Structural, physicochemical and digestive properties of non-covalent and covalent complexes of ultrasound treated soybean protein isolate with soybean isoflavone.

The non-covalent and covalent complexes of ultrasound treated soybean protein isolate (SPI) and soybean isoflavone (SI) were prepared, and the structure, physicochemical properties and in vitro digestion characteristics of SPI-SI complexes were investigated. Ultrasonic treatment increased the non-covalent and covalent binding degree of SPI with SI, and the 240 W ultrasonic covalent complexes had higher binding efficiency. Appropriate ultrasonic treatment caused more uniform particle size distribution, lower average particle size and higher surface charge, which enhanced the free sulfhydryl groups and surface hydrophobicity, thus improving the stability, solubility and emulsifying properties of complexes. Ultrasonic treatment resulted in more disordered secondary structure, tighter tertiary conformation, higher thermal stability and stronger SPI-SI covalent interactions of complexes. These structural modifications of particles had important effects on the chemical stability and gastrointestinal digestion fate of SI. The ultrasonic covalent complexation had a greater resistance to heat-induced chemical degradation of SI and improved its chemical stability. Furthermore, the 240 W ultrasonic covalent complexes showed lower protein digestibility during digestion, and provided stronger protection for SI, which improved the digestion stability and antioxidant activity. Therefore, appropriate ultrasound promoted SPI-SI interactions to improve the stability and functional properties of complexes, which provided a theoretical basis for the development of new complexes and their applications in functional foods.

Germination-induced modifications of starch structure, flour-processing characteristics, and in vitro digestive properties in maize.

Current research on maize germination suffers from long sampling intervals, and the relationship between the starch structure and the processing properties of flour in maize is still unclear. This study observed the effect of germination on the structure and composition of maize starch and the processing properties of maize flour over a 72 h period using a short interval sampling method. At 36 h, the short-range ordered structure, crystallinity, and enthalpy of starch reached the highest values of 1.02, 34.30%, and 9.90 J/g, respectively. At 72 h, the ratios of rapidly-digested starch (RDS) and slowly-digested starch (SDS) enhanced to 29.37% and 28.97%; the RS content reduced to 35.37%; and the flow properties of the starch were improved. This study enhances the understanding of the effects of germination on the processing properties of maize starch and flour, determines the appropriate application, and recommends the use of germination in the food industry.

Effect of Heat Treatment Combined with TG Enzyme Cross-Linking on the Zein-Pea Protein Complex: Physicochemical and Gel Properties.

Plant proteins have the advantages of low cost and high yield, but they are still not comparable to animal proteins in processing due to factors such as gelation and solubility. How to enhance the processing performance of plant proteins by simple and green modification means has become a hot research topic nowadays. Based on the above problems, we studied the effect of gel induction on its properties. In this study, a pea protein-zein complex was prepared by the pH cycle method, and the effects of different induced gel methods on the gel properties of the complex protein were studied. The conclusions are as follows: All three gel induction methods can make the complex protein form a gel system, among which the gel strength of heat treatment and the TG enzyme-inducted group is the highest (372.84 g). Through the observation of the gel microstructure, the gel double network structure disappears and the structure becomes denser, which leads to a stronger water-binding state of the gel sample in the collaborative treatment group. In the simulated digestion experiment, heat treatment and enzyme-induced samples showed the best slow-release effect. This study provides a new method for the preparation of multi-vegetable protein gels and lays a theoretical foundation for their application in food processing.

On the modification of plant proteins: Traditional methods and the Hofmeister effect.

With increasing consumer health awareness and demand from some vegans, plant proteins have received a lot of attention. Plant proteins have many advantages over animal proteins. However, the application of plant proteins is limited by a number of factors and there is a need to improve their functional properties to enable a wider range of applications. This paper describes the advantages and disadvantages of traditional methods of modifying plant proteins and the appropriate timing for their use, and collates and describes a method with fewer applications in the food industry: the Hofmeister effect. It is extremely simple but efficient in some respects compared to traditional methods. The paper provides theoretical guidance for the further development of plant protein-based food products and a reference value basis for improving the functional properties of proteins to enhance their applications in the food industry, pharmaceuticals and other fields.

Food-packaging applications and mechanism of polysaccharides and polyphenols in multicomponent protein complex system: A review.

With the increasingly mature research on protein-based multi-component systems at home and abroad, the current research on protein-based functional systems has also become a hot spot and focus in recent years. In the functional system, the types of functional factors and their interactions with other components are usually considered to be the subjective factors of the functional strength of the system. Because this process is accompanied by the transfer of protons and electrons in the system, it has antioxidant, antibacterial and anti-inflammatory properties. Polyphenols and polysaccharides have the advantages of wide source, excellent functionality and good compatibility with proteins, and have become excellent and representative functional factors. However, polyphenols and polysaccharides are usually accompanied by poor stability, poor solubility and low bioavailability when used as functional factors. Therefore, the effect of separate release and delivery will inevitably lead to non-significant or direct degradation. After forming a multi-component composite system with the protein, the functional factor will form a stable system driven by hydrogen bonds, hydrophobic forces and electrostatic forces between the functional factor and the protein. When used as a delivery system, it will protect the functional factor, and when released, through the specific recognition of the cell membrane receptor signal, the effect of fixed-point delivery is achieved. In addition, this multi-component composite system can also form a functional composite film by other means, which has a long-term significance for prolonging the shelf life of food and carrying out specific antibacterial.

[Treatment of irreducible intertrochanteric femoral fracture in elderly by folding top technique combined with right-angle pliers prying and pulling under G-arm X-ray fluoroscopy].

Objective: To explore the effectiveness of irreducible intertrochanteric femoral fracture in the elderly by treating with folding top technique and right-angle pliers prying and pulling under G-arm X-ray fluoroscopy. Methods: The clinical data of 74 elderly patients with irreducible intertrochanteric femoral fracture admitted between February 2016 and December 2022 and met the selection criteria were retrospectively analyzed. Among them, 38 cases were treated with folding top technique combined with right-angle pliers prying and pulling under G-arm X-ray fluoroscopy and intramedullary nailing fixation (study group), and 36 cases were treated with limited open reduction combined with other reduction methods and intramedullary nailing fixation (control group). There was no significant difference in baseline data between the two groups, such as age, gender, cause of injury, affected side and classification of fractures, complicated medical diseases, and time from injury to operation ( P>0.05). The operation time, intraoperative blood loss, hospital stay, fracture reduction time, fracture healing time, and complications of the two groups were recorded and compared. The quality of fracture reduction was evaluated by Baumgaertner et al. and Chang et al. fracture reduction standards. Results: Patients in both groups were followed up 10-14 months, with an average of 12 months. The operation time and intraoperative blood loss in the study group were significantly less than those in the control group ( P<0.05), there was no significant difference in hospital stay between the two groups ( P>0.05). At 2 days after operation, according to the fracture reduction standards of Baumgaertner et al. and CHANG Shimin et al., the quality of fracture reduction in the study group was better than that in the control group, and the fracture reduction time in the study group was shorter than that in the control group, with significant differences ( P<0.05). After operation, the fractures of the two groups all healed, and there was no significant difference in healing time between the two groups ( P>0.05). During the follow-up, there was no complication such as incision infection, internal fixation failure, deep venous thrombosis of lower limbs, intramedullary nail breakage, spiral blade cutting, or hip varus in the two groups, except for 2 cases of coxa vara in the control group. Conclusion: For the irreducible intertrochanteric femoral fracture, using folding top technique combined with right-angle pliers prying and pulling under G-arm X-ray fluoroscopy can obviously shorten the operation time, reduce the intraoperative blood loss, and improve the quality of fracture reduction.

Postharvest ripening of newly harvested corn: Weakened interactions between starch and protein.

The effects of postharvest ripening of corn on the mechanisms of starch and protein interactions were investigated using molecular dynamics and several chemical substances. Sodium dodecyl sulfate (SDS) treatment all significantly affected the starch content, molecular weight of proteins, relative crystallinity, pasting characteristics and dynamic viscoelasticity in samples before and after postharvest ripening. In the corn that had not undergone postharvest ripening, there were also significant electrostatic interactions and hydrogen bonds between starch and protein. In addition, molecular dynamics had demonstrated that the forces between starch and protein in corn were mainly hydrophobic interactions, electrostatic interaction, and hydrogen bonds. Compared with zein, corn glutelin was more tightly bound to starch. The binding energy of starch to both proteins was reduced in after postharvest-ripened corn. This study laid a rationale for investigating the change mechanism of corn postharvest ripening quality and improving processing property and edible quality of corn.

Research progress of protein complex systems and their application in food: A review.

Among the common natural biomolecules, the excellent properties of proteins have attracted extensive attention from researchers for functional applications, however, in native form proteins have many limitations in the performance of their functional attribute. However, with the deepening of research, it has been found that the combination of natural active substances such as polyphenols, polysaccharides, etc. with protein molecules will make the composite system have stronger functional properties, while the utilization of pH-driven method, ultrasonic treatment, heat treatment, etc. not only provides a guarantee for the overall protein-based composite system, but also gives more possibilities to the protein-composite system. Protein composite systems are emerging in the fields of novel active packaging, functional factor delivery systems and gel systems with high medical value. The products of these protein composite systems usually have high functional properties, mainly due to the interaction of the remaining natural active substances with protein molecules, which can be broadly categorized into covalent interactions and non-covalent interactions, and which, despite the differences in these interactions, together constitute the cornerstone for the stability of protein composite systems and for in-depth research.

Ginseng Glucosyl Oleanolate from Ginsenoside Ro, Exhibited Anti-Liver Cancer Activities via MAPKs and Gut Microbiota In Vitro/Vivo.

Ginseng is widely recognized for its diverse health benefits and serves as a functional food ingredient with global popularity. Ginsenosides with a broad range of pharmacological effects are the most crucial active ingredients in ginseng. This study aimed to derive ginseng glucosyl oleanolate (GGO) from ginsenoside Ro through enzymatic conversion and evaluate its impact on liver cancer in vitro and in vivo. GGO exhibited concentration-dependent HepG2 cell death and markedly inhibited cell proliferation via the MAPK signaling pathway. It also attenuated tumor growth in immunocompromised mice undergoing heterograft transplantation. Furthermore, GGO intervention caused a modulation of gut microbiota composition by specific bacterial populations, including Lactobacillus, Bacteroides, Clostridium, Enterococcus, etc., and ameliorated SCFA metabolism and colonic inflammation. These findings offer promising evidence for the potential use of GGO as a natural functional food ingredient in the prevention and treatment of cancer.

Riboflavin-loaded soy protein isolate cold gel treated with combination of high intensity ultrasound and high hydrostatic pressure: Gel structure, physicochemical properties and gastrointestinal digestion fate.

Transglutaminase (TGase) was added to soy protein isolate (SPI) dispersion after the combination treatment of high intensity ultrasound (HIU) and high hydrostatic pressure (HHP) to catalyze the formation of cold gel, which was used to encapsulate riboflavin. The structure, physicochemical properties and in vitro digestion characteristics of riboflavin-loaded SPI cold gel were investigated. HIU-HHP combined treatment enhanced the strength, water retention, elastic property, thermal stability and protein denaturation degree of riboflavin-loaded SPI cold gels, and improved the gel network structure, resulting in a higher encapsulation efficiency of riboflavin and its chemical stability under heat and light treatment. HIU-HHP combined treatment reduced the erosion and swelling of SPI cold gel in simulated gastrointestinal fluid, and improved the sustained release effect of SPI gel on riboflavin by changing the digestion mode and rate of gel. In addition, HIU-HHP combined treated gels promoted the directional release of riboflavin in the simulated intestinal fluid, thereby improving its bioaccessibility, which was related to the secondary structure orderliness, tertiary conformation tightness and aggregation degree of protein during the gastrointestinal digestion. Therefore, HIU-HHP combined treatment technology had potential application value in improving the protection, sustained/controlled release and delivery of SPI cold gels for sensitive bioactive compounds.

Effect of Microwave Intermittent Drying on the Structural and Functional Properties of Zein in Corn Kernels.

Microwave intermittent drying was carried out on newly harvested corn kernels to study the effects of different microwave intermittent powers (900 W, 1800 W, 2700 W, and 3600 W) on the structural and functional properties of zein in corn kernels. The results showed that microwave drying could increase the thermal stability of zein in corn kernels. The solubility, emulsification activity index, and surface hydrophobicity increased under 1800 W drying power, which was due to the unfolding of the molecular structure caused by the increase in the content of irregular structure and the decrease in the value of particle size. At a drying power of 2700 W, there was a significant increase in grain size values and ß-sheet structure. This proves that at this time, the corn proteins in the kernels were subjected to the thermal effect generated by the higher microwave power, which simultaneously caused cross-linking and aggregation within the proteins to form molecular aggregates. The solubility, surface hydrophobicity, and other functional properties were reduced, while the emulsification stability was enhanced by the aggregates. The results of the study can provide a reference for the in-depth study of intermittent corn microwave drying on a wide range of applications of zein in corn kernels.

Research on corn starch and black bean protein isolate interactions during gelatinization and their effects on physicochemical properties of the blends.

The interaction between starch and protein during food processing is crucial for controlling food quality. This study aims to understand the interactions between corn starch and black bean protein isolate (BBPI) at various gelatinization phases and their effects on the physicochemical properties of the blends. BBPI reduced the rheological properties of the corn starch/BBPI mixed system during gelatinization, increasing light transmittance and gelatinization temperature, while decreasing total viscosity and enthalpy change. The changes in starch and protein microstructure during gelatinization indicated that BBPI adhered to the starch particle surface or partially penetrated the swollen starch particles. Fourier transform infrared spectroscopy (FT-IR) revealed that BBPI decreased the number of hydrogen bonds within starch, with no newly formed functional groups in the mixed system. Furthermore, BBPI reduced the composite relative crystallinity (RC). The effect of protein addition on water migration in the mixed system demonstrates that protein and starch compete for water during gelatinization, preventing water molecules from diffusing into starch particles.

Transglutaminase-induced soybean protein isolate cold-set gels treated with combination of ultrasound and high pressure: Physicochemical properties and structural characterization.

Soybean protein isolate (SPI) was treated by the combined exposure to ultrasound and high pressure and then subjected to transglutaminase (TGase)-catalyzed cross-linking to prepare SPI cold-set gels. The effects of combined treatments on physicochemical and structural properties of TGase-induced SPI cold-set gels were investigated. The combination of ultrasound and high pressure promoted the covalent disulfide bonds and ε-(γ-glutaminyl) lysine isopeptide bonds as well as non-covalent hydrophobic interactions, which further improved the gelation properties of SPI compared to ultrasound or high pressure alone. In particular, the 480 W ultrasound followed by high pressure treatment of gels led to higher strength (120.53 g), water holding capacity (95.39 %), immobilized water (93.92 %), lightness (42.18), whiteness (51.03), and elasticity (G' = 407 Pa), as well as more uniform and compact microstructure, thus resulting in the improved gel network structure. The combination of two treatments produced more flexible secondary structure, tighter tertiary conformation and higher denaturation degree of protein in the gels, leading to more stable gel structure. The structural modifications of SPI contributed to the improvement of its gelation properties. Therefore, the combined application of ultrasound and high pressure can be an effective method for improving the structure and properties of TGase-induced SPI cold-set gels.

Maleic anhydride-modified xylanase and its application to the clarification of fruits juices.

At presently, the catalytic activity of xylanase is sub-optimal, and the required reaction conditions are harsh. To improve its catalytic activity and stability, xylanase (XY) was chemically modified with maleic anhydride (MA). The enzymatic properties of this maleic anhydride-modified xylanase (MA-XY) were then evaluated and analyzed spectroscopically. The results showed that the thermal stability, use of organic solvents, storage stability and the pH range of 3.0 to 9.0 for MA-XY were better than that for XY alone. The kinetic parameters of the enzyme (Km values) decreased from 40.63 to 30.23 mg/mL. Spectroscopic analysis showed that XY had been modified by the acylation reaction to become a tertiary structure. An assay based on clarifying fruit juices showed that the clarification capacity and reducing sugar content using MA-XY increased compared with those using XY. Overall, this study provides a theoretical basis for improving the application of XY in the food industry.

Targeted metabolic reveals different part of maize in polyphenolic metabolites during germination and hypoglycemic activity analysis.

In this study, qualitative and quantitative analyses of phenolic compounds in the maize germinating seed embryo, radicle, and germ were performed at 0, 48, and 96 h post-germination, followed by the evaluation of their hypoglycemic activity. The results revealed the accumulation of 80 phenolics in different parts of germinated maize, of which 47, 48, and 53 were present in the seed embryo, radicle, and germ. After germination 22, 26, and 34 polyphenols were found to differential accumulate in the seed embryo, radicle, and germ. At 96 h post-germination, the content of monomeric phenols in the germ was higher than that in the radicle and seed embryo. Moreover, the inhibitory activity of polyphenols in the germ towards α-glucosidase and α-amylase was higher than that in the radicle and seed embryo. These results indicate that germination can effectively improve the type and content of phenolic compounds in different parts of maize.

Ginsenoside Rk1 inhibits HeLa cell proliferation through an endoplasmic reticulum signaling pathway.

Background: Changes to work-life balance has increased the incidence of cervical cancer among younger people. A minor ginseng saponin known as ginsenoside Rk1 can inhibit the growth and survival of human cancer cells; however, whether ginsenoside Rk1 inhibits HeLa cell proliferation is unknown. Methods and results: Ginsenoside Rk1 blocked HeLa cells in the G0/G1 phase in a dose-dependent manner and inhibited cell division and proliferation. Ginsenoside Rk1 markedly also activated the apoptotic signaling pathway via caspase 3, PARP, and caspase 6. In addition, ginsenoside Rk1 increased LC3B protein expression, indicating the promotion of the autophagy signaling pathway. Protein processing in the endoplasmic reticulum signaling pathway was downregulated in Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, consistent with teal-time quantitative PCR and western blotting that showed YOD1, HSPA4L, DNAJC3, and HSP90AA1 expression levels were dramatically decreased in HeLa cells treated with ginsenoside Rk1, with YOD1 was the most significantly inhibited by ginsenoside Rk1 treatment. Conclusion: These findings indicate that the toxicity of ginsenoside Rk1 in HeLa cells can be explained by the inhibition of protein synthesis in the endoplasmic reticulum and enhanced apoptosis, with YOD1 acting as a potential target for cervical cancer treatment.

Mechanism of ultrasonic combined with different fields on protein complex system and its effect on its functional characteristics and application: A review.

In recent years, new food processing technologies (such as ultrasound, high-pressure homogenization, and pulsed electric fields) have gradually appeared in the public 's field of vision. These technologies have made outstanding contributions to changing the structure and function of protein complexes. As a relatively mature physical field, ultrasound has been widely used in food-related fields. However, with the gradual deepening of related research, it is found that the combination of different fields often makes some characteristics of the product better than the product under the action of a single field, which will not only lead to a broader application prospect of the product, but also make the product a better solution in some special fields. There are usually synergistic and antagonistic effects when multiple fields are combined, and these effects will also gradually enlarge the interaction between different components of the protein complex system. In this paper, while explaining the mechanism of ultrasonic combined with other fields affecting the steric hindrance and shielding site of protein complex system, we will further explain the effect of this effect on the function and application of protein complex system.

Advances in aptamers, and application of mycotoxins detection: A review.

Mycotoxin contamination in food products can easily cause serious health hazards and economic losses to human beings. How to accurately detect and effectively control mycotoxin contamination has become a global concern. Mycotoxins conventional detection techniques e.g; ELISA, HPLC, have limitations like, low sensitivity, high cost and time-consuming. Aptamer-based biosensing technology has the advantages of high sensitivity, high specificity, wide linear range, high feasibility, and non-destructiveness, which overcomes the shortcomings of conventional analysis techniques. This review summarizes the sequences of mycotoxin aptamers that have been reported so far. Based on the application of four classic POST-SELEX strategies, it also discusses the bioinformatics-assisted POST-SELEX technology in obtaining optimal aptamers. Furthermore, trends in the study of aptamer sequences and their binding mechanisms to targets is also discussed. The latest examples of aptasensor detection of mycotoxins are classified and summarized in detail. Newly developed dual-signal detection, dual-channel detection, multi-target detection and some types of single-signal detection combined with unique strategies or novel materials in recent years are focused. Finally, the challenges and prospects of aptamer sensors in the detection of mycotoxins are discussed. The development of aptamer biosensing technology provides a new approach with multiple advantages for on-site detection of mycotoxins. Although aptamer biosensing shows great development potential, still some challenges and difficulties are there in practical applications. Future research need high focus on the practical applications of aptasensors and the development of convenient and highly automated aptamers. This may lead to the transition of aptamer biosensing technology from laboratory to commercialization.

Thermodynamics and Physicochemical Properties of Immobilized Maleic Anhydride-Modified Xylanase and Its Application in the Extraction of Oligosaccharides from Wheat Bran.

Xylanases are the preferred enzymes for the extracting of oligosaccharides from wheat bran. However, free xylanases have poor stability and are difficult to reuse, which limit their industrial application. In the present study, we covalently immobilized free maleic anhydride-modified xylanase (FMA-XY) to improve its reusability and stability. The immobilized maleic anhydride-modified xylanase (IMA-XY) exhibited better stability compared with the free enzyme. After six repeated uses, 52.24% of the activity of the immobilized enzyme remained. The wheat bran oligosaccharides extracted using IMA-XY were mainly xylopentoses, xylohexoses, and xyloheptoses, which were the ß-configurational units and α-configurational units of xylose. The oligosaccharides also exhibited good antioxidant properties. The results indicated that FMA-XY can easily be recycled and can remain stable after immobilization; therefore, it has good prospects for future industrial applications.