particle sizes from 21.64 to 7.68 μm, which promoted the starch recrystallization and induced chemical cross-links between starch-CA, as confirmed by the FTIR result with an appearance of a new CO peak at about 1716 cm−1. Accordingly, the rapidly digestible starch content of the film was reduced to 27.83 % and the CA encapsulation efficiency was increased to 99.08 % (from 65.88 %). As a result, the film system extended CA's release time beyond 4 h and significantly increased the heat-treated CA's antioxidant activity. Besides, the tensile strength and elastic modulus of the film were also improved to 6.29 MPa (from 1.63 MPa) and 160.98 MPa (from 12.02 MPa), respectively, by homogenization. In conclusion, the developed active starch-based film could be used as an edible film for the production of functional food or active food packaging.

Potato starch plasticization by natural deep eutectic solvent

A natural deep eutectic solvent (NADES) based on choline chloride and malic acid was used to plasticize potato starch. The influence of starch gelatinization temperature, NADAES content and the method of its incorporation (before and after gelatinization) on starch plasticization was investigated. Polymer-plasticizer interactions were studied using MDSC, DMTA, XRD and FTIR-ATR methods. The viscosity of starch solutions as well as the mechanical properties and water absorption of the obtained films were determined. Gelatinization conditions had a significant impact on the viscosity of starch solutions and the physicochemical properties of the obtained films. The cross-linking reaction between starch and malic acid was confirmed by MDSC, DMTA, and mechanical properties. Slight recrystallization of starch was observed after 12 months of storage.

The interaction and physicochemical properties of the starch-polyphenol complex: Polymeric proanthocyanidins and maize starch with different amylose/amylopectin ratios

This study investigated the impact of polymeric proanthocyanidins (PPC) on the physicochemical characteristics of maize starch with varying amylose content, and their potential interaction mechanism. PPC with a lower content (1 %) reduced the viscoelasticity of the high amylose maize starch (HAM) system, inhibited amylose rearrangement, and enhanced its fluidity. However, excessive PPC restrained the interaction between PPC and amylose. In contrast to HAM, PPC improved the gelation ability of waxy maize starch (WAM) as PPC concentration was raised. PPC suppressed the recrystallization of starch during storage, and PPC had a superior inhibition influence on the retrogradation of WAM in comparison to HAM. This indicated that amylopectin was more likely to interact with PPC than amylose. Hydrogen bonds were the main driving force between PPC and starch chains, which was clarified by Fourier transform-infrared, nuclear magnetic resonance, X-ray diffraction, iodine bonding reaction, and dynamic light scattering data. Additionally, the mechanism of interaction between PPC and the two starch components may be similar, and variance in physicochemical attributes can be primarily credited to the percentage of amylose to amylopectin in starch.

Insight into microstructure evolution during starch retrogradation by infrared and Raman spectroscopy combined with two-dimensional correlation spectroscopy analysis

Starch retrogradation is a mechanism that is associated with the quality of starch-based food products; however, the molecular mechanisms underlying this process remain unclear. In this study, we analyzed starch recrystallization by measuring the degree of starch retrogradation, determining the retrogradation enthalpy, and performing scanning electron microscopy experiments. Two-dimensional correlation spectroscopy (2D-COS) was applied to Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy data to further characterize the starch-retrogradation process. We collected and preprocessed FTIR and Raman spectral data on 15 different storage days and then mapped these data using 2D-COS to analyze the ongoing composition changes in starch. Our FTIR- and Raman-2D-COS results revealed 11 and 10 quantitative peaks related to starch retrogradation, respectively. We analyzed the order of specific chemical composition and molecular changes by determining correlations between spectral variables and chemical components; moreover, using these quantitative peaks, we employed a quantitative partial least squares model to establish the degree of starch regeneration based on the retrogradation and associated enthalpy changes. The correlation coefficients of the validation set were 0.943 and 0.972, respectively. These data show that quantitative peaks obtained with 2D-COS analysis can be used to study starch retrogradation quantitatively and have implications for enhancing the quality of starch-based foods.

Effect of mulberry leaf polysaccharides on the physicochemical, rheological, microstructure properties and in vitro starch digestibility of wheat starch during the freeze-thaw cycles

Temperature fluctuation damages the quality of starch-based foods, and the freeze-thaw cycle (FTC) can simulate this process. This study investigated how Mulberry leaf polysaccharides (MLP) affect the freeze-thaw stability and digestibility of wheat starch (WS). During FTC, MLP reduced the syneresis and retarded the water migration of WS gel. Meanwhile, MLP delayed the recrystallization of starch, which reduced the enthalpy value and crystallinity of WS gel during FTC. The addition of MLP significantly reduced the hardness of WS gel. Furthermore, MLP could prevent the deterioration of the rheological characteristic and preserve the network structure of the WS gel. In addition, MLP boosted the resistant starch and decreased the fast-digesting starch content in the freeze-thaw gel. Our findings suggested that MLP could enhance the freeze-thaw stability of WS gel, decrease the starch digestibility, and be an effective component in improving the quality of wheat starch-based frozen food.

Effect of Freeze–Thaw Cycles on Physicochemical and Functional Properties of Ginger Starch

Ginger (Zingiber officinale Roscoe.) starch is a waste product generated during the extraction of bioactive compounds from ginger. This study aimed to treat ginger starch with different freeze–thaw cycles and explore the effect on the functional components, physicochemical properties, and structural properties of ginger starch. The results of the study showed that as the number of freeze–thaw cycles increased, the content of resistant starch, amylose, total starch, and recrystallization in ginger starch increased significantly (p < 0.05). Freeze-dried ginger starch exhibited a C-type crystal structure in the X-ray diffraction pattern. The Fourier-transform infrared spectroscopy results also showed that the value of A1047/1022 increased, indicating that the freeze–thaw cycle would increase the degree of starch recrystallization. In terms of physical and chemical properties, compared with gelatinized starch, freeze–thawed starch had low swelling power, high solubility, low peak viscosity and breakdown, indicating higher thermal stability. In conclusion, freeze–thaw treatment can promote the formation of resistant starch from ginger starch and reduce starch hydrolysis, reflecting the potential of low–GI foods. We hope that ginger starch can be used as a raw material for new applications in functional foods.

Retrogradation behavior of starch dough prepared from damaged cassava starch and its application in functional gluten-free noodles

A novel starch-based model dough used to exploit staple foods was demonstrated to be feasible, which was based on damaged cassava starch (DCS) obtained by mechanical activation (MA). This study focused on the retrogradation behavior of starch dough and the feasibility of its application in functional gluten-free noodles. Starch retrogradation behavior was investigated by low field-nuclear magnetic resonance (LF-NMR), X-ray diffraction (XRD), scanning electron microscope (SEM), texture profile and resistant starch (RS) content analysis. During starch retrogradation, water migration, starch recrystallization and microstructure changes were observed. Short-term retrogradation could significantly alter the texture properties of starch dough, and long-term retrogradation promoted the formation of RS. The damage level influenced starch retrogradation, and damaged starch with the increasing damage level was beneficial to facilitate the starch retrogradation. Gluten-free noodles made from the retrograded starch had acceptable sensory quality, with darker color and better viscoelasticity than Udon noodles. This work provides a novel strategy for the proper utilization of starch retrogradation for the development of functional foods.

Effects of thermal treatment on the microbial shelf-life and quality stability of wet instant cooked noodles during storage

Pasteurization, acidification followed by pasteurization, and autoclave extended the shelf-life of cooked noodles (groups S1, S2 and S3) to 3, 180 and 180 days, respectively. Pasteurization increased the hardness of cooked noodles from 53.60 to 58.01 N. However, the growth of thermoduric bacteria caused a decrease in pH, coloration, and hardness of group S1 during storage. Meanwhile, the pH and hardness of group S2 decreased to 4.42 and 39.22 N respectively, while hardness and chewiness increased during storage. In addition, physicochemical-textural characteristics of group S3 are maintained throughout storage. The hardness of groups S1 and S2 is related to the gluten structure. The compact gluten network formed after pasteurization. Meanwhile, acidification inhibited the polymerization of glutenin and gliadin. The starch melted after autoclave, masking the impact of the gluten network and decreasing hardness. During storage, hydrolysis of protein and starch by bacteria resulted in the deterioration of group S1. Recrystallization of starch resulted in the stiffening of group S2. The absence of metabolism of bacteria and presence of stable gluten in group S3 contributed to the stable starch structures, inducing its stable quality. Thermal treatment can be recommended as an effective additional treatment for producing shelf-stable wet instant cooked noodles.

Effect of Frozen Treatment on the Sensory and Functional Quality of Extruded Fresh Noodles Made from Whole Tartary Buckwheat.

Extruded noodles made from whole Tartary buckwheat are widely known as healthy staple foods, while the treatment of fresh noodles after extrusion is crucial. The difference in sensory and functional quality between frozen noodles (FTBN) and hot air-dried noodles (DTBN) was investigated in this study. The results showed a shorter optimum cooking time (FTBN of 7 min vs. DTBN of 17 min), higher hardness (8656.99 g vs. 5502.98 g), and less cooking loss (5.85% vs. 21.88%) of noodles treated by freezing rather than hot air drying, which corresponded to better sensory quality (an overall acceptance of 7.90 points vs. 5.20 points). These effects on FTBN were attributed to its higher ratio of bound water than DTBN based on the Low-Field Nuclear Magnetic Resonance results and more pores of internal structure in noodles based on the Scanning Electron Microscopy results. The uniform water distribution in FTBN promoted a higher recrystallization (relative crystallinity of FTBN 26.47% vs. DTBN 16.48%) and retrogradation (degree of retrogradation of FTBN 34.67% vs. DTBN 26.98%) of starch than DTBN, strengthening the stability of starch gel after noodle extrusion. FTBN also avoided the loss of flavonoids and retained better antioxidant capacity than DTBN. Therefore, frozen treatment is feasible to maintain the same quality as freshly extruded noodles made from whole Tartary buckwheat. It displays significant commercial potential for gluten-free noodle production to maximize the health benefit of the whole grain, as well as economic benefits since it also meets the sensory quality requirements of consumers.

Biodegradable Active Packaging Material Containing Grape Seed Ethanol Extract and Corn Starch/κ-Carrageenan Composite Film.

An active film composed of corn starch/κ-carrageenan and ethanolic grape seed extract (0, 1, 3, and 5 wt% of GSE on corn starch basis) were successfully prepared using the solvent casting technique. The effects of the different concentrations of ethanolic grape seed extract (GSE) on the physicochemical properties, antioxidant properties, and antibacterial properties of CS/κC films were analyzed. The results showed that the addition of GSE inhibited the recrystallization of starch in the composite film. The glass transition temperature of composite film is 121.65 °C. With the addition of GSE, the surface roughness of the composite film increased, and the cross-section displayed a stratification phenomenon. Meanwhile, when GSE was added to the composite film, the tensile strength of the composite film decreased (3.50 ± 0.27 MPa), the elongation at break increased (36.87 ± 2.08%), and the WVP increased (1.58 ± 0.03 g mm/m2·d· kPa). With the increase of the concentration of GSE in the composite film, the a* value and b* value of the composite film increase, the L* value decreases, and the opacity increases. The lipid oxidation test proved that the composite films containing 1% GSE has a significant inhibitory effect on the oxidation of lard (p < 0.05). The above results indicate that the GSE can be used as a food-grade packaging material and has a good application prospect in the food industry.