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Polysaccharides are a class of natural macromolecular polymers with complex and large molecular structures, which are closely related to their biological activities. However, traditional analytical methods can only provide limited information on the structures of polysaccharides. Mass spectrometry (MS) is an analytical method that measures the mass-to-charge ratio of molecules allowing for determination of the mass and calculation of the the molecular structure. As a powerful tool for polysaccharide structure analysis, MS can provide rich information, including molecular mass, polymerization degree, monosaccharide composition, glycosidic bond type, the order of arrangement of glycosyl groups, and substituent group sites, which has unique advantages in the characterization of polysaccharide structure. This paper summarizes the general pattern of mass spectral fragmentation of polysaccharides, introduces the principles and characteristics of different types of MS as well as representative applications of MS combined with electron ionization source, fast atom bombardment source, electrospray ionization source, matrix-assisted laser desorption ion source, real-time direct analysis source, ion mobility or tandem mass spectrometry for the structural elucidation of polysaccharides. Furthermore, future prospects for the application of new MS techniques for analyzing the structures of polysaccharides are discussed. The aim of this paper is to summarize the application of MS to provide scientific reference for the basic research work of polysaccharide compounds, such as quality standard, structural characterization, pharmacodynamics, pharmacokinetic, constitutive relationship, and the development and creation of polysaccharide food, health food, and clinical drugs.

The long-standing fermented meat products were deeply popular with consumers due to the distinctive flavor and long storage life. From the point of protein degradation in the process of fermentation of meat products and based on the recent researches of fermented meat products, this paper discusses the factors affecting the muscle protein degradation including the function of microbial proteases and endogenous enzymes, and the protein hydrolysis activity of core microorganism. The structure changes of muscle protein during fermentation are analyzed, including secondary and tertiary structure and functional properties of protein. This paper furthermore summarizes how the muscle protein degradation during fermentation improving the texture properties and flavor of the fermented meat products, and deterioration of products due to excessive protein degradation. Finally, the perspectives of the future researches are listed in order to provide some meaningful ideas for the intensive study of the fermentation control of meat products.

Lipid is an important component except starch and protein in rice, which not only has unique nutritional value but also has a great impact on the functional properties of starch. In this paper, the species, structure, distribution, and content of lipids in rice were summarized, and the mechanism, structure characteristics and influencing factors of starch-lipid interaction were discussed. The interaction effects on the properties of starch, including swelling, gelatinization, rheology, retrogradation and digestive ability were reviewed. This paper provided useful information on understanding the interaction between starch and endogenous lipids in rice as well as its influence on the starch properties, which could promote the improvement of rice quality and the development of functional rice.

In this paper, wheat flour was irradiated at different doses (0, 5, 10, 15, 20 and 25 kGy) to investigate the effects of 60Co-γirradiation on the structural and functional properties of its gluten. The disulfide bond was broken by irradiation, and the content of the free sulfhydryl group increased. The results of Fourier infrared spectroscopy showed that the secondary structure of gluten protein was rearranged with decrease in a-helix content and an increase in β-sheet content. Raman spectroscopy and surface hydrophobicity showed that the microenvironment of aromatic amino acid side chains changed. Irradiation treatment resulted in the tryptophan and tyrosine residues tending more toward the exposed state, and the surface hydrophobicity increased. Meanwhile, irradiation increased the solubility, water and oil holding, and emulsifying properties of gluten proteins, and the maximum value reached at 15 kGy（solubility is 0.46 mg/mL, water holding 3.13 g/g, oil holding 4.33 g/g, emulsification 6.669 m2/g）. In conclusion, the proper dose of gamma-irradiation can change the secondary and tertiary structure of gluten, and improve its functional properties such as solubility, water retention and emulsification, which is conducive to expanding the application space of gluten protein and providing theoretical references for industrial applications.

In order to investigate the changes in structure and properties of waxy maize starch (WMS) after its nano-starch was prepared by pullulanase enzymolysis-dynamic high pressure micro-fluidization technology (P-DHPM), this paper explored the trends of changes in starch microstructure, crystalline structure, molecular structure, particle size, molecular weight, and thermal properties before and after the treatment. The results showed that spherical starch particles were turned into fragmentization, and the crystalline structures were transferred into amorphous states, the short-range ordered structure was increased, and the molecular weight of starch was decreased with the increment of enzymatic hydrolysis time. In the meantime, the peak gelatinization temperature (Tp) of treated starch was decreased from 71.23 ℃ to 55.81 ℃, and the enthalpy value of pasting (ΔH) was decreased to 4.68 J/g significantly (P

As people’s consumption levels and health awareness have risen, the consumer demand for functional foods is steadily increasing. Medium-chain fatty acids (MCFAs), an important class of dietary fatty acids, have been regarded as high-value functional foods due to their unique transportation system and the fact that they can be metabolized rapidly in the body while producing high energy. Beginning with an overview of the types and structures of MCFAs, this paper goes on to elaborate the metabolic pathway of MCFAs in the human body and then summarize recent research on MCFAs in the adjuvant treatment of different diseases. This article focuses on the positive role of MCFAs in the adjuvant treatment of Alzheimer’s disease, epilepsy, cancer, diabetes, obesity, and other diseases, and expounds their action mechanism. Finally, an outlook on the future development of MCFAs is given. Overall, this review provides a theoretical basis for promoting the application of MCFAs in the fields of food and medicine.

Mesona is a special edible and medicinal food in China. The country has an abundant Mesona output and a large number of Mesona consumers. Polysaccharide is one of the important active components in Mesona, which has a variety of biological activities in disease prevention and treatment. Currently, Mesona polysaccharide has been widely used in Chinese Traditional medicine, herbal tea, as well as jelly. However, there are problems such as insufficient development of deep-processing products. In this paper, the domestic and foreign literature in the past recent years are retrieved and collected. This article comprehensively proposes the extraction, isolation and purification technologies of Mesona polysaccharide, as well as their characteristic structures, and rheological and gelling properties. Additionally, their functional activities and the underlying mechanism of action on antioxidant, regulation of gut flora, anti-hyperglycemia, anti-hyperlipidemia, liver protection and immunoregulation are systematically reviewed. This review provides useful ideas and guidance for the basic research as well as the commercialization of research on Mesona.

Schisandra chinensis refers to the dried mature fruit of the plant Schisandra chinensis (Turcz.) Baill from the Magnoliaceae family, or Schisandra sphenanchera Rehd. etWils. It is rich in various active components such as polysaccharides, lignans, volatile oils, and polyphenols. Polysaccharides, as its main active ingredients, are extracted by biphasic extraction, enzymatic method, ultrasonic method, microwave method, ultrasonic-microwave synergy, microwave-enzymatic synergy, and aqueous extraction, among which biphasic extraction has the highest efficiency, and ultrasonic and aqueous extraction are the most widely used methods. Schisandra chinensis polysaccharides are mainly composed of rhamnose, mannose, glucose, galactose, arabinose and galacturonic acid, and the average molecular weight roughly ranges from 103~105 Da. Modern pharmacological studies have shown that Schisandra chinensis polysaccharides have significant antioxidant, immunomodulatory, antitumor, hepatoprotective, hypoglycemic and lipid-lowering efficacy, and they are of significant significance for the development of high-value in the field of food and medicine. Therefore, this paper systematically summarizes the extraction process, structural characteristics and biological activities of Schisandra chinensis polysaccharides and their related mechanisms at home and abroad in recent years, and looks forward to its research direction and application prospects, with a view to providing reference for the in-depth research and application development of Schisandra chinensis.

Alginate is one of the most abundant marine polysaccharides, which can be degraded into alginate oligosaccharides (AOS) by chemical, physical and biological methods. AOS, linear oligosaccharide composed of guluronic acid and mannuronic acid, have a variety of biological activities such as antimicrobial, anti-inflammatory, and immunoregulatory activities, and these biological activities are closely related to their structural diversity. AOS prepared by different degradation methods have different uronic acid compositions, polymerization degrees and special structures. Therefore, exploring the structure-function relationship of AOS will help to fully understand the activity of AOS and improve its application value. In this paper, the reaction mechanisms of the various methods to prepare AOS, the structures of the resulting products, and the structure-function relationship of AOS are reviewed in order to provide a reference for further research and application of AOS.

Oil bodies (OB) are subcellular organelles that store lipids in plant seeds, which are composed of neutral triacylglycerol (TAG), a monolayer of polar phospholipids surrounding TAG, and proteins embedded in the phospholipid membrane. The composition and unique structure of OB make it have good oxidation stability. OB can be extracted by water extraction and enzyme-assisted extraction. As a natural pre-emulsified oil-in-water emulsion, OB emulsions have been gradually used to replace synthetic oil droplets and are promising for broad applications in the fields of food, medicine and animal husbandry. Therefore, it is of practical significance to explore the effects of OB composition and structure as well as environmental factors on the oxidation stability of OB emulsions. In this paper, the composition, structure and extraction process of OB, the oxidation stability of OB emulsions and future prospects for its application in the food field are reviewed, which can provide a reference for the development and utilization of OB.

To obtain lily polysaccharides efficiently and characterize the structure of polysaccharides, the polysaccharides from lily was extracted by using microwave-assisted aqueous two-phase extraction in this paper. The best extraction process was determined by single factor experiment and orthogonal experiment. The crude extract of lily polysaccharides was purified via DEAE-52 and Sephadex G-100 column chromatography in turn to obtain a single fraction (LP2-SG). The molecular weight and monosaccharide composition of LP2-SG were determined by high performance gel permeation chromatography and gas chromatography, respectively, and then its structure was preliminarily characterized. The results showed that the optimum extracting parameters to achieve the highest yield of polysaccharides 10.15%±0.11% from lily by microwave-assisted aqueous two-phase extraction was obtained under the microwave power of 400 W, ammonium sulfate mass fraction of 20%, ethanol volume fraction of 50%, and solid-to-liquid ratio of 1:30 g/mL. LP2-SG with a molecular weight of 530.51 kDa was composed of mannose, glucose, and galactose with a molar ratio of 11.63:29.85:8.46. LP2-SG has no characteristic absorption at 260 nm and 280 nm, and it had typical infrared absorption characteristics of polysaccharides. The results of this study provide an important reference for the efficient extraction and deep development of lily polysaccharides.

As an environmental-friendly renewable polymer material, nanocellulose (NCC) has great application potential and ecological benefits. In this paper, we introduce the structural properties and preparation techniques of NCC, give an overview of the methods used to characterize and modify NCC, and elaborate on the latest advances in the application of food industry. Additionally, we use bibliometrics to analyze and summarize the research hotspots in the NCC field. It is expected that the green and efficient production of NCC and the development of functional composites for different purposes will be research priorities in the future.

A variety of phenolic and non-phenolic substrates can be oxidized by laccase using molecular oxygen as an auxiliary substrate. Due to the fact that laccase produces only water as a by-product, laccase is considered a "green tool enzyme" because it is environmentally friendly. Among the many industries in which laccase is used are sewage treatment, paper making, textiles, food, organic synthesis, biopharmaceuticals, detection, and ecological restoration. Compared to fungal laccase, prokaryotic laccase tends to have the following advantages: higher thermal stability and higher optimum reaction temperature, better suited to catalyse reactions under alkaline conditions, less sensitive and less dependent on inhibitors and metal ions, and more amenable to heterologous expression and protein engineering transformation. As a result, prokaryotic laccase has gained increasing attention in recent years. It describes in detail the origins, structure, catalytic process and physicochemical properties of prokaryotic laccase, its applications, and the recent research progress in this area over the past few years.

The resistance to melting is an important indicator of the quality of ice cream. During transport, storage and distribution, poorly melting resistance ice cream will inevitably become deformed due to fluctuations in ambient temperature, which in turn will affect the consumer experience, product sales and even the brand's reputation. Stabilisers are crucial to the melting resistance of ice cream. This paper reviews the mechanisms of stabilisers on ice cream melting resistance, the properties of different anionic/non-ionic stabilisers and their mechanism of actionon ice cream resistance, mainly in terms of gel formation, inhibition of ice crystal growth and enhancement of ice cream serum phase viscosity. Furtherly, it provides theoretical guidance for the development of cultural and creative ice cream, ice cream with complex structure and ice cream circulation.

Wheat bran is a by-product of wheat processing, which contains many nutrients, such as protein, vitamins, dietary fiber, phenols and polysaccharides. Studies have shown that wheat bran polysaccharide can prevent diabetes, lower blood sugar, improve immunity, anti-tumor and other effect. It has broad development prospects in daily necessities, health food and medical supplies. Different extraction and purification methods of wheat bran polysaccharides will cause differences in the structure of wheat bran polysaccharides, but the structure affects its biological activity. Therefore, it is of great significance to explore the structural characteristics of wheat bran polysaccharide to reveal its biological activity. In this paper, the extraction method, separation and purification, structure characterization and physiological function of wheat bran polysaccharide in recent years are described. At the same time, the structure-activity relationship between the structure of wheat bran polysaccharide and its biological activities is discussed. The present problems and application prospect of wheat bran polysaccharide are prospected in order to provide theoretical basis and new ideas for the utilization and research of wheat bran polysaccharide in health care and medicine.

Resistant starches are polysaccharides that are not digested and absorbed in the small intestine of healthy humans and are beneficial to human health. Regenerated starch (RS3), as one of the types of resistant starch, is widely used in the food industry because of its good thermal stability and low water-holding capacity. This paper reviews the factors affecting the preparation of RS3 resistant starch by ultrasonic, microwave, moist heat, and toughening on its yield, physicochemical properties, and structure of RS3 resistant starch in recent years, and provides an outlook on the current status of physical preparation of RS3 resistant starch, to provide useful references for the study of physical preparation of RS3 resistant starch and promote the practical application of physical preparation of resistant starch.

As an important nutrient in milk, fat exists in the form of milk fat globules. Cow’s milk is an important substitute for breast milk, but the difference between its milk fat globules and those of human milk remains to be clarified. In this paper, the main differences in protein composition, lipid composition, structure and function between cow’s and human milk fat globules are reviewed. The types of milk fat globule membrane proteins (MFGMPs) in human milk are significantly more than those in cow’s milk, and there are also obvious differences in the abundance of some special proteins. The composition and distribution of unsaturated and saturated fatty acids in cow’s milk and human milk are also different. Sphingomyelin is more abundant in human milk phospholipids, but in cow’s milk, lecithin is the main phospholipid. In all mammalian milk, the core of the lipid structure is triglyceride, encapsulated by a complex three-layer membrane. In terms of composition and structure, there is heterogeneity in milk fat globule membrane (MFGM) between the same species and different species. By summarizing the differences between human milk and cow’s milk fat globules, this review aims to increase the utilization rate and value of milk MFGM, to improve the structure of simulated milk fat globules, and to further optimize infant formula.

Capsaicinoids are a class of alkaloids with vanillyl and medium/long-chain fatty acid amide structures, and capsaicin and dihydrocapsaicin are the most pungent capsaicinoids. Some capsaicinoids activate related receptors and induce the transmission of nociceptive and thermic neural signals, leading to pungency perception. The Scoville scale is the most common method for pungency evaluation. However, it cannot reflect the actual pungency of samples because the result is only correlated with the contents of pungent substances. Time-intensity approach provides several quantitative indexes to measure pungency and is more useful. In addition to increasing the content of capsaicinoids, using aqueous-based carrier, increasing the temperature, sensitization, and some sensory stimuli can enhance the pungency perception of capsaicinoids, which deserves special attention in sensory evaluation. In summary, this paper reviewed the structure and distribution of capsaicinoids, mechanism and evaluation methods for pungency perception, as well as factors that may influence the perception of spiciness. This article provides some reference for the pungency prediction and development of spicy foods.

Poria cocos, an important edible and medicinal material, has obvious diuretic, spleen-enhancing and tranquilizing functions. Polysaccharides are one of the most important bioactive ingredients in P. cocos. Polysaccharides from P. cocos have a variety of bioactivities, indicating their great potential in the fields of food, medicine and nutraceutical. In this paper, the structure, bioactivity, mechanism of action and structure-bioactivity relationships of P. cocos polysaccharides are systematically summarized, which will provide a basis for further development of P. cocos polysaccharides.

In this paper, gelatin-based blend films integrated with zein nanoparticles loaded with Litsea cubeba oil were prepared by solution casting using gelatin, zein and Litsea cubeba oil as film-forming substrates. The effects of nanoparticles incorporation on the opacity, microstructure, thermal stability, mechanical properties, hydrophobicity, antibacterial and antioxidant properties of the blend films were investigated. The results showed that there was hydrogen bonds interaction and good compatibility between nanoparticles and gelatin. With increasing nanoparticles addition, the transparency of the blend films decreased significantly, and their hydrophobicity and antioxidant property were significantly improved (P

In this paper, mung bean protein was prepared by high moisture extrusion technology at different extrusion temperatures. The structure of the protein was analyzed by Fourier transform infrared spectroscopy, internal fluorescence spectroscopy, SDS-PAGE gel electrophoresis, and scanning electron microscopy. The results showed that the content of ionic bond, hydrophobic interaction, and disulfide bond increased first and then decreased, and the content of free thiol decreased first and then increased, after high-moisture extrusion. The content of β-sheet in the secondary structure of protein decreased significantly (P

Natural plant-derived dietary fiber (DF) is rich and has important physiological functions for human health. As the main active component of DF, the content of SDF is related to the quality of DF. Due to the low content of SDF and poor physical properties of natural plant DF, DF can not be fully utilized, which restricts the development and application of DF-related functional products. Therefore, it is urgent to use processing technology to treat DF to increase the content of SDF and improve the physicochemical and structural characteristics of DF. Ultrasonic technology, as an efficient and environmentally friendly modern food processing method, can change the structure of the material, improve yield of DF in raw material, and promote the dissolution of active ingredients by cavitation and mechanical effects. The ultrasonic technology is an effective method to improve the processing and functional characteristics of products, which is widely used in the preparation and modification of DF. This paper mainly reviews the improvement of SDF content in DF by ultrasonic technology, and focuses on the effect of ultrasonic technology on the structural characteristics, hydration characteristics, adsorption characteristics and viscosity of DF. Finally, the problems existing in the existing research are analyzed and summarized, and the future research trends are prospected to provide theoretical basis for the in-depth development and application of DF.

Konjac glucomannan (KGM) is a water-soluble natural plant polysaccharide from Konjac tubers, a special resource in China. It has good water absorption and thickening properties. Due to the complex structure, large molecular weight, and strong hydrophilicity of the characteristic acetyl group, KGM-based materials have poor moisture barrier properties and poor mechanical properties, further limiting their applications. In the early stage, it was found that the rigidity and flexibility of Konjac glucomannan particle molecular chain may affect the mechanical stability of its grain state. This strange molecular rigidity and flexibility may be due to the dynamic change of molecular chain to form stable KGM particles. It is speculated that the change of molecular rigid and flexible structure can improve the stability of molecular chain of KGM particles and obtain KGM particles with good mechanical properties. This paper will deeply analyze the research process of "KGM particle molecular rigidity and flexible structure → effect of molecular rigidity and flexible structure on KGM particle mechanical stability → molecular dynamics simulation interactive visual analysis → experimental verification and model evaluation → strengthening the mechanical properties of KGM based materials". The mechanical stability mechanism of Konjac glucomannan particle state structure formation and its molecular rigidity and flexible regulation behavior were revealed. The dynamic regulation was carried out by computer simulation to explore the relationship between them. The purpose is to reveal the mechanical stability mechanism of Konjac glucomannan particle state and lay a theoretical foundation for the bottleneck problem faced by Konjac refined powder in the processing process and its molecular stiffness and flexibility regulation.

This paper aimed to explore the changes in sesame phenolics and antioxidant activity and the correlation between the two after simulating in vitro digestion of sesame treated with ultra-high static pressure and different pressures, and observe the microstructure changes of sesame with rheometer and scanning electron microscope. The results showed that the contents of sesame lignans, total phenols and total flavonoids after different pressure treatments were significantly higher than those of untreated ones. The total lignans, total phenols and antioxidant activity composite index (ACI) of 200 MPa treated sesame samples were (30.20±1.20) mg/100 g, (473.04±13.73) µmol Rutin/100 g and (88.02±3.80) µmol Rutin/100 g, which were significantly higher than the untreated value. Regardless of the content of phenolic substances and the strength of antioxidant capacity, 200 MPa was an ideal treatment condition. The rheological characteristic curve showed that the viscosity was maximum when the pressure was 600 MPa, and the sesame structure became more stable. It was observed by scanning electron microscope that with the pressure change, the surface of the sample became loose and porous, and at the same time, it promoted the action of digestive enzymes, which was beneficial to improve the digestibility.

In this paper, the fine bran processed by heating and pressuring was added into the flour for the steamed bread. The moisture, TPA, water distribution and so on of steamed bread was evaluated during the storage in cool. The results showed that there was a certain correlation between the dosage of the fine bran and the water absorption of the flour, the regression equation is y=32.525*x+44.207, R2=0.996 9. The additive of the fine bran led to an increase of water content of steamed bread. The water migration of the steam bread weakened in cold storage, with the strong and weak binding water of steamed bread increased.The hardness and adhesion of the steamed bread strengthened, the reactivity and adhesion decreased for the addition of fine bran. Moreover, the yield value of steamed bread increased with the increase of bran content.