Thermal Denaturation Research Articles

Investigation of the ability of 3-((4-chloro-6-methyl pyrimidin-2-yl)amino) isobenzofuran-1(3H)-one to bind to double-stranded deoxyribonucleic acid.

Phthalides represent a notable category of secondary metabolites that are prevalent in various plant species, certain fungi, and liverworts. The significant pharmacological properties of these compounds have led to the synthesis of a novel phthalide derivative. The current study focuses on investigating the binding interactions of a newly synthesized 3-substituted phthalide derivative, specifically 3-((4-chloro-6-methyl pyrimidine-2-yl)amino) isobenzofuran-1(3H)-one (Z11), with double-stranded deoxyribonucleic acid (dsDNA). Research in the pharmaceutical and biological fields aimed at developing more potent DNA-binding agents must take into account the mechanisms by which these newly synthesized compounds interact with DNA. This investigation seeks to explore the binding dynamics between dsDNA and our compound through a variety of analytical techniques, such as electrochemistry, UV spectroscopy, fluorescence spectroscopy, and thermal denaturation. The binding constant (Kb) of Z11 with DNA was determined using both spectroscopic and voltammetric approaches. The research revealed that Z11 employs a groove binding mechanism to associate with dsDNA. To further explore the interactions between Z11 and dsDNA, the study utilized density functional theory (DFT) calculations, molecular docking, and molecular dynamics simulations. These analyses aimed to ascertain the potential for a stable complex formation between Z11 and dsDNA. The results indicate that Z11 is situated within the minor groove of the dsDNA, demonstrating the ability to establish a stable complex. Furthermore, the findings imply that both π-alkyl interactions and hydrogen bonding play significant roles in the stabilization of this complex.

Engineering a Mesoporous Silicon Nanoparticle Cage to Enhance Performance of a Phosphotriesterase Enzyme for Degradation of VX Nerve Agent.

The organophosphate (OP)-hydrolyzing enzyme phosphotriesterase (PTE, variant L7ep-3a) immobilized within a partially oxidized mesoporous silicon nanoparticle cage is synthesized and the catalytic performance of the enzyme@nanoparticle construct for hydrolysis of a simulant, dimethyl p-nitrophenyl phosphate (DMNP), and the live nerve agent VX is benchmarked against the free enzyme. In a neutral aqueous buffer, the optimized construct shows a ≈2-fold increase in the rate of DMNP turnover relative to the free enzyme. Enzyme@nanoparticles with more hydrophobic surface chemistry in the interior of the pores show lower catalytic activity, suggesting the importance of hydration of the pore interior on performance. The enzyme@nanoparticle construct is readily separated from the neutralized agent; the nanoparticle is found to retain DMNP hydrolysis activity through seven decontamination/recovery cycles. The nanoparticle cage stabilizes the enzyme against thermal denaturing and enzymatic (trypsin) degradation conditions relative to free enzyme. When incorporated into a topical gel formulation, the PTE-loaded nanoparticles show high activity toward the nerve agent VX in an ex vivo rabbit skin model. In vitro acetylcholinesterase (AChE) assays in human blood show that the enzyme@nanoparticle construct decontaminates VX, preserving the biological function of AChE when exposed to an otherwise incapacitating dose.

Metabolomic analysis of HUVEC after Thermal denaturation UHPLC-MS/MS-based metabolomics.

Preserving denatured dermis has been shown to promote wound healing and improve skin appearance and function. Angiogenesis is crucial for the healing of burn wounds. However, the metabolic mechanisms underlying angiogenesis during burn recovery remain unclear. In this study, ultra-high performance liquid chromatography-mass spectrometry analysis revealed six distinct metabolites in a heat-denatured cell model. A bioinformatics approach was used to predict the differentially expressed metabolites, and four metabolic pathways closely related to trauma repair were identified. These pathways might play a significant role in the regression of thermally injured endothelial cells. We also found that increasing D-mannose level promoted the angiogenic activity of human umbilical vein endothelial cells in the heat-denatured cell model, enhancing cell proliferation, migration, and tube formation. In summary, these findings revealed changes in metabolites and metabolic pathways in thermally injured endothelial cells, and demonstrated that D-mannose could promote angiogenesis during the recovery of thermally injured endothelial cells.

Preparation of mayonnaise with excellent thermal and storage stability from egg yolk-amino acid complex: Rheology, interfacial property, microstructure and lutein delivery.

In this paper, egg yolk-amino acid (betaine or proline) complex was prepared at different pasteurization temperatures (68, 72 and 76 °C). Then complexes were applied to stabilized mayonnaise emulsion system. The results demonstrated that liquid egg yolk (LEY) protein structure gradually aggregated, molecular flexibility increased by 5 %, interfacial tension and intermolecular force enhanced remarkably with growth of pasteurization temperature. Compared with LEY, egg yolk-amino acid complex exhibited a more flexible structure with lower interfacial tension and superior molecular wettability. Complexes stabilized mayonnaise emulsion displayed excellent rheological property, homogeneous droplet distribution, smaller average particle size and higher (about 10 °C) thermal denaturation temperature (Td). In terms of thermal stability, oil binding capacity (OBC) of heated betaine mayonnaise (HBM) and heated proline mayonnaise (HPM) was approximately 20 % higher than that of heated control mayonnaise (HCM). Notably, the group of HBM thermal stability was generally excellent. During storage, mayonnaise might be an intermediate unstable state before emulsion breakage. In vitro digestion results illustrated that bioaccessibility of lutein delivered by BM-72 and PM-72 was 48.9 % and 37.0 % higher than CM-72, respectively. The results will provide reference for preparation of mayonnaise by egg yolk-amino acid complex as a carrier to deliver fat-soluble substances to improve bioaccessibility.

Determinants for Sugar-Induced modulation of thermodynamic stability of lysozyme

The current study focuses on the experimental evidence to describe the molecular mechanism by which the sugars modulate the thermodynamic stability of hen egg-white lysozyme (Lyz) at pH 2.3. Analysis of thermal and chemical denaturation curves of Lyz under variable concentrations of sugar (trehalose, sucrose, maltose, glucose, ribose, glycerol) at pH 2.3 depicted important results: (i) sugar increases the thermodynamic stability of Lyz, and it typically tracks the order as: trehalose > sucrose > maltose > glucose > ribose > glycerol, and (ii) sugar increases the thermodynamic stability of Lyz via preferential exclusion of sugar at the protein surface, but the repulsive enthalpic interactions of sugar with protein also add to the sugar-mediated increase in thermodynamic stability of the protein. Analysis of the sugar effect on denaturant concentration dependent denaturation free energy of Lyz at pH 2.3 revealed that the sugar counteracts the denaturant (urea, guanidinium chloride (GdnCl)) efficacy to decrease the thermodynamic stability of Lyz. Furthermore, the counteraction efficiency of sugar on denaturant impact to decrease thermodynamic stability of Lyz typically tracks the order as: trehalose > sucrose > maltose > glucose > ribose > glycerol.

Sustained germination-promoting effect of cold atmospheric plasma on spinach seeds.

Cold atmospheric plasma (CAP) irradiation exhibits sterilizing effect without causing thermal denaturation or leaving behind residual toxicants. CAP also has potential applications in various fields, including agriculture, leading to research efforts in recent years. This study investigated the effects of CAP on the seed germination rate of spinach (Spinacia oleracea), which typically has a low seed germination rate. Our results confirmed that irradiation with N2-CAP and Air-CAP significantly enhanced the germination rate of spinach seeds. Notably, we discovered that CAP irradiation promoted germination even in spinach seeds coated with a fungicide (thiuram) and a disinfectant (Captan), which are commonly used. Additionally, we examined whether the interval between CAP irradiation and the subsequent germination-induction treatment influenced the germination efficiency. We found that the germination-promoting effect of CAP on spinach seeds persisted for at least 30 days, demonstrating the high utility and practicality of CAP in the agricultural sector.

Spectroscopic Investigation of the Quadruplex DNA‐Binding Properties of 9‐Aryl‐Substituted Isoquinolinium Derivatives

AbstractThe spectroscopic investigation of the binding properties of berberine‐type 9‐aryl‐substituted isoquinolinium derivatives with G‐quadruplex DNA (G4‐DNA) are presented. Photometric titrations show that these ligands bind with high affinity to the telomeric G4‐DNA form 22AG (K=1.0–44×105 M−2). Furthermore, fluorimetric analysis of thermal DNA denaturation (FRET melting) reveals a significant thermal stabilization of G4‐DNA 22AG upon association with the methoxy‐substituted derivatives. As an analytically useful property, the derivatives with a phenyl substituent or with additional electron‐donating groups show a very weak fluorescence intensity, which increased significantly upon G4‐DNA complexation (fluorescence light‐up effect). Additional time‐resolved fluorescence spectroscopy indicated increased fluorescence lifetimes of the DNA‐bound 9‐(4‐methoxyphenyl)‐substituted derivative, when interacting with the quadruplex‐forming strand 22AG. Notably, the changes of the steady‐state and time‐resolved emission properties of the ligand are more pronounced with G4‐DNA than with duplex DNA so that the combination of these complementary methods may be used for the selective G4‐DNA detection.

C4 grasses employ distinct strategies to acclimate rubisco activase to heat stress.

Rising temperatures due to the current climate crisis will soon have devastating impacts on crop performance and resilience. In particular, CO2 assimilation is dramatically limited at high temperatures. CO2 assimilation is accomplished by rubisco, which is inhibited by the binding of inhibitory sugar phosphates to its active site. Plants therefore utilize the essential chaperone rubisco activase (RCA) to remove these inhibitors and enable continued CO2 fixation. However, RCA does not function at moderately high temperatures (42°C), resulting in impaired rubisco activity and reduced CO2 assimilation. We set out to understand temperature-dependent RCA regulation in four different C4 plants, with a focus on the crop plants maize (two cultivars) and sorghum, as well as the model grass Setaria viridis (setaria) using gas exchange measurements, which confirm that CO2 assimilation is limited by carboxylation in these organisms at high temperatures (42°C). All three species express distinct complements of RCA isoforms and each species alters the isoform and proteoform abundances in response to heat; however, the changes are species-specific. We also examine whether the heat-mediated inactivation of RCA is due to biochemical regulation rather than simple thermal denaturation. We reveal that biochemical regulation affects RCA function differently in different C4 species, and differences are apparent even between different cultivars of the same species. Our results suggest that each grass evolved different strategies to maintain RCA function during stress and we conclude that a successful engineering approach aimed at improving carbon capture in C4 grasses will need to accommodate these individual regulatory mechanisms.

Fluorescent Protein PEGylation for Stable Photon Manipulation in Deep‐Red Light‐Emitting Devices

AbstractPEGylation is a classic strategy to reduce denaturation and immunogenicity in therapeutic proteins, bioimaging, and drug delivery. However, this concept has not been applied to incorporate biogenic materials as functional components in optoelectronics. Herein, PEGylation is rationalized as an effective tool to stabilize fluorescent proteins in solid‐state photon manipulation down‐converters integrated into bio‐hybrid light‐emitting diodes. In short, the archetypal red‐emitting protein mCherry is nonspecifically PEGylated with methoxypolyethylene glycols (mPEG) chains of different lengths (mPEG‐350/‐750/‐2000). These derivatives hold the same photoluminescence figures‐of‐merit of mCherry, but an improved resistance against organic solvents, pH, temperature, and polymers (in solution/dry‐coatings) upon increasing the mPEG length. Indeed, the best‐performing mCherry‐mPEG‐2000 adduct leads to deep‐red devices with threefold enhanced color stability (>300 h) under harsh operation conditions (150 mW cm−2) over the prior art. Different device architectures along with spectroscopic, thermocycling, and electrochemical impedance spectroscopy studies of the prepared coatings aid in rationalizing that PEGylation successfully reduces i) nonreversible thermal denaturation, ii) aggregation in solid‐state, and iii) photo‐induced oxidation and H+‐transfer deactivation of the chromophore, since oxygen diffusivity and H+‐reorganization across the protein skeleton are slowed down by strong H+‐bonding/hydrophobic mCherry‐mPEG interactions. Hence, this simple supramolecular modification is of utmost relevance for future advances in protein‐based optoelectronics.

Gelation and dough‐forming properties of canary seed protein concentrate in comparison with commercial soy protein concentrate and vital wheat gluten

AbstractBackground and ObjectivesIn this study, a lab‐scale process was developed to aqueously de‐oil canary seed (yellow and brown‐seeded) flour and derive a protein concentrate. The protein concentrates prepared were evaluated for their gelation and bread dough‐forming properties.FindingsThe aqueous process successfully reduced the oil content in both yellow‐seed and brown‐seed roller‐milled flour. The protein concentrate prepared from yellow‐seed flour and brown‐seed flour had 74.9% and 68.6% purity (dry weight basis), respectively. Proteins showed high resistance to thermal denaturation (peak denaturation at 107°C). It was found that the least gelation concentration of both protein concentrates was 16% (w/w). There were no significant differences in viscoelastic properties and water holding capacity between the protein gels of these two canary seed types and the addition of salt did not noticeably improve these properties. Compared to canary seed, commercial soy protein showed better gelation properties. Both yellow and brown canary seed protein showed a good potential for improving bread dough strength when incorporated into a low‐gluten‐strength wheat flour and was comparable to commercial vital wheat gluten at 1%–3% (w/w) inclusion levels.ConclusionsThe new canary seed protein ingredients prepared by the solvent‐free aqueous‐based process hold good potential for application in food formulation based on their gelation and bread dough‐forming properties.Significance and NoveltyThe gelation and dough‐forming properties of canary seed were not previously studied; therefore, this study provides an insight into those properties for potential food applications for canary seed proteins, which is important for canary seed market diversification as a novel protein source.

Thermal Denaturation of Fresh Frozen Tissue Enhances Mass Spectrometry Detection of Peptides.

Thermal denaturation (TD), known as antigen retrieval, heats tissue samples in a buffered solution to expose protein epitopes. Thermal denaturation of formalin-fixed paraffin-embedded samples enhances on-tissue tryptic digestion, increasing peptide detection using matrix-assisted laser desorption ionization imaging mass spectrometry (MALDI IMS). We investigated the tissue-dependent effects of TD on peptide MALDI IMS and liquid chromatography-tandem mass spectrometry signal in unfixed, frozen human colon, ovary, and pancreas tissue. In a triplicate experiment using time-of-flight, orbitrap, and Fourier-transform ion cyclotron resonance mass spectrometry platforms, we found that TD had a tissue-dependent effect on peptide signal, resulting in a (22.5%) improvement in peptide detection from the colon, a (73.3%) improvement in ovary tissue, and a (96.6%) improvement in pancreas tissue. Biochemical analysis of identified peptides shows that TD facilitates identification of hydrophobic peptides.

Development of Tunable Mechanism-Based Carbasugar Ligands that Stabilize Glycoside Hydrolases through the Formation of Transient Covalent Intermediates.

Mutations in many members of the set of human lysosomal glycoside hydrolases cause a wide range of lysosomal storage diseases. As a result, much effort has been directed toward identifying pharmacological chaperones of these lysosomal enzymes. The majority of the candidate chaperones are active site-directed competitive iminosugar inhibitors but these have met with limited success. As a first step toward an alternative class of pharmacological chaperones we explored the potential of small molecule mechanism-based reversible covalent inhibitors to form transient enzyme-inhibitor adducts. By serial synthesis and kinetic analysis of candidate molecules, we show that rational tuning of the chemical reactivity of glucose-configured carbasugars delivers cyclohexenyl-based allylic carbasugar that react with the lysosomal enzyme β-glucocerebrosidase (GCase) to form covalent enzyme-adducts with different half-lives. X-ray structural analysis of these compounds bound noncovalently to GCase, along with the structures of the covalent adducts of compounds that reacted with the catalytic nucleophile of GCase, reveal unexpected reactivities of these compounds. Using differential scanning fluorimetry, we show that formation of a transient covalent intermediate stabilizes the folded enzyme against thermal denaturation. In addition, these covalent adducts break down to liberate the active enzyme and a product that is no longer inhibitory. We further show that the one compound, which reacts through an unprecedented SN1'-like mechanism, exhibits exceptional reactivity-illustrated by this compound also covalently labeling an α-glucosidase. We anticipate that such carbasugar-based single turnover covalent ligands may serve as pharmacological chaperones for lysosomal glycoside hydrolases and other disease-associated retaining glycosidases. The unusual reactivity of these molecules should also open the door to creation of new chemical biology probes to explore the biology of this important superfamily of glycoside hydrolases.

Effect on heat treatment on the physical stability, interfacial tension and in vitro digestion of whey protein-stabilized ω-6/ω-3 fatty acid balanced pumpkin seed oil complex condensate

Despite the fact that whey proteins (WP) have shown diverse functional and nutritional properties, they exhibit poor stability when exposed to temperatures above the thermal denaturation point. Therefore, in this study, a complex coacervation layer of formed by WP treated at different heating temperatures (55, 65, 75 and 85 °C) and gum arabic (GA) was used as a wall material to microencapsulate ω-6/ω-3 fatty acid balanced pumpkin seed oil (MPO) with a view to exploring the effect of heat treatment temperatures on the nature of microencapsulation stabilized by WP-GA complexes. At pH 3.6, WP and GA formed a strong electrostatic complex. When the heat treatment temperature reached 65 °C, the WP-GA complexes exhibited more excellent particle size, absolute potential, emulsification properties and structural changes, which made them more suitable as hydrophilic emulsifiers to stabilize oil/water (O/W) systems. Further research into the physical properties and interfacial characteristics of O/W emulsions formed by the WP-GA complex was conducted. When subjected to a heat treatment temperature of 65 °C, the O/W emulsions achieved a higher interfacial protein content (3.17 ± 0.08 mg/m2), along with a lower interfacial tension (15.52 mN/m). Additionally, the encapsulated MPO demonstrates superior oxidative stability compared to its unencapsulated counterpart. In-vitro simulated digestion experiments revealed that only small fraction (17.70 ± 1.13%) of the encapsulated oil was released in simulated gastric fluid, while the majority (76.70 ± 1.47%) was released in simulated intestinal fluid, which suggested that the WP-GA composite coacervates was a promising encapsulation shell material, capable of maintaining integrity in the gastric phase and effectively delivering the encapsulant to the intestinal phase.

Comparative study of Maillard reaction and blending between soybean protein isolate and soluble soybean polysaccharide: Physicochemical, structure and functional properties

Soybean protein isolate-soluble soybean polysaccharide (SPI-SSPS) complexes and mixtures with varying SPI/SSPS concentration ratios (1: 1, 2:1, 4:1, 8:1) were prepared by Maillard reaction and blending, respectively, and their physicochemical, structure, and functional properties were compared studied. The physical stability of SPI-SSPS complex, which consisted of CN and CS bonds, was better than that of the SPI/SSPS mixture with electrostatic interactions and hydrogen bonds, and both were superior SPI alone. The complex with SPI/SSPS concentration ratio of 8:1 had the highest grafting degree (33.25 %) and a more ordered structure, making its solubility and emulsifying property lower than the SPI/SSPS mixture; however, the physical and thermal stability of the SPI-SSPS complex was higher than that of the SPI and SPI/SSPS mixture. In particular, the SPI-SSPS complex with a high grafting degree showed a higher thermal denaturation temperature (194.06 °C). This study aimed to provide effective modification methods to utilize soybean processing by-products by modifying soybean protein isolate with soluble soybean polysaccharide.

Nanoscale Surface Metal-Coating Method without Pretreatment for High-Magnification Biological Observation and Applications.

Biospecimen imaging is essential across various fields. In particular, a considerable amount of research has focused on developing pretreatment techniques, ranging from freeze-drying to the use of highly conductive polymers, and on advancements in instrumentation, such as cryogenic electron microscopy. These specialized techniques and equipment have facilitated nanoscale and microscale bioimaging. However, user access to these environments remains limited. This study introduced a novel technique to achieve high conductivity in bioimaging by employing a magnetically controlled sputtering cathode to facilitate low-temperature deposition and low-electron bombardment. This approach allows for the convenient high-magnification observation of highly structured three-dimensional specimens, such as pill bugs and butterfly wings, and fragile specimens, such as single-cell protozoan parasites, using metal deposition only. Furthermore, it is easily accessible in the field of bioimaging because it does not require any pretreatment and enables surface analysis of biospecimens with an electron microscope using only a single pretreatment process. Protozoa, which are microorganisms, were successfully observed at high magnification without structural changes due to thermal denaturation. Furthermore, metallic film deposition and electrochemical signal measurements using these metallic films were achieved in pill bugs.

Effect of solution environment on the binding properties of ruthenium(II) complexes [Ru(bim)2(7-CH3-dppz)]2+ and [Ru(bim)2(dppx)]2+ with double-stranded RNA poly(A)·poly(U)

Two new ruthenium(Ⅱ) complexes containing the same ancillary ligands and different intercalating ligands, [Ru(bim)2(7-CH3-dppz)]2+ (Ru1, bim = 2,2′-biimidazole, 7-CH3-dppz = 7-methyl-dipyrido-[3,2-a,2′,3′-c]-phenazine) and [Ru(bim)2(dppx)]2+ (Ru2, dppx = 7,8-dimethyldipyridophenazine), have been synthesized and characterized in this work, and the interactions of Ru1 and Ru2 with double-stranded RNA poly(A)·poly(U) have been comparatively studied under both dilute and molecular crowding conditions. Analysis of spectral titrations and viscosity experiments as well as thermal denaturation experiments suggests that although complexes Ru1 and Ru2 in both dilute and molecular crowding solutions bind to poly(A)·poly(U) via intercalation, while the binding and stabilizing effects of the two complexes toward poly(A)·poly(U) under molecular crowding conditions significantly decreases in comparision with those in dilute solutions, suggesting that molecular crowding has a significant weakening effect on the interaction of the two complexes with poly(A)-poly(U). The results obtained will contribute to the understanding of the effects of molecular crowding conditions on the binding and stabilization of double-stranded RNA by metal complexes, in particular Ru(II) complexes.

Properties of Skin Collagen from Southern Catfish (Silurus meridionalis) Fed with Raw and Cooked Food.

The southern catfish (Silurus meridionalis) is an economically important carnivorous freshwater fish in China. In this study, we compared the properties of skin collagen from southern catfish fed with raw food (RF) and cooked food (CF). The skin collagen yield in the RF group (8.66 ± 0.11%) was significantly higher than that of the CF group (8.00 ± 0.27%). SDS-PAGE, circular dichroism spectroscopy, and FTIR analyses revealed that the collagen extracted from southern catfish skin in both groups was type I collagen, with a unique triple helix structure and high purity. The thermal denaturation temperature of collagen in the RF group (35.20 ± 0.11 °C) was significantly higher than that of the CF group (34.51 ± 0.25 °C). The DPPH free radical scavenging rates were 68.30 ± 2.41% in the RF collagen and 61.78 ± 3.91% in the CF collagen, which was higher than that found in most fish collagen. Both the RF and CF groups had high ability to form fibrils in vitro. Under the same conditions, the CF group exhibited faster fibril formation and a thicker fibril diameter (p < 0.05). In addition, the RF group exhibited significantly higher expression of col1a1 compared to the CF group. These results indicated that feeding southern catfish raw food contributed to collagen production, and the collagen from these fish may have potential in biomaterial applications.

Interactions of human serum albumin with phosphate and Tris buffers: impact on paclitaxel binding and nanoparticles self-assembly

Aim To investigate the conformational changes in human serum albumin (HSA) caused by chemical (CD) and thermal denaturation (TD) at pH 7.4 and 9.9, crucial for designing controlled drug delivery systems with paclitaxel (PTX). Methods Experimental and computational methods, including differential scanning calorimetry (DSC), UV-Vis and intrinsic fluorescence spectroscopy, mean diameter, polydispersity index (PDI), ζ-potential, encapsulation efficiency (EE), in vitro release and protein docking studies were conducted to study the HSA denaturation and nanoparticles (NPs) preparation. Results TD at pH 7.4 produced smaller NPs (287.1 ± 12.9 nm) than CD at pH 7.4 with NPs (584.2 ± 47.7 nm). TD at pH 9.9 exhibited high EE (97.3 ± 0.2%w/w) with rapid PTX release (50% within 1h), whereas at pH 7.4 (96.4 ± 2.1%w/w), release only 40%. ζ-potentials were around −30 mV. Conclusion Buffer type and pH significantly influence NP properties. TD in PBS at pH 7.4, provided optimal conditions for a stable and efficient drug delivery system.

Film-forming modifications and mechanistic studies of soybean protein isolate by glycerol plasticization and thermal denaturation: A molecular interaction perspective

Plasticizer and thermal denaturation are indeed important factors for soybean protein film formation. The objective of the study was to investigate the effects of glycerol and thermal denaturation on the film-forming performances of soybean protein isolate (SPI) and elucidate the underlying mechanisms. From the results, glycerol had almost no effect on the protein’s secondary and tertiary structures. Indeed, the dispersion of glycerol diminished the intra- or intermolecular hydrogen bonding of SPI and interacted with the amino acids of subunits through hydrogen bonding and van der Waals forces. By interfering with protein network interactions, the glycerol molecule achieved a plasticizing effect on SPI films. The effects of heat treatment on SPI film properties were mainly realized through the changes in molecular conformation caused by protein denaturation, which manifested in the enhancement of light barrier and mechanical capabilities, and markedly altered the distribution of water states within the film network. This study provided valuable insights to clarify the mechanism of protein film formation.

Effects of phytic acid from soybean meal on Maillard reaction and antioxidant properties of products

This study used glycine (Gly), glucose (Glu), and soybean meal phytic acid (PA) as raw materials to investigate the effect of different PA addition amounts on the Gly-Glu Maillard reaction system and the antioxidant capacity of the products through rheological properties, particle size, chromatography, and other methods. The results showed that with the addition of PA, the apparent viscosity and average particle size of the system decreased, the thermal denaturation temperature increased, the product concentration decreased, the color became brighter, and the antioxidant performance was enhanced. This indicates that PA reacts with Gly and Glu to form PA - Gly and PA - Glu complexes, respectively, and hinders the Maillard reaction. This work demonstrates the potential application value of soybean meal PA in controlling the Maillard reaction.