The Relationship between Preparation and Biological Activities of Animal-Derived Polysaccharides: A Comprehensive Review.

Polysaccharides are biomolecules found in microorganisms, plants, and animals that constitute living organisms. Glycosaminoglycans, unique acidic polysaccharides in animal connective tissue, are often combined with proteins in the form of covalent bonds due to their potent biological activity, low toxicity, and minimal side effects, which have the potential to be utilized as nutrition healthcare and dietary supplements. Existing studies have demonstrated that the bioactivity of polysaccharides is closely dependent on their structure and chain conformation. The characteristic functional groups and primary structure directly determine the strength of activity. However, the relationship between structure and function is still unclear, and the target and mechanism of action are not fully understood, resulting in limited clinical applications. As a result, the clinical applications of these polysaccharides are currently limited. This review provides a comprehensive summary of the extraction methods, structures, and biological activities of animal-derived polysaccharides that have been discovered so far. The aim is to promote developments in animal active polysaccharide science and provide theoretical support for exploring other unknown natural products.

Development and characterization of hydrogel-in-oleogel (bigel) systems and their application as a butter replacer for bread making.

BACKGROUND: Butter has been widely used in bakery products and it contains high level of saturated fats. However, excessive consumption of saturated fats would increase the risk of chronic disease. This study was to fabricate water-in-oil (W/O) type bigels as butter replacers to improve the quality attributes of breads. RESULTS: A stable water-in-oil (W/O) type bigel system was fabricated based on mixed oleogelators (rice bran wax and glycerol monostearate) and sodium alginate hydrogel. The ratios of oleogel to hydrogel could significantly affect the stability, microstructure and rheological properties of bigels. All of the bigels exhibited solid-like properties, with increased oleogel fractions, and the network structure of bigel became more compact and orderly with smaller sodium alginate gel particles. Meanwhile, the viscoelastic modulus and firmness of bigel increased, contributing to a higher stability. The bigel dough exhibited lower gel strength and relatively higher extensibility compared to the butter dough. Regardless of oleogel fractions, all the bigel produced bread with a higher specific volume and softer texture than the butter bread. When the oleogel fractions was less than 80%, increasing the oleogel fractions was more beneficial for improving the specific volume, softness and fluffy structure of bread. CONCLUSION: W/O type bigel as butter replacers showed great potential in improving the appearance, structure and textural properties of bread. © 2023 Society of Chemical Industry.

Flaxseed Gum/Arabic Gum/Tween 80-Based Oleogel as a Fat Substitute Applied in Emulsified Sausage: Physicochemical Properties, Sensory Attributes and Nutritional Quality.

In the present study, flaxseed gum (FG), Arabic gum (GA) and Tween 80 were used to prepare oleogels through an emulsion-templated method, and the obtained oleogels were designed for the partial substitution of pork fat in emulsified sausage. An increment in FG concentrations enhanced the viscoelasticity of emulsions, which resulted in the improved stability of emulsion systems, with smaller droplet sizes. In addition, increased FG concentrations contributed to higher mechanical strength, denser network structure and lower oil loss of oleogels. As a fat substitute, the prepared oleogels improved the textural properties and nutritional quality of emulsified sausages. With the increase in the substitution level of oleogels, the hardness and chewiness of the emulsified sausage increased, and the cooking loss decreased. Meanwhile, the reformulation with oleogels decreased the saturated fat from 57.04 g/100 g lipid to 12.05 g/100 g lipid, while increasing the ratio of omega-6 to omega-3 essential fatty acids from 0.10 to 0.39. The obtained results demonstrated that the flaxseed gum/Arabic gum/Tween 80-based oleogels had huge potential to successfully replace pork fat in emulsified sausage products.

Co-encapsulation of collagen peptide and astaxanthin in WG/OG/W double emulsions-filled alginate hydrogel beads: Fabrication, characterization and digestion behaviors.

The double emulsions-filled hydrogel beads delivery systems with controlled lipolysis and sustained-release property of co-encapsulated bioactive substances will be highly desired. Herein, the water-in-oil-in-water emulsion with gelled inner water phase and oil phase (WG/OG/W) filled hydrogel beads as a novel co-delivery system were developed with varied concentrations of rice bran wax and W/O emulsions to achieve effectively controlled release of lipolysis and nutraceuticals. Interestingly, the gelation of oil phase triggered by rice bran wax could enhance the storage stability of WG/OG/W emulsions due to the enhanced viscoelastic property. Increasing the mass fractions of W/O emulsions improved the stability of double emulsions due to increased viscosity and decreased particle size. Cryo-SEM observation showed that the double emulsion droplets were scattered in the three-dimensional network of alginate gel beads. Increased the addition of rice bran wax or W/O emulsions, the encapsulation efficiency of collagen peptide and astaxanthin was significantly improved. The in vitro digestion results indicated that increasing the concentrations of rice bran wax and W/O emulsion fractions in WG/OG/W emulsion-filled gel beads could effectively delay the release extent of free fatty acids and encapsulated nutraceuticals. The presence of rice bran wax contributed to increase the bioaccessibility of collagen peptide and astaxanthin.

Sodium alginate-sodium hyaluronate-hydrolyzed silk for microencapsulation and sustained release of kidney tea saponin: The regulation of human intestinal flora in vitro.

Kidney tea saponin (KTS) exhibits considerable efficacy in lowering glucose levels; however, it does not have widespread applications owing to its low intestinal utilization. Therefore, in the present study, we prepared sodium alginate (SA)/sodium hyaluronate (HA)/hydrolyzed silk (SF) gel beads for the effective encapsulation and targeted intestinal release of KTS. The gel beads exhibited an encapsulation rate of 90.67 % ± 0.27 % and a loading capacity of 3.11 ± 0.21 mg/mL; furthermore, the release rate of KTS was 95.46 % ± 0.02 % after 8 h of simulated digestion. Fourier transform infrared spectroscopy revealed that the hydroxyl in SA/HA/SF-KTS was shifted toward the strong peak; this was related to KTS encapsulation. Furthermore, scanning electron microscopy revealed that the gel bead space network facilitates KTS encapsulation. In addition, the ability of KTS and the gel beads to inhibit α-amylase (IC50 = 0.93 and 1.37 mg/mL, respectively) and α-glucosidase enzymes (IC50 = 1.17 and 0.93 mg/mL, respectively) was investigated. In vitro colonic fermentation experiments revealed that KTS increased the abundance of Firmicutes/Bacteroidetes and butyric acid-producing bacteria. The study showed that the developed gel-loading system plays a vital role in delivering bioactive substances, achieving slow release, and increasing the abundance and diversity of intestinal flora.

Curcumin loaded Zein-alginate nanogels with "core-shell" structure: formation, characterization and simulated digestion.

Zein nanoparticles tend to aggregate in water and are readily digested by enzymes in the gastrointestinal tract. In current study, the Zein-alginate nanogels loaded with curcumin (Cur@ZA) were fabricated with the "core-shell" structure. The Zein "core" was prepared via antisolvent precipitation method, and the alginate gel "shell" was formed by calcium-induced gelation method. The physicochemical properties, microstructure, encapsulation efficiency, stability and simulated digestion characteristics of nanogels were investigated. The results showed that Cur@ZA formed uniform gel spheres with small particle size (415.10 nm), while possessing a dense gel shell on the surface. The Zein "core" and alginate gel "shell" of Cur@ZA are tightly bound to each other by electrostatic adsorption, hydrophobic interaction and hydrogen bonding. Curcumin was able to be loaded in the Cur@ZA nanogels with a higher encapsulation rate (>92 %). Compared with the system which was not induced by calcium ion, the addition of calcium ions improved the photostability and thermal stability of curcumin, and facilitated slow and sustained release of curcumin in the simulated digestion. Therefore, this novel nanogel delivery system has the ideal physicochemical properties, stability and control-release ability, which has the potential to be used in the food industry.

Quality characteristics and gastrointestinal fate of low fat emulsified sausage formulated with konjac glucomannan/oat ß-glucan composite hydrogel.

The objective of present study was to evaluate the utilization of konjac glucomannan/oat ß-glucan composite hydrogel as partial or complete fat replacer on the quality characteristics and gastrointestinal fate of emulsified sausages. The obtained results indicated that in comparison to control emulsified sausage sample, the incorporation of composite hydrogel at a 75 % fat replacement level could not only enhance emulsion stability, water holding capacity (WHC), and compact structure of formulated emulsified sausage, but also decrease their total fat content, cooking loss, hardness, and chewiness. The in vitro digestion results suggested the addition of konjac glucomannan/oat ß-glucan composite hydrogel reduced the protein digestibility of emulsified sausage, while it did not change the molecular weight of digestive products. The confocal laser scanning microscopy(CLSM) image showed the addition of composite hydrogel changed the size of fat and protein aggregate of emulsified sausage during digestion. Based on these findings, the fabrication of composite hydrogel containing konjac glucomannan and oat ß-glucan was a promising strategy as fat replacer. Furthermore, this study provided a theoretic basis for designing composite hydrogel based fat replacers.

Pomelo peel derived nanocellulose as Pickering stabilizers: Fabrication of Pickering emulsions and their potential as sustained-release delivery systems for lycopene.

Two kinds of nanocellulose (cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs) were synthesized from pomelo peels via a facile approach of TEMPO oxidation and sulfuric acid treatment respectively. The FTIR results illustrated that hemicelluloses and lignin were completely removed from the pomelo peel cellulose substrate. The obtained CNFs and CNCs possessed a uniform morphology and nanoscale particle size. The stability of CNF-based Pickering emulsions was higher than that of emulsions stabilized with CNCs, due to the formation of gel structure induced by the CNFs' longer fibrils. Increased oil fractions enhanced the viscoelasticity of CNF-based Pickering emulsions. The in vitro digestion results suggested that increased oil fractions decreased the lipolysis degree, as a result of the larger droplet size and higher viscoelasticity of emulsion. The release of lycopene showed a trend similar to that of FFA release, suggesting that higher oil fractions were beneficial for controlling lycopene release during gastrointestinal digestion.

Release of bound polyphenols from wheat bran soluble dietary fiber during simulated gastrointestinal digestion and colonic fermentation in vitro.

Dietary fiber can act as a carrier of bound phenolics in the distal tracts of the gut, where potential microbial processing occurs, but specific mechanism is unclear. This study aimed to evaluate the release characteristic and activity of bound polyphenols from wheat bran soluble dietary fiber (SDF) during simulated gastrointestinal digestion and colonic fermentation in vitro. The result suggested that the bioaccessibility of bound polyphenols in colonic fermentation was 7.42 times that in gastrointestinal digestion stage. Gallic acid, p-hydroxybenzoic acid and vanillic acid were the most abundant polyphenol metabolites after the fermentation for 6 h. The released phenolics exhibited strong radical scavenging activity (DPPH, 99.22 ± 2.05 µmol TE/100 g DW; ABTS, 330.27 ± 3.56 µmol TE/100 g DW). Fecal fermentation of SDF significantly reduced the value of F/B and stimulated the growth of beneficial bacteria, such as Bacteroides, Akkermansia, and Faecalibacterium. Therefore, bound polyphenols may maintain gut health through their prebiotic activity.

Fabrication and Characterization of Konjac Glucomannan/Oat ß-Glucan Composite Hydrogel: Microstructure, Physicochemical Properties and Gelation Mechanism Studies.

The aim of this study was to evaluate the effect of oat ß-glucan on the formation mechanism, microstructure and physicochemical properties of konjac glucomannan (KGM) composite hydrogel. The dynamic rheology results suggested that the addition of oat ß-glucan increased the viscoelastic modulus of the composite hydrogel, which was conducive to the formation of a stronger gel network. Gelling force experiments showed that hydrogen bonds and hydrophobic interactions participated in the formation of the gel network. Textural profile analysis results found that the amount of oat ß-glucan was positively correlated with the elasticity, cohesiveness and chewiness of the composite hydrogel. The water-holding capacity of the composite hydrogel was enhanced significantly after the addition of oat ß-glucan (p < 0.05), which was 18.3 times that of the KGM gel. The thermal stability of KGM gel was enhanced after the addition of oat ß-glucan with the increase in Tmax being approximately 30 °C. Consequently, a composite hydrogel based on KGM and oat ß-glucan was a strategy to overcome pure KGM gel shortcomings.

Hypoglycemic Activity of Self-Assembled Gellan Gum-Soybean Isolate Composite Hydrogel-Embedded Active Substance-Saponin.

In order to avoid hemolysis caused by direct dietary of kidney tea saponin, complex gels based on gellan gum (GG) and soybean isolate protein (SPI) loaded with saponin were created in the present study by using a self-assembly technique. Studies were conducted on the rheological characteristics, encapsulation effectiveness, molecular structure, microstructure, and hypoglycemic activity of GG/SPI-saponin gels. Increasing the concentration of SPI helped to enhance the strength and energy storage modulus (G') of the gels, and the incorporation of high acylated saponin allowed the whole gel to undergo sol-gel interconversion. The encapsulation efficiency showed that GG/SPI-saponin was 84.52 ± 0.78% for saponin. Microstructural analysis results suggested that GG and SPI were bound by hydrogen bonds. The in vitro digestion results also indicated that saponin could be well retained in the stomach and subsequently released slowly in the intestine. In addition, the in vitro hypoglycemic activity results showed that the IC50 of encapsulated saponin against α-glucosidase and α-amylase were at 2.4790 mg/mL and 1.4317 mg/mL, respectively, and may be used to replace acarbose for hypoglycemia.

Dietary intervention in depression - a review.

Depression is a mental illness that affects the normal lives of over 300 million people. Unfortunately, about 30% to 40% of patients do not adequately respond to pharmacotherapy and other therapies. This review focuses on exploring the relationship between dietary nutrition and depression, aiming to find safer and efficient ingredients to alleviate depression. Diet can affect depression in numerous ways. These pathways include the regulation of tryptophan metabolism, inflammation, hypothalamic-pituitary-adrenal (HPA) axis, microbe-gut-brain axis, brain-derived neurotrophic factor (BDNF) and epigenetics. Furthermore, probiotics, micronutrients, and other active substances exhibit significant antidepressant effects by regulating the above pathways. These provide insights for developing antidepressant foods.

Rational design cold-set interpenetrating network hydrogel based on wheat bran arabinoxylans and pea protein isolates for regulating the release of riboflavin in simulated digestion.

Cold-set interpenetrating polymer network gels as riboflavin (RF) delivery vehicles based on wheat bran arabinoxylans (AX) and pea protein isolate (PPI) were developed via enzymatic-crosslinking. The impact of AX concentrations on the physicochemical property, in vitro digestion property and microstructure of IPN gels was explored. Increased concentrations of AX enhanced the viscoelasticity of IPN gels and resulted in a more compact microstructure. However, at a concentration of 5.0 % (w/v), the faster and stronger crosslinking of AX molecules caused separate network gel between PPI and AX. The IPN gel improved the encapsulation efficiency and release property of embedded RF as compared to PPI gel. SEM results showed that IPN gel maintained a complete network structure after gastric digestion. Particularly, the IPN gel with 1.0 % AX exhibited a homogeneous and complete network structure even after intestinal digestion, which explained the reason for the highest encapsulation efficiency and lowest release ratios of RF.

Design and structural characterization of edible double network gels based on wheat bran arabinoxylan and pea protein isolate.

Double network (DN) gels based on wheat bran arabinoxylan (WBAX) and pea protein isolate (PPI) were fabricated by a two-step sequential gelation method with laccase catalyzed cross-linking followed by heating. The rheological properties, water holding capacity, microstructure and molecular structure of WBAX/PPI DN gels were investigated. Increasing the concentrations of WBAX and PPI contributed to an enhanced viscoelastic modulus of DN gel, which exhibited an interconnected, bicontinuous and compact structure with smaller pore sizes, as a result of higher cross-linking intensity of WBAX molecules. Low field nuclear magnetic resonance (LF-NMR) results showed that increasing the contents of PPI and WBAX could further restrict the water mobility within DN gel, which was beneficial for enhancing the water holding capacity of gel samples. The molecular structure analysis showed that the crosslinking of WBAX-WBAX, PPI-PPI and WBAX-PPI participated in the formation of WBAX-PPI DN gels.

Licorice extract ameliorates hyperglycemia through reshaping gut microbiota structure and inhibiting TLR4/NF-κB signaling pathway in type 2 diabetic mice.

Previous studies suggested that licorice possessed hypoglycemic activity, but its anti-diabetic mechanism has not been clearly illustrated. Herein, we aimed to investigate the hypoglycemic activity and underlying hypoglycemic mechanisms of licorice extract (20, 40, and 80 mg kg-1day-1) in type 2 diabetes mice. The results showed that licorice extract could improve the levels of fasting blood glucose, insulin resistance, serum lipids, and endotoxemia-related colonic inflammation in diabetic mice in a dose-dependent manner. Western blots also suggested that a high-dose licorice extract could effectively decrease the levels of nuclear factor kappa-B (NF-κB), toll-like receptor 4 (TLR4), and tumor necrosis factor-α (TNF-α) in colon of diabetic mice. More importantly, all the doses of licorice extract reshaped the gut microbiota by decreasing the contents of Lachnospiraceae_NK4A136_group at the genus level and increasing the contents of Alloprevotella, Bacteroides, and Akkermansia, especially for the high-dose of licorice extract. These results indicated that the anti-diabetic effect of licorice extract might be attributed to the regulation of the gut microbiota and the colon TLR4/NF-κB signaling pathway in diabetic mice. Thus, licorice extract can be a promising dietary agent to improve type 2 diabetes.

Development and characterization of novel bigels based on monoglyceride-beeswax oleogel and high acyl gellan gum hydrogel for lycopene delivery.

The aim of present study was to develop novel bigels as a semi-solid vehicle for lycopene delivery. Bigels were prepared by using the mixture of glycerol monostearate (GMS)-beeswax based oleogel and high acyl gellan gum hydrogel in different proportions. The confocal microscopic observations showed that the obtained bigels were oleogel-in-hydrogel, and droplets became larger with increased contents of oleogel. Higher fractions of oleogel increased the mechanical strength (storage modulus, firmness) of bigels. According to the rheological results, all bigels exhibited solid-like characteristics since the storage modulus were larger than loss modulus. DSC results showed that the melting temperature of bigel was higher than that of oleogel. During in vitro simulated gastrointestinal digestion, the total release percentages varied from 60% to 80%, and a higher content of oleogel within bigels could slower down the release of lycopene, suggesting that a higher proportion of oleogel was beneficial for delivery of fat-soluble nutraceuticals.

Genetic Causes of Non-pathogenic Pseudomonas syringae pv. actinidiae Isolates in Kiwifruit Orchards.

Bacterial canker disease has become the largest threat to kiwifruit cultivation and production. A monomorphic subpopulation of Pseudomonas syringae pv. actinidiae biovar 3 (Psa3) is responsible for the pandemic worldwide. Diversity in pathogenicity has been found in the pandemic subpopulation and in other Psa3 subpopulations causing epidemics in China. However, the genetic bases have not yet been elucidated. In this study, 117 Psa3 isolates were identified by Psa- and Psa3-specific primers, and evaluated for pathogenicity. Three isolates G4, G40, and S2 are not pathogenic to kiwifruit and do not elicit hypersensitivity responses (HRs) in non-host Nicotiana benthamiana leaves. Two isolates, G25 and G35, exhibited attenuated HR-eliciting activity in non-host N. benthamiana, but they exhibited greatly and slightly reduced pathogenicity in host plants, respectively. The genomes of the five isolates were sequenced and compared with closely related isolates revealed by MLVA and whole-genome typing methods. The candidate genetic loci responsible for the changes in pathogenicity and HR elicitation, were further evaluated by allele replacement experiments. We found that the three non-pathogenic isolates were formed due to the independent, identical insertion events of ISPsy36 transposon in the hrpR gene, encoding a key regulator of type III secretion system (T3SS) and type III effectors (T3Es). In the symptomatic sample from which G4 was isolated, 27% HR negative isolates were detected. In isolate G25, transposon insertion of ISPsy32 at the non-coding sequence upstream of the hrpR gene was detected, similar to a previously reported low-virulent Psa3 strain M227. In isolate G35, we detected disruptions of T3Es hopBB1-1 and hopBB1-2, which induce HR in N. benthamiana leaves revealed by Agrobacterium tumefaciens infiltration. These phenotype-changed isolates were formed at low frequencies during the course of pathogen infection in host plants, supported by the binding assay of ISPsy32 and the non-coding DNA sequences upstream of the hrpR gene, the co-isolation of the virulent isolates belonging to the same MLVA clade, and the low levels of transcription of the transposon genes. Taken together, in terms of short-term field evolution, transposon insertions in the T3SS-related genes resulted in the formation of non-pathogenic and low-virulent Psa3 isolates.

Improved physicochemical stability of emulsions enriched in lutein by a combination of chlorogenic acid-whey protein isolate-dextran and vitamin E.

Lutein, as a bioactive substance, has the ability to decrease the risk of some chronic diseases, but the poor water solubility, chemical instability, and low bioaccessibility limit its wide application in foods. In this study, an emulsion-based delivery system stabilized by chlorogenic acid (CA)-whey protein isolate (WPI)-dextran (DEX) ternary conjugates was prepared and vitamin E (VE) was added to increase the chemical stability of lutein. Molecular weight and conformational information of ternary conjugates were obtained by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, fluorescence spectroscopy, and Fourier transform infrared spectroscopy. o-Phthalaldehyde results suggested that the extent of glycation was 16.4% and 19.5% for (CA-WPI)-DEX and WPI-DEX conjugates, respectively. The physicochemical stability of lutein-enriched emulsions was evaluated under different environmental stresses and long-term storage. The obtained results showed that compared with emulsions stabilized by WPI alone or binary conjugates, ternary conjugates imparted emulsions high stability under different environmental stress conditions (ionic strength, freeze-thaw, and heat) and long-term storage (within 3 weeks). VE can effectively decrease the degradation rate of lutein without changing the physical stability of emulsions. Additionally, the lutein-enriched emulsions prepared by ternary conjugates and VE exhibited a relatively high bioaccessibility. PRACTICAL APPLICATION: The ternary conjugates constructed in this paper has excellent physicochemical characteristics to stabilize emulsion, and can increase the water solubility of functional factors and reduce their degradation rate. Additionally, this conjugate was prepared by food-grade materials. Therefore, it can be used as emulsion-based delivery systems in food industrials.

Review on the Stability Mechanism and Application of Water-in-Oil Emulsions Encapsulating Various Additives.

Water-in-oil (W/O) emulsions can be used to encapsulate and control the release of bioactive compounds for nutrition fortification in fat-based food products. However, long-term stabilization of W/O emulsions remains a challenging task in food science and thereby limits their potential application in the food industry. To develop high-quality emulsion-based food products, it is essential to better understand the factors that affect the emulsions' stability. In real food system, the stability situation of W/O emulsions is more complicated by the fact that various additives are contained in the products, such as NaCl, sugar, and other large molecular additives. The potential stability issues of W/O emulsions caused by these encapsulated additives are a current concern, and special attention should be given to the relevant theoretical knowledge. This article presents several commonly used methods for the preparation of W/O emulsions, and the roles of different additives (water- and oil-soluble types) in stabilizing W/O emulsions are mainly discussed and illustrated to gain new insights into the stability mechanism of emulsion systems. In addition, the review provides a comprehensive and state-of-art overview of the potential applications of W/O emulsions in food systems, for example, as fat replacers, controlled-release platforms of nutrients, and delivery carrier systems of water-soluble bioactive compounds. The information may be useful for optimizing the formulation of W/O emulsions for utilization in commercial functional food products.

Physical stability, microstructure and micro-rheological properties of water-in-oil-in-water (W/O/W) emulsions stabilized by porcine gelatin.

Water-in-oil-in-water (W/O/W) emulsions could be utilized for fat-reduced food formulation and delivery of bioactive nutrients. However, due to thermodynamic instability, it is difficult to prepare stable double emulsions. The purpose of this study was to improve the stability of W/O/W double emulsions containing 2.0 M MgCl2 by adding porcine gelatin in the inner water phase. The impact of gelatin on the physical stability, microstructure and micro-rheological properties of W/O/W emulsions was investigated. It was found that, when the concentration of porcine gelatin exceeded 4.0 wt%, the stability of emulsions was improved, due to increased viscoelasticity of emulsion droplets. When MgCl2 concentration increased to 2.0 M, the particle size of emulsions increased, due to the osmotic pressure gradient, and the presence of gelatin further increased the droplet size. Confocal microscopy results showed that the presence of gelatin could improve the stability of W/O/W emulsions against coalescence。.