Black rice is rich in bran layer polyphenols, which enhance bioactivity but may reduce its consumer acceptability due to astringency. Polyphenol-salivary protein aggregation is the molecular basis of astringency. In this study, a saliva-induced precipitation approach with liquid chromatography-tandem mass spectrometry was used to identify protocatechuic acid (PA) as the key astringent component in black rice, accounting for 68% of total precipitated polyphenols. With α-amylase as a representative, the PA-salivary protein interaction was analyzed using fluorescence spectroscopy, isothermal titration calorimetry (ITC), and molecular docking. Fluorescence spectroscopy showed a quenching constant (K q) of 7.8451 × 1011 L⋅mol-1⋅s-1, and ITC revealed a binding constant (K) of 2.65 × 103 L/mol with 1.32 binding sites, indicating the interaction was characterized by strong, spontaneous, noncovalent binding, static quenching, and multiple binding sites. Atomic force microscopy, contact angle, and small amplitude oscillatory shear rheology revealed that PA increased salivary film surface roughness (contact angle from 36.2° to 43.3°) and weakened viscoelasticity, thereby facilitating film rupture and loss of lubrication underlying astringency perception through tactile stimulus pathway. Molecular dynamics simulations further revealed stable PA binding to human astringency receptor human taste 2 receptor member 16 (hTAS2R16), indicating an additional astringency perception gustatory pathway.

The effects of three kinds of sugar alcohols (xylitol, lacttol and erythritol) composited moist heat treatment on the thermosolubility, thermodynamic, gelatinization, rheology, crystallinity, digestion and microstructure of glutinous rice flour were investigated. After adding sugar alcohol, swelling power, solubility, gelatinization enthalpy and viscosity, disintegration and retrogradation value, gel elasticity, long-term orderliness, resistant starch and strongly bound water content, and layer thickness of gel micro lamellar structure of glutinous rice flour significantly increased. Under the synergistic effect of sugar alcohol and moist heat treatment, the swelling power and solubility of glutinous rice flour was significantly lower than that of sugar alcohol and glutinous rice flour mixed system while the peak gelatinization viscosity, disintegration and recovery value and gel hardness were significantly higher than those of sugar alcohol and glutinous rice flour mixed system. The elasticity and consistency coefficient of gel were significantly lower than those of sugar alcohol and glutinous rice flour mixed system. The combine of moist heat treatment and sugar alcohol can cooperate to enhance the thermodynamic properties, gelatinization properties, rheological properties and microstructure of glutinous rice flour to different degrees, and provide a reference for the quality improvement of glutinous rice flour and the development of glutinous rice flour products.

This study aimed to construct a "cold/hot" inverse co-coagulation gel system using gelatin (GA) and curdlan (CUD) to regulate the composite gel performance. The effects of CUD concentration (0, 0.1, 0.2, 0.4, 0.6, and 0.8 wt%) on the intermolecular interaction, microstructure, gel properties, and rheological properties of the composite gels were systematically investigated. Moderate CUD incorporation (0.1-0.4 wt%) significantly improved gel performance, with gel strength increasing by 1.04 N, storage modulus (G ') increasing 3-fold, and water-holding capacity (WHC) improving by 6%. In addition, 0.4% CUD/GA system maintained a lower and more stable tan theta plateau in the melting region, indicating improved viscoelastic stability during thermal transition. The mass fractal dimension reached a maximum value of 2.64 +/- 0.04 at 0.4% CUD, suggesting the formation of a denser and more structurally integrated network. This improvement was attributed to a temperature-dependent sequential gelation: heat-induced hydrophobic self-assembly of CUD into micro-domains, followed by cooling-driven GA triple-helix network formation as the continuous phase, which immobilized the CUD micro-domains. Intermolecular hydrogen bonding further immobilized the dispersed CUD domains within the GA matrix, promoting the formation of a dense and homogeneous semi-interpenetrating polymer network. However, excessive CUD (>= 0.6%) addition induced a transition from co-assembly to competitive polysaccharide self-aggregation, resulting in microphase separation. The structural heterogeneity, evidenced by increased turbidity and pore coarsening, ultimately deteriorated the WHC and gel properties. These findings elucidate the molecular mechanism and macro-performance of CUD/GA composite gel, providing a theoretical basis for designing cold/hot inverse co-coagulation composite gels.

The astringency in green tea primarily originates from gallate-type and non-gallate-type catechins. Epigallocatechin gallate (EGCG) is a gallate-type catechin, which has a strong astringency and is the most abundant catechin in tea. Unlike EGCG, epigallocatechin (EGC) has one fewer galloyl group on the C3 oxygen atom and exhibits a weaker astringency. Taking EGCG and EGC as representative catechins, this study investigated the effects of the galloyl group on their astringency. The interactions of EGCG and EGC with salivary proteins were qualitatively and quantitatively analyzed using fluorescence spectroscopy, isothermal titration calorimetry, and molecular docking. The surface roughness and viscoelasticity of the salivary film were then studied to relate the molecular interactions and perceived astringency. Additionally, the bindings of EGCG and EGC to astringency receptor proteins were also simulated. The results revealed that the galloyl group enabled the EGCG-promoted aggregation of salivary proteins, resulting in a stronger astringency through both tactile and gustatory pathways. In contrast, EGC exhibited a weaker astringency only through the gustatory pathway.

The effects of wheat bran dietary fiber (WBDF) treated by air flow micro-pulverization on gelatinization, thermal, rheological, structural properties, and in vitro digestion of wheat starch (WS) were investigated. Different particle sizes of WBDF were obtained by conventional knife grinding and airflow micro-grinding. Compared with conventional knife grinding, the particle size of WBDF treated by air flow micro-pulverization decreased, the particle size distribution was concentrated at small particle sizes, the specific surface area increased, and the hydraulic and oil-holding power decreased, which was mainly related to the change of WBDF spatial structure and the increase of solubility. At the same time, the peak viscosity, setback, breakdown, and resistant starch content short-range order degree and relative crystallinity of WS were increased by adding WBDF treated by air flow micro-pulverization, whereas the gelatinization enthalpy value and apparent viscosity were decreased. This indicated that the air micro pulverized WBDF promoted gelatinization and inhibited digestion while reducing the thermal stability of WS, leading to short-term recovery. This study provides a theoretical reference for the production and processing of gluten-containing flour products. PRACTICAL APPLICATION: In this study, the physical and chemical properties and spatial structure of air flow micro pulverized dietary fiber of wheat bran were analyzed, and its effects on the properties of wheat starch were studied. Therefore, this study provides a theoretical basis for the industrial application of gluten-containing flour products.

The strong hydrophilicity of corn starch nanoparticles (CSNPs) limits their application as a Pickering emulsion gel stabilizer. In this study, CSNPs were modified with purple corn cob anthocyanins (PCCAs), a type of anthocyanin derived from processing waste. Fourier transform infrared spectroscopy and X-ray diffraction analyses confirmed that PCCAs were embedded in CSNPs via both hydrogen bonding and hydrophobic interactions. The three-phase contact angle increased from 51.77 ± 3.18° to 67.43 ± 1.08° after loading, suggesting the PCCA-modified CSNPs (PCCA-CSNPs) were more suitable than the CSNPs for stabilizing oil/water emulsion. The Pickering emulsion gel stabilized by PCCA-CSNPs (PCSPEGs) exhibited better storage stability than the Pickering emulsion gel stabilized by CSNPs (CSPEGs). A comparison of the rheological properties, creep-recovery properties, and interfacial properties between CSPEGs and PCSPEGs revealed that the combined effects of the more stable interfacial layer and the increased viscosity of the continuous phase of the emulsion gel contributed to the improved stability of PCSPEGs. Thus, PCCA-CSNPs represent a green, rapid, and economical hydrophobic modification method for CSNPs, and the stabilization mechanism of PCSPEGs was elucidated in this work.

This study evaluated the impact of defatted rice bran (DRB) particle sizes (103.67–6.04 μm) on the gel properties and flavor of silver carp surimi gels.

The influence of airflow impact milling (AFIM) on the particle size, physicochemical properties, microstructure, and flavor of defatted rice bran was investigated. With the decrease of feed speed and the increase of milling times, AFIM reduced the average particle size of defatted rice bran to a maximum of about 6.04 mu m. At this time, its whiteness and soluble dietary fiber content increased by 17% and 36.6%, respectively, and the insoluble dietary fiber content decreased by 16.4%. AFIM increased the cation exchange capacity, water solubility index, and swelling capacity of defatted rice bran, but decreased the water and oil holding capacities. Moreover, scanning electron microscopy results showed that AFIM changed the microstructure of defatted rice bran to provide the ultrafine powders with good uniformity. A total of 37 volatile substances in defatted rice bran were identified by GC-IMS. The release of aromatic odors such as fruit, nutty, and sweet aromas from defatted rice bran after AFIM increased, improving its flavor quality.

Three-dimensional (3D) printing is a powerful method to fabricate customized food with various shapes and precise nutrient contents. The rheological properties of food inks are key parameters for 3D printing. In this study, four kinds of alginates (M1G2, M2G1, SAlow, and SAhigh) were selected with different beta-D-mannuronic acid (M) to alpha-L-guluronic acids (G) ratios or molecular weights as a model to prepare hydrogels, and correlation analysis between the molecular characteristics, rheological properties, and printability was performed. The viscoelasticity, thixotropy, water distribution, and printing performance were investigated using a rheometer, low-field nuclear magnetic resonance, and micro-computed tomography. The results showed that the ratio of calcium to guluronic acid in the printable regions of the M1G2, M2G1, and SAhigh groups fluctuated in a small range 0.23-0.30, which indicated that the homogeneity of the gel was a prerequisite. Smooth extrusion was obtained when the gel strength ranged from 450 to 800 Pa. When the G ' 3/G ' 1 recovery was above 90%, hydrogels could maintain satisfactory self-supporting capacities after printing. A positive correlation between the printing edge deviation (sigma n) and phase angle (delta) or relaxation time of capillary water (T22) that the gel network density and water-binding ability were key factors. These data provide theoretical support for the prediction and orientation design of hydrocolloid-based 3D printed inks in food.

This paper presents the establishment of a sensory evaluation system for purple sweet potato rice steamed sponge cake (PSPRSSC) utilizing fuzzy mathematics. Initially, eight key sensory evaluation indices were identified through expert consultations. These indices were subsequently prioritized using fuzzy binary comparison, resulting in the following order: aroma, taste, crust color, elasticity, viscosity, chewiness, hardness, and brightness. The corresponding weight values assigned to each index were 23%, 18%, 16%, 13%, 12%, 8%, 6%, and 4%, respectively. Notably, aroma was found to have a more significant impact than visual attributes in the sensory evaluation of PSPRSSC. Based on this prioritization, comprehensive sensory evaluation criteria for PSPRSSC were formulated. Verification tests confirmed the efficacy of the proposed evaluation system. This study provides critical data and theoretical support for the sensory quality assessment of PSPRSSC, thereby facilitating its industrialization and enhancing its market viability.

In an effort to provide a theoretical basis and data reference for the efficient processing and utilization of peanuts,changes in the moisture content,browning degree,particle texture parameters,water state and distribution,and protein denaturation degree of peanuts before and after microwave pretreatment were investigated,as well as the effect of microwave pretreatment on the yield of screw-pressed peanut oil.The results were compared with those obtained using vacuum oven drying.Meanwhile,for each pretreatment,the Pearson correlation between oil yield and moisture content,browning index(BI),particle texture parameters,water state,and protein denaturation degree was determined.The results showed that after microwave treatment for 7 min at 900 W or vacuum oven treatment at 85 ℃ for 89 min,the moisture content of peanuts decreased from 5.25％to 2.27％,with the highest oil yields of 45.85％and 45.76％being obtained,respectively.Under these conditions,the shear stress formed between peanuts and the oil press was moderate,peanuts were fully squeezed and deformed,with a large amount of oil flowing out,and peanuts had the best plasticity,the most ideal moisture state and a moderate degree of protein denaturation,so that not only a large amount of oil flowed out,but also peanuts were not easily broken,thus not affecting the formation of peanut cake.

Xylitol with different content(0%～25%)was added to glutinous rice flour to construct a xylitol-glutinous rice flour blend system to investigate the effects of xylitol on the gelatinization properties,thermodynamic properties,gel texture,rheology properties and digestion properties of glutinous rice flour,as well as on the quality of rice dumpling made from xylitol-glutinous rice flour.The results showed that the addition of xylitol increased the gelatinization temperature,peak viscosity and final viscosity of the xylitol-glutinous rice flour,while reduced the degree of short-range order of xylitol-glutinous rice flour.The xylitol-glutinous rice flour system behaved as a pseudoplastic fluid with shear thinning behavior.Compared with the control group,when the addition of xylitol was 10%,the xylitol-glutinous rice flour blend system had the smallest retrogradation value and gel hardness,which were 405 cP and 14.952 g,respectively.At this time,the content of resistant starch in the system was 29.88%,showing good retrogradation resistance.However,high content of xylitol(15%～25%)promoted the short-term regeneration of the xylitol-glutinous rice flour blend system,increasing its regeneration value and elasticity.Furthermore,the addition of xylitol significantly reduced the water loss rate and juice permeability of rice dumpling made of xylitol glutinous rice flour.Rice dumpling made of glutinous rice flour with 10%xylitol had high hardness,elasticity,resilience and chewability,and its eating quality was the best.This study provides a theoretical and technical references for the improvement of the quality of glutinous rice flour through xylitol and the product development of glutinous rice flour.

The astringency of green tea is an integrated result of the synergic and antagonistic effects of individual tea components, whose mechanism is highly complex and not completely understood. Herein, we used an epigallocatechin gallate (EGCG)/caffeine (CAF)/saliva model to simulate the oral conditions during tea drinking. The effect of CAF on the interaction between EGCG and salivary proteins was first investigated using molecular docking and isothermal titration calorimetry (ITC). Then, the rheological properties and the micro-network structure of saliva were studied to relate the molecular interactions and perceived astringency. The results revealed that CAF partially occupied the binding sites of EGCG to salivary proteins, inhibiting their interaction and causing changes in the elastic network structure of the salivary film, thereby reducing astringency.

Weizmannia coagulans with high temperature tolerance and stability was selected for the production of exopolysaccharides (EPS) at the fermentation temperature of 52 & DEG;C. The weak basic anion exchange resin was employed in the fermentation for the construction of buffer system to neutralize some lactic acid and form intermolecular hydrogen bonds with hydroxyl groups on capsular polysaccharides of bacteria via tertiary amine groups, resulting in the increased growth space for capsular polysaccharides. In addition, the fermentation at relatively high temperature significantly decreased the adsorption of Ca2} derived from CaO used for pH adjustment to the resin and sustained the ion exchange capability of the resin available for the formation of intermolecular hydrogen bonds with capsular polysaccharides. The concentration of EPS obtained achieved up to 19.8 g/L, which was increased by approximately 20-fold as compared to the concentration of EPS obtained by conventional fermentation. The conversion rate of carbohydrates to EPS reached up to 35.1%. The EPS produced under the optimized fermentation condition included neutral and acidic heteropolysaccharides with a molecular mass of 3.4 x 104-1.5 x 106 Da. The concentration and molecular mass distribution of EPS exhibited good reproducibility. This study provides a novel method for the industrial production of EPS.

In this study, Ca2+-induced sodium alginate hydrogel was used as a model. The rheological properties were measured via steady-state shear, oscillation strain sweep, and yield stress. The network of sodium alginate hydrogels was analyzed using water distribution and rheological parameters. After a comprehensive analysis of the morphology and Micro-CT structure of 3D printing products, the mathematical relationship between rheological parameters and 3D printing effect was established using the Spearman's correlation analysis. The results showed that the highest score of 3D printing product was prepared at the mass ratio of SA to Ca2+ at 24:1 and the concentration of SA at 4.5%. At the same time, the filament structure of 3D printing product was fine and the porosity was 12.21%. Rheological parameters of K, η1, G', G", τ0 and τy were 255.1 Pa·sn, 2740 Pa·s, 3509 Pa, 673.2 Pa, 261.4 Pa, and 51.62 Pa, respectively. The capillary water (about 99.20%) was dominant in the gel network, showing strong water holding capacity of hydrogel. Results of correlation analysis showed that the viscosity properties (K, η1, and G") were negatively correlated with the extrudability, and the correlation coefficient was -0.577. The self-supporting capacity of the 3D printing product was positively correlated with the elastic modulus and stress (G', τ0, and τy) (P<0.05).

Kaempferitrin was extracted from leaves of Prunus cerasifera with an average yield of 1.3 +/- 0.18% (n = 20). The purity of the product was over 98.5% as determined by high-performance liquid chromatography. Dried and smashed leaves of P. cerasifera were subjected to extraction with 70% ethanol (vol/vol) at room temperature and the extract was concentrated by vacuum evaporation. The extract was separated using nonpolar and medium polar macroporous resin in series. The post-column collecting solution was concentrated under reduced pressure and its product was obtained through secondary crystallization. Kaempferitrin obtained was structurally analyzed and characterized. The absorption of kaempferitrin to macroporous resin was analyzed thermodynamically and kinetically to determine its melting and turbidity point. After purification of mother liquor, the recovery rate was over 70%. Practical Applications Prunus cerasifera is a plant resource that has yet to be tapped. Kaempferitrin in its leaves, with a content of 1.8-2.2%, is an important bioactive substance. Pharmacologically, kaempferitrin induces immune reactions in vitro, stimulates the secretion of adiponectin in adipocytes, elicits apoptosis, and possess antitumor effects. Separation of kaempferitrin from P. cerasifera leaves using the macroporous resin double-column system is cost-effective and simple. Moreover, the method can achieve high extraction efficiency. After crystallization, the purity was higher than 98.5%. The technology can be widely used in the preparation processes of medical agents. In addition, the results showed that the optimized parameters can be applied to the parameter prediction of related designs.

根据食品工程专业培养方案及学科特点,充分利用高校教学改革契机,从整合教学内容、创新教学方法、多手段丰富课程内容、提升实验科研能力、改革考核方式入手,设计合理的仪器分析教学模式并进行实践,取得了良好的教学效果.

Comparative molecular field analysis and comparative molecular similarity indices analysis were employed to analyze the antiwear properties of a series of 57 esters as potential lubricant-based oils. Predictive 3D-quantitative structure tribo-ability relationship models were established using the SYBYL multifit molecular alignment rule with a training set and a test set. The optimum models were all shown to be statistically significant with cross-validated coefficients q 2 > 0.5 and conventional coefficients r 2 > 0.9, indicating that the models are sufficiently reliable for activity prediction, and may be useful in the design of novel ester-based oils.

评价枸杞子、桑椹、桑叶水提物和叶黄素联合干预对光损伤视网膜的保护作用.75只小鼠分为正常对照组、模型对照组和低、中、高剂量给药组,采用自制光照箱进行造模,检测视网膜组织外核层厚度以及SOD、GSH-Px、CAT和T-AOC活力以及MDA含量.结果表明,光照导致小鼠视网膜组织外核层厚度显著下降,视网膜中SOD、GSH-Px、CAT和T-AOC活力显著下降,MDA含量显著增加.摄入低、中、高剂量受试物后,与模型对照组相比,视网膜外核层厚度增加11.7％、26.2％和35.2％,MDA含量分别降低19.2％、58.8％和84.5％,SOD活力分别增加26.8％、31.2％和57.8％,CAT活力分别增加33.3％、48.0％和81.3％,GSH-Px活力分别增加18.3％、50.8％和53.7％,T-AOC活力分别增加23.1％、53.8％和69.2％,其中,中、高剂量组具有显著性差异(P＜0.05).由此可见,枸杞子、桑椹、桑叶水提物和叶黄素联合干预对视网膜光损伤小鼠具有显著保护作用.

采用微波消解油脂,并结合抗坏血酸-钼蓝比色法测定油脂中磷含量.结果表明,此方法生成的磷钼蓝最大吸收波长为821 nm;当抗坏血酸溶液添加量为0.700 mL,水浴温度为90℃,水浴时间为6 rmin时,显色体系较稳定,无机磷含量在0 ～0.25μg/mL时,显色液的吸光度符合比耳定律,其回归方程为y=70.426x-0.000 2,相关系数R2 =1;洗涤和赶酸操作对油脂消化液中磷回收有显著影响;此方法准确度和可靠性较好,加标回收率为96.25％～105.00％,变异系数为3.24％,与国标方法(GB/T 5537-2008)比较平均偏差仅为1.18 mg/kg,具有所需样品量少,省时省力等优点.