This study investigated the effects of high hydrostatic pressure (HHP) treatment on the physicochemical properties and microstructure of frozen pea protein gels and elucidated the underlying gelation mechanisms. Heat-induced pea protein gels were subjected to three HHP conditions (100, 300, and 600 MPa for 15 min each) and evaluated in terms of their color, textural attributes, solubility, and subunit composition before and after freezing. Compared with the native pea protein isolate (PPI), HHP-treated gels demonstrated significantly reduced gel hardness, which gradually declined as pressure increased. Dynamic rheological analysis revealed that HHP-treated gels exhibited enhanced elasticity and viscosity, accompanied with a dense and highly homogeneous network structure. The subunit composition involved in gel formation changed notably after HHP treatment, and the number of participating proteins and the content of free sulfhydryl groups decreased with increasing pressure (100 MPa<300 MPa100 MPa>PPI>300 MPa. Dynamic rheological results further confirmed that in all samples, the storage modulus exceeded the loss modulus, indicating a predominantly elastic gel network. Freezing disrupted the gel structure under all treatments, reducing surface smoothness, and gel hardness before and after freezing decreased progressively with increasing pressure. Soluble protein content followed the order of 100 MPa<300 MPa

This study systematically investigated the influence and underlying mechanism of Hofmeister cationic salts (KCl, NaCl, MgCl2, and CaCl2 at 1 % w/w) on the physicochemical, structural, and digestive properties of pea protein isolate (PPI)-based meat analogs produced by high-moisture extrusion. Results demonstrated that all salts significantly enhanced the viscoelasticity of the protein melt, hardness, chewiness, and density of the extrudates, but decreased the in vitro protein digestibility (IVPD), following the specific order of the Hofmeister cation series: K+ < Na+ < Mg2+ < Ca2+. Conversely, the improvements in tensile resistance force, fibrous degree and moisture content followed the order of K+ > Na+ > Mg2+ > Ca2+. Mechanistic insights revealed that chaotropic ions (Mg2+/Ca2+) promoted protein aggregation primarily through enhanced hydrophobic interactions, and increased beta-turn structures by 5.33 %-6.55 %, leading to the formation of packed domains and rigid structures in extrudates with higher hardness (39.06-43.29 kg) but lower IVPD (60.51-65.00 %). In contrast, kosmotropic ions (K+/Na+) more effectively facilitated hydrogen bonding and the conversion of alpha-helices to beta-sheets, resulting in the generation of more obvious anisotropic fibrous structures. These findings provided a theoretical basis for the precise texture design in plant-based meat analogs through rational cation selection.

This study investigated the effects of different charged polysaccharides, including cationic chitosan (CS), neutral konjac glucomannan (KGM) and guar gum (GG), and anionic kappa-carrageenan (CA) and sodium alginate (SA), on the gelation properties and in vitro digestibility of potato protein isolate (PPI) gel. The results showed that anionic polysaccharides (CA and SA) were most effective in increasing the WHC (approximately 30%) and texture properties of composite gels, followed by neutral polysaccharides (KGM and GG) and then cationic CS. The anionic polysaccharides (CA and SA) showed the greatest effect on increasing the absolute zeta potential, inducing the exposure of hydrophobic groups, enhancing the hydrophobic interactions, and promoting the generation of beta-sheet structures, thus contributing to the formation of fine and well-organized gel network. By contrast, the electrostatic neutralization between cationic CS and negatively charged PPI molecules under the neutral environment accelerated the protein self-aggregation, thus structuring dense protein domains and nonhomogeneous network structures. It also resulted in the greatest reduction in the protein digestibility (from 82.23% to 77.33%). The neutral KGM/GG caused no significant changes in zeta potential but led to the most prominent enhancement in the hydrogen bonding, which contributed to the generation of uniform and continuous microstructures with regular large pores. This study provided a new perspective to understanding the regulation and improvement of the quality of plant protein-based gel foods by controlling the ionic types of added polysaccharides.

This study investigated the mechanisms and variations in physicochemical properties and microstructures of potato protein gels at different pH levels under freezing conditions. Potato protein gels with a 15 % protein concentration were prepared at pH 2, pH 7, and pH 10. The results showed that at pH 7, the gel exhibited roughness, pronounced granularity, a uniform pore size distribution, and a water-holding capacity of 97.12 %. After freezing, the enthalpy was -228.13 J/g, leading to significant changes in moisture distribution and a reduction in water-holding capacity to 80.43 %. At pH 10, increased hydrogen bonding (8.58 %) and ionic bonding (2.03 %) contributed to a denser, more ordered mesh structure with an enhanced water-holding capacity (97.88 %). The enthalpy was -227.85 J/g, which minimized moisture distribution changes and preserved a high water-holding capacity after freezing. In contrast, at pH 2, the gel exhibited a coarse and non-uniform structure, with a reduced water-holding capacity of 67.55 %, increased enthalpy of -243.45 J/g, and elongated relaxation time. The freezing process led to ice crystal formation, which disrupted the protein network, particularly at lower pH levels. These findings offer a theoretical basis for optimizing potato protein gel structures and advancing the development of innovative potato-based products.

The industrial application of pea protein is limited due to its poor gelation properties. This study aimed to evaluate the effects of psyllium husk powder (PHP) on improving the rheological, textural, and structural properties of heat-induced pea protein isolate (PPI) gel. Scanning electron microscopy (SEM), intermolecular forces analysis, the quantification of the surface hydrophobicity and free amino groups, and Fourier transform infrared spectroscopy (FTIR) were conducted to reveal the inner structures of PPI-PHP composite gels, conformational changes, and molecular interactions during gelation, thereby clarifying the underlying mechanism. The results showed that moderate levels of PHP (0.5–2.0%) improved the textural properties, water holding capacity (WHC), whiteness, and viscoelasticity of PPI gel in a dose-dependent manner, with the WHC (92.60 ± 1.01%) and hardness (1.19 ± 0.02 N) peaking at 2.0%. PHP significantly increased surface hydrophobicity and enhanced hydrophobic interactions, hydrogen bonding, and electrostatic interactions in PPI-PHP composite gels. Moreover, the electrostatic repulsion between anionic PHP and negatively charged PPI in a neutral environment prevented the rapid and random aggregation of proteins, thereby promoting the formation of a well-organized gel network with more β-sheet structures. However, the self-aggregation of excessive PHP (3.0%) weakened molecular interactions and disrupted the continuity of protein networks, slightly reducing the gel strength. Overall, PHP emerged as an effective natural gel enhancer for the production of pea protein gel products. This study provides technical support for the development of innovative plant protein-based foods with strong gel properties and enriched dietary fiber content.

To investigate the effect of autoclaving treatment modifications on the multi-scale structure and physicochemical properties of yellow rice starch,a comparative analysis of the multi-scale structure(morphology structure,crystal structure,and molecular chain structure)and gelatinization characteristics were conducted on the pre-and post-modified starch using high-performance anion exchange chromatography,X-ray diffraction,infrared spectroscopy,scanning electron microscopy,differential scanning calorimetry,and rapid viscosity analyzer.The results showed that autoclaving treatment modifications did not significantly alter the total starch content of yellow rice starch.However,the content of amylose increased from 7.46％to 8.28％.In comparison to the original starch,the modified yellow rice starch exhibited an increase in the proportion of short chains,while the proportions of medium and long chains significantly(P＜0.05)decreased.The weight-average molecular mass,radius of gyration,and polydispersity index of starch significantly(P＜0.05)increased,while the Mn value significantly(P＜0.05)decreased.The microstructure of yellow rice starch underwent significant changes from its original granular form to a flaky form with a rough surface and pore-shaped depressions after autoclaving treatment modifications.The results of infrared and X-ray diffraction patterns indicated that new functional groups were not generated in the autoclaved yellow rice starch compared to the original starch.However,the crystal structure of yellow rice starch was destroyed with a transition from the A-type to an amorphous configuration.In comparison to the original yellow rice starch,the autoclaved yellow rice starch exhibited enhanced heat stability,shear resistance,and cold paste stability,and it was less prone to retrogradation and aging.After autoclaving treatment modifications,the porosity of yellow rice starch decreased,and the glass transition temperature range narrowed.The autoclaving treatment modification has a significant impact on the multi-scale structure and gelatinization characteristics of yellow rice starch,providing a theoretical basis for further deep processing of yellow rice.

This study investigated the effect of inulin with different polymerization degrees (DP), including L-inulin (DP 2–6), M-inulin (DP 10–23) and H-inulin (DP 23–46), on the structural and gelation properties of potato protein isolate (PPI). Results revealed that textural properties (hardness, cohesiveness, springiness and chewiness) and water-holding capacity (WHC) of PPI-inulin composite gels were positively correlated with the inulin DP and addition content at 0–1.5% (w/v), but deteriorated at 2% due to phase separation. The addition of 1.5% H-inulin showed the most significant increment effects on the WHC (18.65%) and hardness (2.84 N) of PPI gel. Furthermore, M-/H-inulin were more effective in increasing the whiteness and surface hydrophobicity, as well as in strengthening hydrogen bonds and hydrophobic interactions than L-inulin. Fourier transform infrared spectroscopy analysis and microstructural observation indicated that inulin with higher DP promoted more generation of β-sheet structures, and leading to the formation of stronger and finer network structures.

This study aimed to analyze the dynamic evolution of physicochemical properties and microstructure in soybean protein gels subjected to freezing conditions. SPI, 7S, and 11S were used in experiments. A 12g/100g protein gel was formulated after 1 and 5 days of freezing. Subsequent determination and analysis encompassed various indices, including texture, subunit composition, sulfhydryl group content, water distribution, and microstructure. The findings revealed a significant increase in the hardness of SPI, 7S, and 11S protein gels with prolonged freezing time. The 11S gel exhibited the most substantial increase, followed by SPI and 7S. And the decreases in the water-holding properties of the protein gels were 10.08%, 1.19%, and 49.34%, with the largest decrease in the water-holding properties of the 11S protein gels. Conversely, the water-holding capacity and total sulfhydryl content of SPI, 7S, and 11S protein gels decreased over time during freezing. Subunit distribution analysis indicated darker bands at the top of concentrated and separation gels. The freezing process induced the formation and growth of ice crystals, altering the spatial network structure of protein gels. Consequently, the proportion of free water in all three soybean protein gels increased, leading to enhanced mobility and a looser network structure.

A novel peptide (VSAAAA) was obtained after the isolation, purification, and identification of millet gliadin. In order to explore the anti-inflammatory effect of peptide VSAAAA in vivo, the peptide VSAAAA was administered in the first three weeks, and ulcerative colitis was induced in mice with DSS aqueous solution in the last week. Results showed that the disease activity index and histopathological changes in the colon were significantly reduced after VSAAAAA intervention. The expression levels of serum proinflammatory cytokines in mice were significantly reduced. In addition, VSAAAA gavage significantly alleviated decrease in the expression levels of the intestinal nexus proteins ZO-1 and occludin and increase in the expression levels of p65 and p-p65 proteins in the NF-κB signaling pathway. Moreover, the intestinal flora composition of colitis mice was regulated by decreasing the relative abundance of harmful bacteria (Firmicutes) and increasing the relative abundant of beneficial bacteria (Bacteroides).

To investigate the impact of frozen storage conditions on the physicochemical properties of soybean protein and explore the underlying mechanisms, this study focused on soybean isolate (SPI), ß-soybean companion globulin (7S), and soybean globulin (11S). The protein solutions were prepared at a concentration of 2% and subjected to freezing for 1 and 5 days. Subsequently, the protein content, physicochemical properties, secondary structure, sulfhydryl content, and chemical interaction forces were assessed and analyzed using UV spectrophotometry, Zeta potential measurements, SDS-PAGE, Fourier infrared spectroscopy, and endogenous fluorescence photoemission spectroscopy. The obtained results revealed that the solubility and total sulfhydryl content of SPI, 7S, and 11S exhibited a decreasing trend with prolonged freezing time. Among them, 11S demonstrated the largest decrease in solubility and total sulfhydryl content, followed by SPI, and 7S the least. During freezing, the aromatic amino acids of SPI, 7S, and 11S molecules were exposed, leading to increased hydrophobicity, protein aggregation, and particle size enlargement, and the structure of the protein changed from disordered structure to ordered structure. After freezing, the polarity of the microenvironment of SPI, 7S, and 11S increased, and their maximum fluorescence emission wavelengths were red-shifted. Notably, the largest red shift of SPI was from 332 nm to 335 nm. As freezing time increased, the contribution of hydrogen bonding increased, while the contribution of hydrophobic interactions decreased. This indicates that freezing affects the hydrophobic interactions, hydrogen bonding, and other chemical forces of the protein. The growth of ice crystals leads to the unfolding of protein molecular chains, exposure of internal hydrophobic groups, enhancement of hydrophobicity, and alters the secondary structure of the protein.

Background and Objectives Pulsed electric field (PEF) treatment is currently a hot spot in food science research. The improvement and regulation of protein structure and physicochemical properties after PEF treatment are a new development in its processing technology. This study aimed to clarify the effects of moderate-intensity PEF treatment on the structure and physicochemical properties of foxtail millet (Setaria italica) prolamin and its action rules. Findings PEF treatment changed the spatial conformation of millet prolamin, increased its hydrophobicity and solubility in alcohol solution, but did not change the subunit composition distribution. It also promoted the increase in soluble aggregates, resulting in an increase in protein particle size. The alpha-helix content of the protein decreased, the beta-sheet content increased, the number of disulfide bonds increased, and the protein structure became more orderly after treatment. Conclusions The results showed that the structure and physicochemical properties of millet prolamin significantly changed after the moderate-intensity PEF treatment. Significance and Novelty The increased hydrophobicity of prolamin makes it a strong future candidate in medicinal excipients, food packaging materials, and biodegradable polymers.

以内酯豆腐为研究对象,在豆浆中添加不同比例(0.2％、0.3％、0.4％)的δ-葡萄糖酸内酯(GDL),通过质构仪、SDS-PAGE、红外光谱、激光扫描共聚焦显微镜等仪器,对其组织结构、含水量和保水性、凝胶作用力组成、蛋白质亚基组成、二级结构和微观结构进行测定,分析GDL添加量对豆腐凝胶特性的影响.结果表明,随着GDL添加量的增加,其硬度、弹性和咀嚼性显著提高(P<0.05),当GDL添加量为0.4％时,保水性最好,达到了83.38％,豆腐中疏水作用逐渐增强,可溶性蛋白的亚基条带逐渐减少,蛋白质向凝胶转化的趋势增大,豆腐蛋白质中β-折叠含量由31.93％增加到38.43％,无规则卷曲含量由13.93％下降到13.78％.

To explore the effect of micronization on the structural, functional, and antioxidant properties of wheat bran, wheat bran with mean particle size (D50) of 46.08, 34.29, 26.51, 26.35, and 26.05 μm were prepared by using an ultrafine pulverizer under different rolling frequencies (0, 6, 9, 12, and 15 times). The main chemical components and structural, functional, and antioxidant properties of the wheat bran were compared and a correlation analysis was conducted. As the D50 of the wheat bran decreased from 46.08 μm to 26.05 μm, the micromorphology exhibited the destruction of the bundle structure, which is formed by starch and fiber, during which the starch particles peeled off, the fiber fragments destructed, and some of the slim fiber fragments attached to the surfaces of the starch granules. According to the X-ray diffraction pattern, part of the crystalline structure was transformed into an amorphous structure and the crystallization index decreased from 13.08% to 3.95%. According to the near-infrared spectrum, more active groups, such as the hydroxyl group, were exposed; however, no new groups were generated. These structural changes accordingly caused changes in the chemical components, functional properties, and antioxidant properties of the wheat bran. Specifically, the protein, total phenols, total flavonoids, and fatty acid content increased by 6.72%, 23.47%, 19.07%, and 172.88%, respectively. The lipase activity, antioxidant activity in vitro (DPPH• scavenging activity, ABTS+• scavenging activity, and ferric reducing antioxidant power), and the water-holding, cholesterol-adsorption, sodium nitrite-adsorption, and cation-exchange capacities, were enhanced to some extent. The oil-holding capacity decreased from 3.01 g/g to 1.32 g/g. The swelling capacity decreased first and then increased and the swelling capacity of the wheat bran with a D50 of 34.29 μm was the lowest (3.62 mL/g). Therefore, the micronization could be used as a pretreatment method to improve the functional and antioxidant properties of wheat bran; however, the optimal particle size of wheat bran is based on the function of the product.

The kafirin derived from Jin Nuo 3 sorghum underwent a high-hydrostatic-pressure (HHP) treatment of 100, 300, and 600 MPa for 10 min to investigate alterations in its physicochemical attributes. The findings exhibited a reduction in protein solubility, declining from 83% to 62%, consequent to the application of the HHP treatment. However, this treatment did not lead to subunit-specific aggregation. The absorption intensity of UV light diminished, and the peak fluorescence absorption wavelength exhibited a shift from 342 nm to 344 nm, indicating an increased polarity within the amino acid microenvironment. In an aqueous solution, the specific surface area expanded from 294.2 m2/kg to 304.5 m2/kg, while the average particle-size value in a 70% ethanol solution rose to 26.3 nm. Conversely, the zeta-potential value decreased from 3.4 mV to 1.3 mV, suggesting a propensity for aggregation in ethanol solutions. A notable rise in the intermolecular β-sheet content to 21.06% was observed, along with a shift in the peak denaturation temperature from 76.33 °C to 86.33 °C. Additionally, the content of disulfide bonds increased to 14.5 μmol/g. Collectively, the application of the HHP treatment not only enhanced the thermal stability but also induced a more ordered secondary structure within the kafirin.

Background: Recently, plant-based meat analogs have attracted extensive interest due to their contributions to environmental sustainability, animal welfare protection and health benefits. Lipids act as key determinants of the quality of plant-based meat analogs. However, little information is available regarding how plant oils in meat analogs provide sensory attributes and technological functions comparable to those of animal fats. Furthermore, the selection principle of lipids used in plant-based meat analogs remains insufficiently clear and experience dependent.Scope and approach: This review provides extensive insights into the lipid sources and their functional roles in plant-based meat analogs, and related molecular interactions to present systematic information about the biochemical and molecular principles behind industrial applications. Additionally, the applications, challenges, and perspectives of potential lipid replacers in plant-based meat analogs were assessed and highlighted. Key findings and conclusions: Exogenous lipids from oilseeds and tropical sources have been widely used in plantbased meat analogs, and endogenous lipids in less-refined plant protein ingredients have potential use in preparing clean-labeled meat analogs. These lipids play crucial roles as texture modifiers, juiciness enhancers, flavor providers, appearance modulators, lubricants and emulsifiers in plant-based meat analogs. The molecular interactions between lipids and other components during thermomechanical processing influence hydration dynamics, protein aggregation behavior and starch gelatinization, furtherly affecting the qualities of meat analog products. Fat replacers based on unique or modified carbohydrates, proteins, and synthetic lipids with low calories and desired functionalities are potential substitutes for lipids in meat analogs.

To determine parathion in cereals, hydrophilic and hydrophobic deep eutectic solvents (DESs) were used by digital image colorimetry with smartphones. In the solid-liquid extraction part, hydrophilic DESs were used as extractants to extract parathion from cereals. In the liquid-liquid microextraction part, hydrophobic DESs dissociated into terpineol and tetrabutylammonium bromide in situ. The dissociated hydrophilic tetrabutylammonium ions reacted with parathion extracted in hydrophilic DESs under alkaline conditions to produce a yellow product, which was extracted and concentrated by dispersed organic phase terpinol. Digital image colorimetry integrated with the use of a smartphone was used for quantitative analysis. The limit of detection and quantification were 0.003 mg kg-1 and 0.01 mg kg-1, respectively. The recoveries for parathion were 94.8-106.2% with a relative standard deviation less than 3.6%. The proposed method was applied to analyze parathion in cereal samples: the method has the potential to be applied to pesticide residue analysis in food products.

In this paper, an analysis method for chlorpyrifos (CPF) in cereal samples was proposed using dispersive liquid liquid microextraction combined with an enzyme-linked immunosorbent assay. In the dispersive liquid-liquid microextraction, deep eutectic solvents and fatty acids were used as solvents to extract, purify, and concentrate CPF in cereals. In the enzyme-linked immunosorbent assay, gold nanoparticles were utilized to enrich and conjugate more antibodies and horseradish peroxidase, while magnetic beads were used as solid supports to amplify the signal and shorten the detection time of CPF. The linearity range was 0.002-1 & mu;g kg 1, and the limit of detection was 0.0006 & mu;g kg 1. The extraction recoveries were 86.7-99.9% with a relative standard deviation of less than 7.0%. The proposed method was successfully used to analyze CPF in cereal samples (rice, wheat, maize, and millet) and has prospects for the pretreatment and detection of CPF residues in other food samples.

The main purpose of this study was to investigate the effects of HHP pressure on the structure and physicochemical properties of millet gliadin. The effects of HHP pressure on its physicochemical properties, structure, and conformation were systematically studied by ultraviolet second derivative spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy, and particle size analysis. HHP pressure treatment changed the spatial conformation of millet gliadin and increased the hydrophilicity of gliadin, but it did not alter the distribution of subunits. HHP pressure treatment changed the surface charge distribution of protein and increased the aggregation degree of protein, leading to the increase in protein particle size. After treatment, the α-helices and random coil ratio of the protein decreased, and some disulfide bonds formed, which made the protein structure more orderly and led to an increase in denaturation temperature. This phenomenon helped improve the limitation that millet gliadin cannot be directly used in the field of food production due to its strong hydrophobicity.

以大豆为主要原料,在豆浆中添加不同比例卤水(2.0％,3.5％和5.0％),通过质构仪、SDS-PAGE、傅里叶红外光谱及激光共聚焦等手段对卤水豆腐的质构、得率、蛋白含量、凝胶作用力、二级结构及微观结构等指标进行测定分析.结果表明:随着卤水添加量的增加,豆腐凝胶硬度呈上升趋势;卤水添加量2％时,豆腐含水量、保水性和得率均达到最高,分别为77.96％,46.85％和166.74％.豆腐的总蛋白含量随着卤水添加量的增加而增加.疏水作用和二硫键是卤水豆腐形成的主要作用力,二者含量达到80％.随着卤水含量的增加,β折叠含量从12.27％增加到13.61％;β转角含量从14.23％下降到13.2％,再升高至13.99％;α螺旋含量从53.1％下降至44.82％;无规则卷曲含量从20.41％上升到27.59％.

this paper, the preparation, purification, and identification of the antioxidant peptides of millet gliadin after high hydrostatic pressure (HHP) treatment were studied to broaden the utilization range of millet and provide certain theoretical basis for its further processing and utilization. Millet gliadin treated with 300 MPa was enzymatically hydrolyzed by pepsin, and the optimal hydrolysis time was determined to be 50 min by in-vitro antioxidant activity evaluation method [1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) free radical, hydroxyl radical, and superoxide anion scavenging activity]. The enzymatic hydrolysate was separated and purified by gel filtration and RP-HPLC, and the fraction with the strongest antioxidant activity (S4) was obtained. The scavenging ability of DPPH, center dot OH, and O-2 were 53.96% +/- 0.86%, 31.30% +/- 0.90%, and 52.73% +/- 0.99%, respectively. However, it still had lower antioxidant capacity compared with VC. Seven peptide sequences, namely, SLSHLTVQ, SLAHVTVQ, LHALTLQ, SGILAPSPVL, SHLTVQ, VSAAAA, and SPAAF, were identified from S4. The presence of certain amino acids, such as Glycine, Leucine, Phenylalanine, and Proline, is considered to induce high antioxidant activity against lipid peroxidation. Therefore, the antioxidant peptide extracted from millet gliadin after HHP treatment may be used as a natural antioxidant component in functional food.