Relative Crystallinity Research Articles

Influence of egg yolk-curdlan thermal-driven edible coating on the quality and retrogradation behavior of fried rice

To delay the retrogradation and improve the quality of fried rice during freeze-thaw cycles (FTCs), the curdlan (CD) was added to the egg yolk liquid (EYL) to fabricate composite edible coating, leveraging their thermal drive effect. The egg yolk liquid-curdlan (EC) edible coating solutions were investigated using Fourier transform infrared spectroscopy (FTIR) and colorimeter. Results indicated that the blue shift of the egg yolk liquid and the red shift of curdlan confirms the formation of an intermolecular interaction force. Moreover, with the increase of the curdlan concentration, the chroma (C*) of the coating liquid shows a trend of initially increased and then decreased. However, the taste decreased with the increase of the gum concentration in the formula, fortunately, the difference is small at low mass concentrations (≤1%). Additionally, the application of the coating significantly improved the quality of fresh fried rice, especially the moisture content increased by nearly 3.47% and the hardness decreased by nearly 33.19% compared with the pure egg yolk group. During the freeze-thaw cycles, the coating prominently reduced the moisture loss, and delayed the increases of hardness, fluctuation of water migration, and color parameter of fried rice, especially the 1% group. Finally, it also performs well in delayed starch retrogradation after seven freeze-thaw cycles, as reflected by low values for short-range order degree (0.42, 1%), relative crystallinity (8.09%, 1.5%), and retrogradation enthalpy (2.32 J/g, 1%). This further confirms that the egg yolk liquid-curdlan thermal-driven coatings have broad prospects in starch-based food applications.

Preparation of high V-type relative crystallinity dextrin from V-type granular starch via high-temperature acid-ethanol hydrolysis

High V-type relative crystallinity (VRC) dextrin (HVD) was prepared by high-temperature acid-ethanol hydrolysis (HTAEH) of V-type granular starch (VGS). The influence factors including acid concentration, acidolysis temperature and acidolysis duration on HVD production were investigated along with the formation mechanism. HVD with the highest VRC (45.15%) was prepared in 60% (v/v) ethanol at an HCl concentration of 2.0% (w/w), an acidolysis temperature of 95 °C and an acidolysis duration of 30 min. Increasing VRC during the first stage of HTAEH indicated that the V-type crystalline region of VGS was resistant to acid hydrolysis. The molecular weight of VGS was significantly decreased after 10 min∼30 min of HTAEH but remained relatively constant thereafter. The increase in VRC of HVD was due to acid hydrolysis of amylose (AM), and degraded AM with a peak degree of polymerisation of 107 was more easily to complex with ethanol.

Modulating rice digestibility: Mechanisms of ultrasound, oleic acid and moist-heat treatments influence structural, physicochemical and digestive properties

The research compared the combined effect of ultrasound (160 W, 2 min), oleic acid (15%, 11 h), and moist-heat treatment (HMT, 25% moisture content, 110 °C, 2 h) with their individual treatment on rice grains. The results showed that ultrasound treatment created pores and cracks in the rice grains, facilitating an easier penetration for oleic acid to develop amylose-oleic acid complex during HMT. Compared to native raw rice (NR), both single and combined treatments significantly altered the morphology, reduced swelling power and solubility, enhanced hydrophilicity, thus changing the moisture distribution, thermal and pasting characteristics. Notably, the combined treatment of three techniques significantly increased the relative crystallinity, accompanied by the highest digestive resistance, and the content of resistant starch was increased from 20.53% in NR to 31.75%, much higher than the other treatments. These findings provide potential for the manufacturers to rationally and flexibly employ this low digestible rice in health food products.

Effects of nitrogen fertilizer application on the physicochemical properties of foxtail millet (Setaria italica L.) starch

The use of nitrogen fertilizer is a crucial agronomic practice to increase crop output and quality. This study investigated the impact of five nitrogen application levels (0, 60, 135, 210, and 285 kg N/hm2) on the physicochemical properties of foxtail millet (FM) starch. Optimal nitrogen application (210 kg N/hm2) significantly increased L*, a*, and b* values, water and oil absorption capacity, water solubility, and swelling power of starch. The number of small starch granules increased as the nitrogen application rate increased, but the granule morphology and typical A-type pattern did not change among the treatments. Nitrogen application increased the relative crystallinity and ordered structure, resulting in a higher gelatinization enthalpy. Compared to the control group (7.02 J/g), the enthalpy increased by 21.94 %, 66.38 %, 73.50 %, and 103.28 % under the nitrogen application rates, respectively. Moreover, nitrogen application greatly increased the percentage of A and B3 chains while it lowered the apparent amylose content, peak viscosity, and final viscosity. The effects of 210 and 285 kg N/hm2 treatments on the water solubility and swelling power, water and oil absorption, and light transmission of starch were greater compared to the 60 and 135 kg N/hm2 treatments. These results indicate that nitrogen fertilization significantly affects the physicochemical properties of FM starch.

Rheological, textural, and pasting properties of A- and B-type wheat starches in relation to their molecular structures

A- and B-type wheat starches have significant differences in rheological, textural, and pasting properties; however, the structure-property relationship is not fully revealed. Herein, the physicochemical characteristics and molecular structures of A- and B-type starches isolated from three wheat varieties with different apparent amylose contents (2.41%–27.93%) were investigated. A-type starches exhibited higher pasting viscosities, relative crystallinity, onset gelatinization temperatures, and enthalpies, while B-type starches had wide gelatinization temperature ranges. B-type starches had lower resistant starch contents than their A-type counterparts, but B-type starches formed more stable gels and had a lower tendency to retrograde, resulting in lower hardness, storage (G′) and loss (G′′) moduli but higher tan δ values. A-type starches had lower contents of short amylose (100 ≤ X < 1000) and amylopectin chains (DP 6–12) than B-type. These findings elucidated the differences in molecular structures between A- and B-type starches, which can contribute to their effective application.

Effects of Heat Treatment on the Chemical Composition and Microstructure of Cupressus funebris Endl. Wood

The effects of heat treatment on Cupressus funebris Endl. wood were examined under different combinations of temperature, time, and pressure. The chemical composition, crystallinity, and microstructure of heat-treated wood flour and specimens were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Vacuum heat treatment led to changes in the functional groups and microstructure of C. funebris wood, and the relative lignin content decreased with increasing treatment temperature, which was significant at lower negative pressures. Cellulose crystallinity showed a change rule of first increasing and then decreasing throughout the heat treatment range, and the relative crystallinity ranged from 102.46% to 116.39%. The cellulose treated at 120 °C for 5 h at 0.02 MPa had the highest crystallinity of 44.65%. These results indicate that although heat treatment can improve cellulose crystallinity, very high temperatures can lead to decreased crystallinity. The morphology and structure of the cell wall remained stable throughout the heat treatment range; however, at elevated temperatures, slight deformation occurred, along with rupture of the intercellular layer.

Effects of curdlan on the quality of frozen steamed bread: quality changes, water state and starch crystallinity

SummaryThe purpose of the study was to explore the effects of curdlan on the textural and sensory qualities of frozen steamed bread (FSB), as well as water state and starch properties during freezing. The results showed that incorporation of curdlan improved the springiness and resilience, while it reduced the hardness and chewiness of FSB. The quality deterioration of FSB was largely caused by the growth and recrystalisation of ice crystals. However, incorporation of curdlan mitigated this adverse impact by regulating water state. Specifically, it increased water content, inhibited water migration, and significantly decreased freezable water content. Additionally, curdlan also decreased starch relative crystallinity, which hindered its retrogradation and thus maintained the overall quality of FSB. Notably, inclusion of 0.5% curdlan exhibited optimal effectiveness in improving quality as evidenced by the highest sensory score obtained.

Preparation and characterization of carboxymethylated Anemarrhena asphodeloides polysaccharide and its effect on the gelatinization of wheat starch

In this study, a carboxymethylated Anemarrhena asphodeloides polysaccharide (CM-AARP) with an molecular weight (Mw) of 7.8 × 104 Da was obtained. CM-AARP was composed of four monosaccharides including d-mannose, d-glucose, d-galactose, and l-arabinose. Nuclear magnetic resonance (NMR) spectra revealed that the skeleton of CM-AARP was identical to that of AARP. Compared with AARP, CM-AARP had a superior inhibition effect on the gelatinization of wheat starch (WS) under the same condition. The addition of CM-AARP and AARP at 12 % enhanced the gelatinization temperature (60.47 ± 1.30 °C) of WS to 73.88 ± 0.49 °C and 69.75 ± 0.52 °C, respectively. CM-AARP could maintain the crystal structure of WS during gelatinization, the relative crystallinity with the 12 % CM-AARP addition was determined as 29.18 % ± 1.49 %, exceeding that of pure WS at 21.96 % ± 0.66 %. Moreover, CM-AARP influenced the rheological behavior of the gelatinized WS by reducing the viscosity and improving the fluidity. The results suggested that CM-AARP played an essential role in starch gelatinization and was a potential stabilizer in the starch-based food industry.

Improvement of 3D printing age-friendly brown rice food on rough texture, swallowability, and in vitro digestibility using fermentation properties of different probiotics

Probiotics can promote the balance of the intestinal microbial community and enhance the biological activity of food. They are beneficial to the health of elderly people. Therefore, five different probiotics (4% of the total weight) were added to pasted brown rice to study the printability, swallowability, and digestibility of fermented inks (at 40 °C for 10 h). The results showed that probiotics reduced the apparent viscosity and resistance to deformation of brown rice inks. The inks with Lactobacillus bulgaricus (LB), Bifidobacterium longum (BL), and Lactiplantibacillus plantarum (LP) had better printing properties and finer appearances. Probiotics significantly reduced the adhesiveness, gumminess, and hardness of inks but had little effect on cohesiveness. LB, Streptococcus thermophilus (ST), and LP were categorized as having class 4 consistency with easy-to-swallow characteristics. The growth and multiplication of probiotics detached the internal structure of brown rice inks and reduced the relative crystallinity. They also modulated the nutrient content and flavor components by producing short-chain fatty acids, and improved the digestion of starch.

Changes in the starch quality of adlay seed varieties (Coix lacryma-jobi L.) from different regions in China after high-temperature storage

The effects of high-temperature storage at 37 °C on the crystallinity, pasting, rheological, and thermal properties of adlay seed starches from three famous Chinese varieties were studied. The results showed that high-temperature storage altered the natural structure of adlay seed starch, resulting in increased peak viscosity for all starch pastes after one month of storage at 37 °C. Jinsha adlay seed starch (JSC), which had the highest amylose content (11.21 %), showed increased D50, relative crystallinity and OD values, demonstrating strong regrowth ability and hydrophobicity, with starch gels having greater hardness and gumminess after storage. In contrast, Pucheng adlay seed starch (PSC) and waxy Ninghua adlay seed starch (WSC), with similar amylose proportions, showed distinct starch gel properties. PSC (with an amylose content of 3.35 %) exhibited better starch gel properties, whereas WSC (amylose content of 5.74 %) demonstrated improved gumminess and chewiness after storage and exhibited stronger anti-starch regrowth capabilities. This study provides valuable insights into the selection of future starches based on their specific processing requirements.

Evaluation of quality characteristics of ultrasound–treated browntop millet grains

Modification of grains using green technologies receiving more attention in today's world for better utilization. Browntop millet was treated at a frequency of 20 kHz using probe ultrasound at 100 & 200 W for 5–35 min of 5 min intervals between the treatment at the ratio of 1:5 (w/v). The impact of treatment on grains was evaluated utilizing several parameters, such as relative crystallinity (RC) of the treated samples, which decreased from 59.78 % to 34.41 % at 100 W and 22.84 % at 200 W. Change in the surface morphology of the samples was observed by SEM which had a positive impact on water absorption as it increased from 164% to 179.2%; thus, the cooking time in treated samples is reduced from 18.8 to 7.9 min. Thermal and pasting properties showed a decrease in temperature and increase in viscosity of the treated samples from 74 to 70.7 °C, and 4.23 Pa.s to 11.50 Pa.s this shows that grains with lesser gelatinized temperature tends to cook fast and has the softer texture, thus sonicated samples have better eating quality. Among all the trials 200 W 20 min were the optimal conditions for the browntop millet with lesser cooking time, relative crystallinity.

Effects of different pretreatment methods on the degree of substitution, structure, and physicochemical properties of synthesized malic acid sweet potato starch ester.

The preparation of malic acid starch ester (MSE) is mostly carried out using a high temperature method, but there are problems such as high energy consumption, long preparation time, and uneven heating. Microwave technology can be used to overcome these limitations. The semi-crystalline structure of starch granules hinders the modifier's access to the matrix, thus limiting the esterification reaction. Physical techniques can act on the interior of the starch to create a number of active sites, thereby facilitating the reaction of the starch with esterification reagents. Therefore, this study investigated the effect of starch pretreatment by microwave, heat-moisture, and ultrasonic techniques on the degree of substitution (DS), structure, and physicochemical properties of MSE synthesized by the microwave method. The DS of MSE was increased after pretreatments. The modified starch obtained by different pretreatment methods did not show new characteristic peaks, while the MSE synthesized showed new absorption peaks near 1735 cm-1. The granular structure and morphology of the modified starch obtained by microwave and heat-moisture pretreatment were gelatinized and aggregated, while some of the starch particles of the modified starch obtained by ultrasonic pretreatment appeared pore-sized. The relative crystallinity and gelatinization enthalpy of the MSE were reduced, but the crystallization pattern remained as A-type. Overall, the results suggest that various pretreatment methods can enhance the DS of MSE by disrupting the structure of starch. The findings of this study provide theoretical support for improving the DS of esterified starch. © 2024 Society of Chemical Industry.

Crystallinity and rheological behavior of polyetheretherketone during nonisothermal conditions

AbstractSolidification models are key during simulation of several industrial processes involving thermoplastics. For simplicity, crystallinity is often not considered within these models, despite it being responsible for the phase transition. Several advanced methods, which consider crystallinity as the onset of solidification have been proposed in literature however, these have primarily been applied to classical homopolymers such as polypropylene (PP). The focus of this study is to develop a model that can capture the rheological response observed during the transition from liquid‐like to solid‐like behavior in injection molding grade polyetheretherketone (PEEK) due to crystallinity. Isothermal rheological experiments are performed alongside dynamic scanning calorimetry (DSC) characterization to correlate relative crystallinity to the apparent increase in viscosity. The model is extended to nonisothermal processes through the incorporation of the Nakamura model. Nonisothermal crystallization rheology experiments are performed and compared with a simulation of the oscillating rheometer process for validation. The modeled viscosity response and crystallization half‐time reproduced the experimental data with sufficient accuracy at low cooling rates, with an error of less than 5% up to cooling rates of 20°C min−1. This shows that the method is an accurate means of obtaining the rheological response during crystallization in a numerical simulation.

Rapid production of hydroxysodalite from a clay-based waste through microwave-assisted technique for treatment of wastewater contaminated with zinc cation

In the current work, the cabbage-like hydroxysodalite powder was produced from a clay-based waste deposited in the landfill of raw vegetable oil refinery through the microwave-assisted technique to treat the wastewater discharged from a zinc extraction industry. The selected waste was a Ca-bentonite, mainly containing montmorillonite, illite, and kaolinite which contaminated with the vegetable oil components. The effects of microwave irradiation power, and time on crystalline structure of products as well as uptake of heavy metal ions like zinc, cadmium, nickel, and aluminum were studied in details. The experimental results showed that the partial recrystallization of hydroxysodalite under the irradiation power of 200 W within 10–15 min contributes to the enhancement of adsorption efficiency. The maximal uptake of heavy metal ions was obtained in the relative crystallinity range of 22.5–43.0%. The prepared adsorbent possessed the higher efficiency, 94.0%, for the immobilization of Zn2+ from the concentrated wastewater, 413 mg L−1. The competitive adsorption of Cd2+, Ni2+, and Al3+ ions over the hydroxysodalite was extremely dependent on the ion concentration. Furthermore, the adsorption kinetics of Zn2+ over the hydroxysodalite particles follows the pseudo-second-order (PSO) model, indicating the chemical nature of treatment process. The equilibrium data were fitted by the Langmuir isotherm, confirming the homogenous, and monolayer adsorption. The presented route for the production of hydroxysodalite is facile, and rapid in comparison to hydrothermal method.

Effect of chickpea thermal treatments on the starch digestibility of the fortified biscuits

Flour of roasted and heat-moisture treated chickpeas was used as a partial replacement of wheat flour, facilitating the development of biscuits with delayed digestion properties. The multiscale structural properties of starch and microstructural changes in chickpea flour and fortified biscuits were analyzed. Chickpea thermal treatment reduced the starch digestibility of fortified biscuits by 5.43%–7.33%, enhanced the resistant starch content of chickpea flour by 7.86%–12.28%. For thermal-treated chickpea fortified biscuits, the degree of relative crystallinity, short-range order, and double helix of starch was enhanced, the pasting viscosity was reduced, and the heat-moisture treatment showed a significant effect. Scanning electron microscope showed that fortified biscuits had a continuous and denser microstructure, reducing the accessibility of enzymes to hydrolyze starch molecules. The glycemic index values of fortified biscuits were reduced to below 66 in mice, as seen by their postprandial blood glucose response. Altogether, these results provide guidance for the development of delayed digestion meal replacement biscuits.

Structural properties and antioxidant capacity of different aminated starch-phenolic acid conjugates

Different aminated starch (AS) [EEAS (introducing ethylenediamine into starch using cross-linking-etherification-amination method (CEA)), EPAS (introducing o-phenylenediamine using CEA), OEAS (introducing ethylenediamine using cross-linking-oxidation-amination method (COA)), and OPAS (introducing o-phenylenediamine using COA)] were synthesized. The AS-phenolic acids [gallic acid (GA), syringic acid (SA), and vanillic acid (VA)] conjugates were prepared by laccase-catalyzed reaction. The grafting efficiency of EEAS on GA, SA, and VA was 36.59%, 69.71%, and 68.85%, respectively. SA reduced the maximum depolymerization rate of EEAS. The relative crystallinity of EEAS and EPAS grafted phenolic acid increased, and their particles showed severe breakage in appearance. OEAS-phenolic acid conjugates lost its granular structure and behaved as flakes and lumps, while the surface of OPAS-phenolic acid conjugates remained smooth after grafting phenolic acid. GA increased the DPPH· scavenging efficiency of EEAS from 16.12% to 79.92%. The increased antioxidant capacity of the conjugates suggested that AS-phenolic acids conjugates have high potential for applications.

Freezing rate's impact on starch retrogradation, ice recrystallization, and quality of water-added and water-free quick-frozen rice noodles

The study evaluated the effect of freezing rate on the quality of water-added quick-frozen rice noodles and water-free quick-frozen rice noodles. Results indicated that the retrogradation enthalpy, relative crystallinity, freezable water content, and cooking loss of water-added quick-frozen rice noodles were higher than those of water-free quick-frozen rice noodles with increasing storage time. Furthermore, ice recrystallization accelerated the deterioration of the quality of the rice noodles, resulting in the enlargement of the pores within the rice noodles and the formation of many pores on the surface. This phenomenon was particularly evident in the rice noodles of Y-40 °C (freezing with water at −40 °C) and Y-60 °C (freezing with water at −60 °C). After 28 days of frozen storage, the hardness increased by 83.83 % for rice noodles of Y-20 °C (freezing with water at −20 °C), while the hardness decreased by 51.68 % and 45.80 %, respectively, for rice noodles of Y-40 °C and Y-60 °C. Consequently, the impact of the freezing rate on the quality of water-added quick-frozen rice noodles is more pronounced than that of water-free quick-frozen rice noodles. Moreover, a higher freezing rate can delay the deterioration of the quality of frozen rice noodles by postponing starch retrogradation and inhibiting ice recrystallization.

Structural features of rice starch-protein system: Influence of retrogradation time and quick-freezing temperature

This work investigated the effect of retrogradation time (0 h, 2 h, 4 h, 6 h, 8 h) and freezing temperature (−20 °C, −32 °C, −80 °C) on the muti-scale structures of the rice starch-protein system of quick-frozen wet rice noodles. The Relative crystallinity and porosity of the rice starch-protein system increased with increasing retrogradation time. However, while longer retrogradation does lead to an improvement in relative crystallinity, it also results in significant damage to the microstructure. When the retrogradation time was 6 h, the microstructure of the rice starch-protein system was less damaged and the quality was better. The mass fractal dimension and relative crystallinity of the rice starch-protein system exhibited an increase as the freezing temperature was decreased from −20 to −80 °C. Additionally, the retrogradation degree of starch decreased, the size of ice crystals decreased, and the disruption of microforms was reduced. The muti-scale structures of the rice starch-protein systems were similar when quick-frozen at temperatures of −32 and −80 °C. Therefore, the optimal treatment method for practical production is to quick-freeze at −32 °C and age for 6 h to obtain high-quality quick-frozen wet rice noodles.

Novel ionic polymers encompassing di-cationic pyridinium hydrazones and aromatic ester as potent antimicrobial agents against resistant bacteria

In this work, readily achievable synthetic pathways including quaternization, metathesis and copolymerization reactions were utilized for the construction of a new di-pyridinium monomers and their respected ionic polymers scaffold with ester fragments. All synthesized material were well characterized by spectroscopic experiments. The surface morphology and thermal study of the produced polyesters were carried out using SEM, PXRD, and TGA analysis. The impact of the counter anions on the crystallinity and thermal analysis of the polymer network was confirmed by thermal analysis and surface investigation. The related polyesters' crystallinity was decreased, and their thermal stability was increased by the TFSI anion. Various significant consequences regarding the development of innovative antibacterial agents along with specific therapies. Subsequently, we evaluated the antimicrobial, antibiotic resistant strains, and anti-prophage properties of these novel class of ionic and poly-ionic materials. Throughout antibacterial studies, the M-Br monomer excelled all synthesized materials, although PPy-TFSI and its monomer outperformed antibiotic-resistant organisms. Both M-PF6 and PPy-PF6 decreased S. aureus bacteriophage proliferation. Understanding the bacterial species or strains that are vulnerable to polyesters encourages subsequent studies in this field to focus on creating targeted therapies for illnesses caused by these pathogens.

Structures, gelatinization properties and enzyme hydrolyses of starches from transparent and floury grains of rices subjected to field natural extreme high temperature

Three rice varieties underwent the field natural extreme high temperature (EHT) with daily average temperature over 30 °C from 21 to 89 days after sowing, and had transparent, chalky and floury grains. The structures, gelatinization properties and enzyme hydrolyses of starches from transparent and floury grains were investigated. Compared with control transparent grains, floury grains subjected to EHT markedly decreased the contents of amylose molecules, amylopectin A chains and amylopectin B1 chains and increased the contents of amylopectin B2 and B3+ chains and the average branch-chain length of amylopectin. Both transparent and floury grains had A-type starches, but floury grain starches exhibited higher relative crystallinity, gelatinization temperature, retrogradation and pasting viscosities than transparent grain starches. Floury grain starches had lower hydrolysis rates than transparent grain starches. Native starches were more resistant to digestion but gelatinized and retrograded starches were more prone to digestion in floury grains than in transparent grains.