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Background: Natural myofibrillar protein (MP) is sensitive to changes in the microenvironment, such as pH and ionic strength, and therefore can adversely affect the final quality of meat products. The aim of this study was to modify natural MP as well as to improve its functional properties. Therefore, the quality improvement effect of konjac polysaccharides with different concentrations (0, 1.5, 3, 4.5 and 6 g kg−1 protein) on MP gels was investigated. Results: With a concentration of konjac polysaccharides of 6 g kg−1 protein, the composite gel obtained exhibited a significant improvement of water binding (water holding capacity increased by 7.71%) and textural performance (strength increased from 29.12 to 37.55 N mm, an increase of 8.43 N mm). Meanwhile, konjac polysaccharides could help to form more disulfide bonds and non‐disulfide covalent bonds, which enhanced the crosslinking of MP and maintained the MP gel network structure. Then, with the preservation of α‐helix structure (a significant increase of 8.11%), slower protein aggregation and formation of small aggregates, this supported the formation of a fine and homogeneous network structure and allowed a reduction in water mobility. Conclusion: During the heating process, konjac polysaccharides could absorb the surrounding water and fill the gel system, which resulted in an increase in the water content of the gel network and enhanced the gel‐forming ability of the gel. Meanwhile, konjac polysaccharides might inhibit irregular aggregation of proteins and promote the formation of small aggregates, which in turn form a homogeneous and continuous gel matrix by orderly arrangement. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Dangke cheese (DC) is a traditional cheese from Enrekang Regency, South Sulawesi, Indonesia. The functional dangke cheese (FDC) was developed from DC with product diversification to obtain new cheese variants. FDC is hard cheese (HC) through fermentation, ripening, and coating processes. Therefore, the EF becomes an alternative for coating HC because it can maintain product mass, shelf life, and flavor. This study is aimed at determining edible film (EF) characteristics and analyzing EF's prospects in coating HC. The research method was conducted in two stages. The first stage was to make a whey base EF solution with 1%, 1.5%, and 2% KF. The EF was analyzed using a randomized complete block design. The analysis result of whey-based EF combined with KF was then conducted in the second stage of the research by applying HC produced in the laboratory and then stored for 0, 10, 20, and 30 days, respectively. Physical tests such as pH and organoleptic were carried out using factorial pattern group randomized design analysis. The results of the first stage of the study showed that EF from whey combined with KF had a very significant effect (P < 0.01) on EF parameters (gelation time, thickness, extensibility, tensile strength, and water vapor transmission rate (WVTR)). The results of the second stage of the study showed that EF applied to HC using different storage lengths had a significant effect (P < 0.01) on color and liking but no significant effect (P > 0.05) on pH and texture parameters. Meanwhile, HC without EF coating has a significant impact (P < 0.01) on texture and color parameters but no significant effect (P > 0.05) on pH, aroma, and liking. 1.5% KF in an EF formulation is the best. HC coated with EF was more durable (20 days) than HC without EF (10 days). [ABSTRACT FROM AUTHOR]

Konjac species (Amorphophallus spp.) are the only plant species in the world that are rich in a large amount of konjac glucomannan (KGM). These plants are widely cultivated as cash crops in tropical and subtropical countries in Asia, including China. Pectobacterium carotovorum subsp. carotovorum (Pcc) is one of the most destructive bacterial pathogens of konjac. Here, we analyzed the interactions between Pcc and susceptible and resistant konjac species from multiple perspectives. At the transcriptional and metabolic levels, the susceptible species A. konjac and resistant species A. muelleri exhibit similar molecular responses, activating plant hormone signaling pathways and metabolizing defense compounds such as phenylpropanoids and flavonoids to resist infection. Interestingly, we found that Pcc stress can lead to rapid recombination of endophytic microbial communities within a very short period (96 h). Under conditions of bacterial pathogen infection, the relative abundance of most bacterial communities in konjac tissue decreased sharply compared with that in healthy plants, while the relative abundance of some beneficial fungal communities increased significantly. The relative abundance of Cladosporium increased significantly in both kinds of infected konjac compared to that in healthy plants, and the relative abundance in resistant A. muelleri plants was greater than that in susceptible A. konjac plants. Among the isolated cultivable microorganisms, all three strains of Cladosporium strongly inhibited Pcc growth. Our results further elucidate the potential mechanism underlying konjac resistance to Pcc infection, highlighting the important role of endophytic microbial communities in resisting bacterial pathogen infections, especially the more direct role of fungal communities in inhibiting pathogen growth. [ABSTRACT FROM AUTHOR]

Synthesized a kind of polyacrylamide konjac gum double network gel system, and studied the possibility of replacing mechanical bridge plug with this system. Studied the effects of covalent bond cross-linking, ionic bond cross-linking and monomer ratio on the mechanical properties of gel, including the stress-strain curve, elastic modulus, critical stretch and fracture energy. And conducted indoor simulation wellbore sealing experiments. The results show that the double network gel has higher strength than the single network gel, and the plugging ability of the well bore is greatly improved, which is expected to replace the mechanical bridge plug in construction. [ABSTRACT FROM AUTHOR]

BACKGROUND: Polysaccharide hydrogel is one of the most important materials for the colon target drug release system. However, the degradation time of polysaccharide hydrogel is much longer than the retention time in the colon. The drugs are expelled from the body before being released. OBJECTIVE: In order to match the degradation of drug carriers and their retention time in the colon, a rapidly degradable konjac glucomannan (KGM) hydrogel was designed for colon target drug release. METHODS: A crosslinker containing azo bond, olsalazine, was used to prepare the rapidly degradable KGM hydrogel. The degradation and drug release of the hydrogels with different crosslinking densities in the normal buffer and the human fecal medium were studied to evaluate the efficiency of colon drug release. RESULTS: More than 50% of the KGM hydrogel by weight was degraded and more than 60% of the 5-fluorouracil (5-Fu) was released within 48 h in 5% w/v human fecal medium. CONCLUSION: The drug was released more rapidly in a simulated colon environment than in a normal buffer. Furthermore, the drug release was controlled by the degradation of the hydrogel. The KGM hydrogel containing azo crosslinker has great potential for colon drug release. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the effects of different cellulose nanofibers (CNF, 0–20% w/w) and aluminum oxide nanoparticles (Al2O3 NPs, 0–4% w/w) concentrations on the properties of deacetylated konjac glucomannan (DKGM) base film, as well as the protective performance of DKGM-based composite film on wood. The addition of CNF primarily improves the mechanical properties of the film. Compared to the KGM base film, the DKGM/CNF composite base film (DKC) exhibits excellent tensile strength and elongation at break, with increases of 44.39 MPa and 19.87%, respectively. After application to the wood surface, the glossiness of the wood increased by 43.48%, and the moisture absorption dimensional change rates reached 0.07% (radial) and 0.11% (tangential), while the moisture absorption coefficients decreased to 0.008 (radial) and 0.019 (tangential). The addition of Al2O3 NPs primarily improves the film's resistance to ultraviolet light and water. Compared to the DKGM base film, the water contact angle, water solubility, and water vapor barrier performance of the DKGM/ Al2O3 composite base film (DKA) significantly improved. When applied to the wood surface, the wood wear resistance and aging resistance increased by 62% and 69.67%, respectively. Therefore, DKGM base films doped with CNF and Al2O3 NPs have broad development prospects in the field of wood protection. [ABSTRACT FROM AUTHOR]

In recent years, proteins and polysaccharides have been widely used to prepare environmentally friendly functional food packaging materials. However, films based only on proteins or polysaccharides perform poorly and are often used as polymer matrices blended with biologically active ingredients to prepare films. In this paper, sodium caseinate (CAS), xanthan gum (XG), and konjac glucomannan (KGM) were used as raw materials, and clove oil (CEO) was added for the development of reactive biopolymer films, with the aim of exploring the effect of CEO on the structure and physical properties of films. The morphology, rheological behavior, optical properties, thermodynamic properties and mechanical properties of the composite films were investigated. The interaction between clove oil and film matrix was determined by Fourier infrared spectroscopy, and the distribution of CEO in the network structure of the films and the compatibility properties with the film matrix were investigated by scanning electron microscopy and laser confocal microscopy. It was found that with the increase of CEO content, the film color deepened, the optical properties were modulated, the surface hydrophobicity was enhanced and the thermodynamic properties did not change significantly. The study showed how the combination of konjac glucomannan and xanthan gum colloids with clove essential oil and sodium caseinate can affect the properties of bioactive films. [ABSTRACT FROM AUTHOR]

Natural silk fibroin nanofibers (SNF) have recently attracted great attention in the field of biomaterials due to their excellent biocompatibility, outstanding mechanical properties, and biomimetic nanostructures. However, the poor structural stability of SNF assembly in aqueous conditions remains a major obstacle to their biomedical application. In this work, SNF scaffolds with extracellular matrix‐mimicking architecture and tunable properties were developed by using a small amount of konjac glucomannan (KGM) as a physical adhesive. Fourier transform infrared spectroscopy (FTIR) results revealed that KGM facilitated the formation of hydrogen bond networks between SNF as well as nanofibers/polysaccharide molecules, thereby reinforcing the interconnectivity between SNF. The water stability test showed that SNF scaffolds exhibited good structural stability in water when the mass ratio of KGM/SNF reached 2.5/100. Raising KGM content significantly enhanced the compression strength, modulus, and swelling ratio of the porous scaffold. Whereas, the nanofibrous morphology and porosity of the scaffolds were significantly sacrificed as KGM content exceeded 10% as evidenced by scanning electron microscopy (SEM) results. In vitro, cytocompatibility results also demonstrated the excellent biocompatibility of the biomimetic nanofibrous scaffolds, and the high porosity significantly enhanced cell viability. These results suggest that KGM‐reinforced SNF scaffolds may serve as promising candidates for biomaterial applications. [ABSTRACT FROM AUTHOR]

Market demand for food packing bags is large. However, low mechanical properties and strong electrostatic damage limit their use. In this work, carrageenan/konjac glucomannan/graphene oxide (GO) nanocomposite films were prepared by solution casting. First, Hummers method was used to obtain GO nanosheets. Then, GO-filled composites (various GO dosages) were fabricated. Surface morphology of films was investigated. After that, stress–strain curves of films were determined, and mechanical properties of films after 80 °C thermal aging were studied. In the end, electrical and thermal conductivities of films were measured. GO can play an important role in improving mechanical, antistatic and heat-conducting performances of films. The optimal composite (3.6 wt% GO) can exhibit promising features including a high breaking strength of ~ 130 MPa (~ 65 MPa after 80 °C thermal aging for 30 min), high electrical conductivity of ~ 0.01 S m−1 at 20 Hz under 1 V and high thermal conductivity of ~ 0.74 W m−1 K−1 at room temperature. This research will favor a large-scale fabrication of functional and environmental composites for food packaging. [ABSTRACT FROM AUTHOR]

In this study, the effect of konjac glucomannan (KGM, 0–5%) on the structure, physicochemical properties, and in vitro digestibility of extruded yam starch (EYS) was investigated. The EYS became rougher on the surface and the particle size increased as observed using scanning electron microscopy and particle size analysis. X-ray diffraction and Raman results revealed that the relative crystallinity (18.30% to 22.30%) of EYS increased, and the full width at half maxima at 480 cm−1 decreased with increasing KGM content, indicating the increment of long-range and short-range ordered structure. Differential scanning calorimetry and rheological results demonstrated that KGM enhanced thermal stability and the gel strength of EYS due to enhanced interaction between KGM and YS molecules. Additionally, a decrease in the swelling power and viscosity of EYS was observed with increased KGM content. The inclusion of KGM in the EYS increased the resistant starch content from 11.89% to 43.51%. This study provides a dual-modified method using extrusion and KGM for modified YS with high thermal stability, gel strength, and resistance to digestion. [ABSTRACT FROM AUTHOR]

Background: Goose liver oil (GLO) is a solid–liquid mixture, rich in polyunsaturated fatty acids and high in nutritional value, but poor in fluidity and easily oxidized. Therefore, oil‐in‐water (O/W) Pickering emulsions of three polysaccharides and soy protein isolate (SPI) with GLO were prepared to improve the stability of it. Results: Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE), Fourier‐transform infrared spectroscopy, and zeta potential revealed that the SPI and complexes with konjac glucomannan, pectin, and guar gum (GG) ranged from 17 to 75 kDa, with the site of action being the –OH stretch and the amide group, and bound by hydrogen bonding. Adding konjac glucomannan and GG significantly increased the water contact angle of the SPI to 74.1° and 59.0°, respectively. Therefore, the protein–polysaccharide complexes could enhance the emulsion stability. In addition, the O/W Pickering emulsions with GLO had near‐Newtonian fluid rheological properties with a significant increase in apparent viscosity and viscoelasticity, forming a dual network structure consisting of a ductile and flexible protein network and a rigid and brittle polysaccharide network. The microstructure observation indicated that the O/W emulsions were spherical and homogeneous. The highest emulsification activity was observed for the SPI–GG–GLO emulsions, without significant delamination or flocculation and high oxidative stability after 7 days in storage. Conclusion: These results demonstrate that the construction of SPI–GG–GLO O/W Pickering emulsions can stabilize GLO even at high temperatures that promote oxidation. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In this study, nanofiber films were prepared by electrospinning technology with polyvinyl alcohol (PVA) and konjac glucomannan (KGM) as raw materials. Tea polyphenols (TPs) were incorporated in the above matrix, which increased physicochemical (thermal and mechanical characteristics) and antibacterial properties of the nanofiber films. The release behavior of phenolic compounds from PVA/KGM-TPs nanofiber films was determined in different food simulants; antioxidant and antibacterial activity of the films were also evaluated. The results showed that the addition of KGM increased the physical and chemical properties of the films. The tensile strength (TS) and elongation at break (EB) increased from 5.40 ± 0.33 to 10.62 ± 0.34 and from 7.24 ± 0.32 to 18.10 ± 0.91, respectively. PVA/KGM-TPs nanofiber films performed controlled release of TPs, with final release of 49.17% in 3% acetic acid, 43.6% in 10% ethanol, and 59.42% in 95% ethanol. The nanofiber films showed good antioxidation properties, with the free radical scavenging rate increasing from 1.33% to 25.61%, and good antibacterial properties with inhibition zones against E. coli and S. aureus of 24.33 ± 0.47 mm and 34.33 ± 0.94 mm, respectively. In addition, the as-prepared films showed significant preservation performance for raw bananas at 25 °C. [ABSTRACT FROM AUTHOR]

The application of Plackett–Burman design in investigating the effect of physicochemical attributes of multispecies surimi was performed. The surimi was made from five species, added with four types of cryoprotectant and two different gelling agents, thus constructing 11 processing variables. Surimi was observed for the physico-chemical parameters including moisture, salt-soluble protein, pH, hardness, whiteness degree, and water-holding capacity and sensory evaluation. The best formulation was obtained from consisting of threadfin bream, croaker, lattice monocle bream, tilapia, sorbitol, sucrose, sodium tripolyphosphate, k-carrageenan, sodium lactate, and konjac with 15 min stirring period. [ABSTRACT FROM AUTHOR]

During freeze‐drying, the degradation or eutectic melting of duck blood proteins can reduce the quality of duck blood gels. However, the interaction between proteins and polysaccharides during drying can improve protein‐based gel quality. Therefore, here, we investigated the physicochemical properties of heat‐induced gels of freeze‐dried duck blood (FDB) and FDB with different proportions of the polysaccharide konjac glucomannan (KG), which serves as a freeze‐denaturation inhibitor agent (FDA) or binder (BG). The pH and water‐holding capacity (WHC) of FDB + KG gels were higher than those of FDB gel without KG (control). Especially, the WHC increased from 11.00% for control to 55.65% for FDB gel with 1% KG as a BG. Consequently, cooking loss and texture parameters of FDB + KG gels decreased. The hardness of control was 2.14 kg, which significantly reduced to 0.12–0.87 kg with KG addition. The highest carbonyl content was observed in control gel, and the thiobarbituric acid reactive substance content was reduced by the addition of 1% KG as an FDA (T1) or 0.8% KG as an FDA with 0.2% KG as a BG (T2) (p < 0.05). These changes might be induced by the alteration of tertiary structure and thermodynamic stability of gels. In conclusion, 1% KG can be used as an FDA to improve the quality and physicochemical properties of heat‐induced gels of FDB. Optimized FDB gels with KG can be used as an innovative food ingredient to fortify nutrition and develop special dietary purposes. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This work determined and analyzed the complete chloroplast genome sequence of Amorphophallus konjac K. Koch ex N.E.Br 1858 from Yunnan, China. The genome size was 167,470 bp, of which contains a large single-copy region (LSC 93,443 bp), a small single-copy region (SSC 21,575 bp), and a pair of inverted repeat regions (IR 26,226 bp). The chloroplast genome has 131 genes, including 86 protein-coding genes, 37 tRNAs, and eight rRNAs. A previous study reported deletion of accD, psbE, and trnG-GCC genes in the A. konjac chloroplast genome. Our study supports the conservative structure of A. konjac and does not support the gene deletion mentioned above. Phylogenetic analysis indicated that A. konjac shares a close relationship with another A. konjac (collected from Guizhou) and A. titanium by forming a clade in the genus Amorphophallus. Our results provide some useful information to the evolution of the family Araceae. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Our previous study revealed that dietary konjac flour (KF) could remodel gut microbiota and improve reproductive performance of sows, but its underlying mechanisms remain unclear. This experiment aimed to investigate how dietary KF improves reproductive performance of obese sows. Here, 60 sows were assigned into three groups according to their backfat thickness: normal backfat sows fed with control diet (CON-N), high backfat sows fed with control diet (CON-H) and high backfat sows fed with KF inclusion diet (KF-H). The characteristics of sows and piglets were recorded. Next, fecal microbiota transplantation (FMT) was performed on female mice, followed by recording the characteristics of female mice. The results showed that compared with CON-H group, KF-H group showed downtrend in stillbirth rate (P = 0.07), an increase in placental efficiency (P < 0.01) and average piglet weight (P < 0.01); coupled with a decrease in the values of homeostasis model assessment-insulin resistance (P < 0.01); as well as an increase in placental vascular density and protein expression of angiogenesis markers (P < 0.01). As expected, sows fed KF diets had improved abundance and diversity of gut microbiota. More importantly, compared with CON-H(FMT) group, KF-H(FMT) group showed improvement in reproductive performance and insulin sensitivity (P < 0.05), as well as an increase in placental labyrinth zone and protein expression of angiogenesis markers (P < 0.05). Furthermore, we found a content increase (P < 0.05) of SCFAs in both KF-H group sow and KF-H (FMT) group mice. Overall, KF supplementation could alleviate insulin resistance, promote placental angiogenesis, and ultimately improve the reproductive performance of sows via gut microbiota remodeling. [ABSTRACT FROM AUTHOR]

This study aimed to formulate and evaluate a floating raft system for the co-delivery of etoricoxib (ETO) and famotidine (FAM) using a combination of glucomannan with natural/semi-synthetic polysaccharides. Formulation variables affect gelation lag time (GLT), floating lag time (FLT), and release percentage of drugs after 1–8 h, Stability, and viscosity parameters were evaluated. In vivo X-ray studies, followed by the pharmacokinetic study, were performed on human volunteers. Formulations exhibited pseudoplastic behavior for ease of swallowing. The optimum raft system (ORS) comprised 1% Na alginate, 0.1% Low Methoxyl (LM) pectin, 0.8% Konjac glucomannan (KGL), 1% Precirol, and 1% CaCO3. ORS exhibited rapid GLT and FLT (around 42 and 8 sec respectively) in 0.1 N HCl as well as controlled release of ETO (15% in 1 h and 82% in 8 h) and FAM (29% in 1 h and 85% in 8 h). Formulation stability with the absence of any drug-excipient interactions was observed. The X-ray imaging showed a promising buoyancy ability for approximately 8 h. Compared with marketed products, ORS showed superior relative bioavailability for both drugs. These findings revealed the successful preparation of a promising raft system with improved dual drug delivery. [ABSTRACT FROM AUTHOR]

Plants in the genus Amorphophallus, many of which possess high konjac glucomannan content, are considered important cash crops in many Asian countries. Wild relatives of cultivated Amorphophallus species are valuable resources for the genetic improvement of these crops. To aid in future genetic research of wild germplasm resources of Amorphophallus, a single individual of Amorphophallus krausei Engler, Pflanzenr 1911 was collected from southwestern China, and its chloroplast genome was sequenced using next-generation sequencing technologies. The assembled chloroplast genome was 172,418 bp in length with a GC content of 35.23% (GenBank accession no. OR416863). A typical quadripartite structure was found in the genome, which was comprised of one large single-copy (LSC), one small single-copy (SSC), and two inverted repeats (IRs), with lengths of 91,983 bp, 15,591 bp, 32,422 bp, and 32,422 bp, respectively. A total of 132 genes were annotated in the genome, including 86 protein-coding genes, 38 tRNAs, and 8 rRNAs. A maximum likelihood (ML) tree of A. krausei and 17 other species in the family Araceae suggested that all Amorphophallus species formed a single monophyletic clade. A close relationship among A. konjac, A. albus, and A. krausei was also revealed by the phylogenetic tree. The newly sequenced chloroplast genome of A. krausei will support future genetic studies, particularly the assessment of genetic diversity, resource conservation, and phylogeographic research. [ABSTRACT FROM AUTHOR]

The type and content of carbohydrates in konjac corms are an essential factors in determining the quality of konjac; however, the pattern of carbohydrate changes and the mechanism regulating the development of mother and daughter corms in the "relay growth" process of Amorphophallus muelleri remain unclear. This study aimed to investigate changes in corm carbohydrates during the growth cycle of A. muelleri and to compare the carbohydrate composition and the expression of related genes between mother and daughter corms. Integrated metabolome and RNA-seq analyses identified 37 differential metabolites as well as 8074 genes that were differentially expressed between mother and daughter corms, the majority of which were involved in starch and sucrose metabolism. More than 80% of the differential metabolites, including sucrose and starch, tended to accumulate in the mother corms; however, konjac glucomannan (KGM), as one of the most important carbohydrates and its major component of the corm, accumulated in higher amounts in the daughter corms. In addition, the expression of invertase and alpha-amylase that promote the breakdown of sucrose and starch was 351.78- and 15.63-fold higher, respectively, in the daughter corm, whereas that of the starch synthesis gene AkWAXY was only 0.096 times as high as in the mother corms. Furthermore, the level of cellulose synthase-like protein G, which promotes KGM synthesis, was 3.85 times higher in daughter corms compared to mother corms. Thus, we inferred that the daughter and mother corms had two distinct carbohydrate utilization strategies. This study provides insights into temporal changes in carbohydrates during the growth cycle of A. muelleri. [ABSTRACT FROM AUTHOR]

Background. Periodontitis is an inflammatory disease caused by specific microorganisms that gradually damage the periodontal and tooth-supporting tissues, thereby reducing a person's quality of life. Periodontal disease is closely associated with high reactive oxygen species (ROS) levels, with a high receptor activator of nuclear factor kβ ligand (RANKL)/osteoprotegerin (OPG) ratio. Konjac glucomannan (KGM) is produced from the porang root, which has several properties. For example, it can reduce oxidative stress. The current study analyzed the osteoclastogenesis inhibitory and antioxidant properties of KGM based on histomorphometric findings, RANKL/OPG ratio, and ROS levels in the Swiss Webster mouse periodontitis model. Methods. Eight-week-old male Swiss Webster mice were divided into the nonligation, nonligation + KGM, ligation + Porphyromonas gingivalis, and ligation + P. gingivalis + KGM groups. KGM suspension was administered for 14 days. Periodontitis induction was performed from 7th to 14th day. On the 14th day, maxillae, gingival, and gingival crevicular fluid samples were collected to assess the histomorphometry of bone damage, gene expression ratio of RANKL/OPG, and ROS protein levels. Results. The periodontitis group pretreated with KGM presented with significantly reduced alveolar bone damage, RANKL/OPG ratio, and ROS level than without KGM group. KGM treatment had no harmful/toxic effects in mice. Conclusion. Administration of KGM could act as an adjunctive in periodontal therapy by suppressing periodontal disease via osteoclastogenesis inhibitory and antioxidant properties. [ABSTRACT FROM AUTHOR]

Recently, the natural polymer polysaccharide konjac glucomannan (KGM) has received attention as a promising adsorbent in water treatment due to its low toxicity, cost-effectiveness and biocompatibility. However, the high-level water absorbency of KGM makes it difficult to recover in water treatment. In this study, by combining KGM with magnetic nanoparticles, KGM-based magnetic nanoparticles (KGM-Fe3O4 NPs) with excellent adsorption properties and recyclability for heavy metals were prepared using an one-step precipitation method. The as-prepared KGM-Fe3O4 NPs have a spherical morphology of superparamagnetism with a small particle size (ca. 7.0 nm) and a large specific surface area (160.1 m2·g−1). Taking Cr(VI) as the target heavy metal ion, the above nanoparticles have a high adsorption capacity and fast adsorption rate for Cr(VI). The pseudo-second order kinetic model is more suitable to describe the adsorption process of Cr(VI) by KGM-Fe3O4 NPs, and the maximum adsorption capacity of Cr(VI) onto KGM-Fe3O4 NPs was calculated to be 41.67 mg·g−1 using the Langmuir isotherm model. In addition, KGM-Fe3O4 NPs with adsorbed heavy metal ions can be quickly recovered from a solution, regenerated, and reused in the next cycle. KGM-based Fe3O4 nanoparticles are promising adsorbents that show significant reusability for the removal of metal ions in water and wastewater treatment. [ABSTRACT FROM AUTHOR]

Bletilla striata polysaccharide (BSP) is effective for wound healing and has important applications in health care. A series of blend hydrogels was designed with BSP and konjac glucomannan (KGM) in this study to overcome the deficient mechanical performance caused by the excessive dissolution of BSP without affecting its physiological activity. The interplay between them, as well as the effects of KGM concentration on the physical properties and microstructures of hydrogels, were also explored. It was proved that the frame of the hydrogel was primarily formed by KGM. BSP was dispersed uniformly and linked to KGM through hydrogen bonding, which effectively improved the physical properties, such as increasing the water-holding capacity, improving the swelling degree, and enhancing the mechanical properties. Blend hydrogel BK2-2 (containing 1.0% BSP and 1.0% KGM, w/v) was found to be the optimal formulation based on the thermal stability and microstructure, which was used for further research. In vitro experiments revealed the L929 cell proliferative effects of the blend hydrogel, and no difference was found with BSP sponge extract after 72 h of exposure. In vivo animal studies indicated that the BK2-2 accelerated wound healing compared with the control group; however, no difference was found with dressings only made of BSP. These results demonstrated that KGM improved the physical properties of BSP-based material without negatively affecting its physiological properties. Also, the BSP/KGM blend hydrogel had good comprehensive properties and is expected to be used as a wound healing material in the future. [ABSTRACT FROM AUTHOR]

Soybean protein isolate (SPI), konjac gum and carrageenan were used as raw materials. Konjac gum and carrageenan were mixed in different ratios (1: 0, 2 : 1, 1 : 1, 1 : 2, 0 : 1, mass ratio), and then soybean protein isolate (SPI) was added to prepare heat induced emulsion gel. The influence of different proportions of konjac gum carrageenan on the gel properties of SPI emulsion gel and the related mechanism was studied. It was found that adding different proportions of konjac gum and carrageenan could significantly improve the gel properties of SPI emulsion gel. Moreover, when the ratio of konjac gum and carrageenan was 1 : 2, the obtained emulsion gel had the best gel properties. The average particle size of emulsion decreased from 56. 59 μm to 36. 84 μm and the distribution of emulsion droplets was more uniform. Compared with the control group without adding the composite system, the gel strength increased 371. 98% from 122. 76 g to 579. 40 g, forming a more dense gel network structure. What's more, the viscoelastic and solid properties of the emulsion gel were also greatly improved. [ABSTRACT FROM AUTHOR]

Konjac glucomannan (KGM) is a natural polysaccharide derived from konjac, which has been widely used in various fields due to its numerous beneficial properties. However, the high viscosity and water absorption of KGM limit its application. Compared with KGM, Konjac glucomannan oligosaccharides (KGMOS) have higher water solubility and stronger application value. In this paper, a novel mannanase KgManA was cloned from Klebsiella grimontii to develop a new KGMOS-producing enzyme. Bioinformatic analysis shows that the structural similarity between KgManA and other enzymes was less than 18.33%. Phylogenetic analysis shows that KgManA shares different branches with the traditional mannanases containing the CMB35 domain, indicating that it is a novel mannanase. Then, the enzymatic properties were determined and substrate specificity was characterized. Surprisingly, KgManA is stable in a very wide pH range of 3.0 to 10.0; it has a special substrate specificity and seems to be active only for mannans without galactose in the side chain. Additionally, the three-dimensional structure of the enzyme was simulated and molecular docking of the mannotetraose substrate was performed. As far as we know, this is the first report to characterize the enzymatic properties and to simulate the structure of mannanase from K. grimontii. This work will contribute to the development and characterization of novel K. grimontii-derived mannanases. The above results indicate that KgManA is a promising tool for the production of KGMOS. [ABSTRACT FROM AUTHOR]

Background. Egg noodles are a commonly consumed food in Asia and are increasingly eaten around the world. Consumers now have more new requirements concerning the quality and healthiness of products. Therefore, the objective of this study is to determine the effects of Moringa leaf powder (MLP), konjac glucomannan (KG), and acetylated starch (AS) on the quality of noodles. Materials and methods. The Box-Behnken design via the response surface methodology was used, and cooking quality, weight increase, and cooking loss were the main responses. Quadratic polynomial equations were established to determine the influence of 3 independent variables (MLP, KG, and AS) on the cooking quality of the studied noodles. Results. A significance test and analysis of variance results demonstrated that the MLP, KG, and AS contributed significantly to the increase in rehydration rate and reduction of cooking loss. The joint interaction effects of dependent variables were also significant for cooking quality. Increasing the percentage of MLP and AS resulted in an increase in weight increase and cooking loss, while increasing the percentage of KG resulted in an increase in the rehydration rate and a significant reduction in cooking loss. Based on the fitted model for two responses, simultaneous optimization was also carried out. The optimal values were MLP, KG, and MS at 5%, 4.89%, and 3%, respectively, which gave an estimated maximum value for weight increase (83.61%) and a minimum value for cooking loss (3.05%). A scanning electron micrograph of noodles containing these concentrations showed that the continuity of the gluten network was enhanced. Conclusion. In this study, the parameters of the input variables were optimized to increase the weight of noodles after cooking and reduce the cooking loss, using the response surface methodology. The accuracy of the model has been verified by actual experimental data. The results obtained may provide new insight into the addition of high bioactive compounds available in plants to the formulation of common food products and the development of new food products for the manufacturing industry. [ABSTRACT FROM AUTHOR]

To improve the quality of the characteristics of yellow alkaline noodles and enrich their nutritional value, konjac glucomannan (KGM) with or without chitosan coating were added to noodles, and their application effects were investigated in terms of color, texture, water absorption, starch digestion, total plate count (TPC) and microstructure. Chitosan–konjac glucomannan (CK) complex was firstly prepared by embedding konjac powder with chitosan sol. After embedding, the hydrophilicity of KGM decreased significantly. Then, either CK or native KGM were mixed evenly with flour before saline water, and soda was subsequently added to produce noodles. Compared with native KGM, CK provided the noodles with a higher brightness and a lighter yellow color. In terms of texture properties, although the firmness of CK noodles was weaker than that of KGM noodles, the tensile properties were enhanced. After embedding, the water absorption of CK noodles decreased and the content of resistant starch (RS) in the noodles increased. During storage, the TPC in CK noodles was significantly lower than that in KGM noodles. At a CK content of 5%, the noodles presented a lightness of 87.41, a b value of 17.75, a shear work of 39.9 g·cm, a tensile distance of 84.28 cm, a water absorption of 69.48%, a RS content of 17.97% and a TPC of 2.74 lg CFU/g at 10 days. In general, KGM with chitosan coating could improve the physicochemical qualities of noodles and extend their shelf life to a certain extent. [ABSTRACT FROM AUTHOR]

Egg yolk immunoglobulin (IgY) is a biologically active ingredient with high immunogenicity; however, its instability in the acidic environment of the upper gastrointestinal tract limits its application in oral formulations. In the present work, an encapsulation system based on maltodextrin (MD) and konjac gum (KGM) was developed as a protective carrier for IgY for targeted release to retain stability. A simulated gastric model was used to compare the release characteristics of the different formulations, and to explore the optimal release mode. To better understand the controlled release mechanism of MD and KGM composite tablets, the release curve, macrostructure, microstructure, and water mobility were analysed. Results indicated that the sustained release of IgY from MD and KGM composite tablets was mainly driven by Fick diffusion and dissolution. As the concentration of KGM increased, the release rate of IgY from the tablets decreased, and the release mechanism gradually changed from diffusion to erosion. The dense cross-linkage between MD and KGM helped prevent tablet disintegration, and slowed down the release of IgY. In addition, the dissolved KGM formed a film on the tablet surface to control the erosion rate. It can be concluded that the optimal formulation of an IgY-loaded tablet was a mass fraction of 50% MD, 30% KGM, and 20% IgY. The present work provided a practical method to protect the biologically active ingredients from acidic destruction in the stomach during oral treatment. [ABSTRACT FROM AUTHOR]

Background and Objectives: Periodontitis is an inflammatory disease in the supporting tissues of the teeth caused by specific microorganisms or groups of microorganisms. P. gingivalis bacterium is the keystone pathogen in periodontitis, so even at low concentrations, it has a considerable influence on the oral community. Antimicrobials and antiplaque agents can be used as adjunctive therapy for periodontitis treatment. Konjac glucomannan (KGM), as a natural polysaccharide, has flavonoid (3,5-diacetyltambulin) and triterpenoids (ambylon) compounds that show antibacterial activity. This research aims to analyze the antibacterial activity of KGM on animal and in vitro periodontitis models. Materials and Methods: The animal study divided 48 mice into four groups (control, KGM, periodontitis, KGM + periodontitis). Mice were given an intervention substance by oral gavage from day 1 to day 14, periodontitis was induced on day 7, and decapitation was performed on day 14. Samples from the right maxillary jaw of mice were used for histological preparations and morphometrics analysis. In vitro studies were carried out by adding several concentrations of KGM (25, 50, and 100 μg/mL) into a planktonic P. gingivalis and P. gingivalis biofilm. Results: In the animal model, KGM could prevent alveolar bone loss in the periodontitis mice model, both in histologic and morphometrics assessments. In vitro, KGM had antibacterial activity against P. gingivalis with better bacteriostatic (15–23%) than bactericidal (11–20%) ability, proven by its ability to inhibit P. gingivalis proliferation. Conclusions: KGM can be considered to have the potential as an antibacterial agent to prevent periodontitis. The prevention of periodontitis may improve patient well-being and human quality of life. [ABSTRACT FROM AUTHOR]

Konjac glucomannan (KGM) is a promising bio-based material that can effectively mitigate the global petroleum-based plastic pollution exacerbated by the responses to COVID-19. This study first acidified KGM to obtain KGM microcrystals (MKGM) with a relatively low molecular mass. Next, different volumes of graphene oxide (GO) dispersions were mixed with MKGM to prepare composite films via physical cross-linking using glycerol as a plasticizer. The UV barrier capability, mechanical strength, thermal stability, and water resistance of these films were subsequently assessed. GO enhanced the tensile strength of the polysaccharide, while limiting its toughness. Thus, the tensile strength of the MKGM film improved from 7.80 MPa to 39.92 MPa following the addition of 12 mL of GO dispersion, and the elongation at break decreased from 46.31% to 19.2%. A morphological study revealed that the addition of different volumes of GO caused the composite films to exhibit various degrees of porosity and an enhanced water barrier capability. Introducing GO also improved the UV barrier capability and thermal stability of the composite film. Meanwhile, the composite films exhibited excellent degradation properties. Therefore, composite films prepared via the acidification of KGM and the incorporation of GO are suitable for extensive utilization in degradable plastics. [ABSTRACT FROM AUTHOR]

Common konjac flour, especially of low grade, is a waste material produced in large quantities during purification of konjac glucomannan (KGM). It contains impurities, particularly oxalate salts, which irritate and may cause kidney stones. Konjac flour has glucomannan as a main component. Glucomannan is characterized by low crystallinity, high thermostability, and the ability to form a strong gel. Subsequently, glucomannan has good potential for the production of biodegradable material. However, its high-water affinity limits its use in packaging. The deacetylated by thermal forming process and reinforced konjac flour with 15% and 20% of microcrystalline cellulose showed improved water absorption and thermal properties of the specimen. Moreover, the thermal forming process resulted in the reduction of soluble oxalate. Therefore, due to the conditions used in this experiment, the material will be stronger, more waterproof properties, and more highly resistant to temperatures, so it is suitable to be used as a packaging that is environmentally friendly. [ABSTRACT FROM AUTHOR]

Konjac glucomannan (KGM) is a high-molecular-weight polysaccharide that was originally extracted from the corms (underground storage organs) of Amorphophallus konjac. KGM and its oligomers have been reported as dietary fibers that exhibit an array of health benefits. The depolymerization of KGM via enzymatic hydrolysis at different conditions gives products of low viscosity and can be used for coating materials in microencapsulation. In the present study, konjac glucomannan hydrolysates (KGMHs) were produced by enzymatic hydrolysis using commercial mannanase at pH 4.5 at 70 °C for 5–120 min, then KGMHs' molecular weight (Mw), Degree of Polymerization (DP) and their bioactivities were determined. A longer hydrolysis time resulted in KGMH of a lower DP. Oligoglucomannans (Mw < 10,000) could be obtained after hydrolysis for 20 min. The DP of KGMH rapidly decreased during an early stage of the hydrolysis (first 40 min); DP reached around 7 at the end of the hydrolysis. Antioxidant activities were determined by the DPPH radical scavenging and FRAP assays of KGMHs prepared at pH 4.5 and evaluated at pH 2.0–8.0 depending on pH. KGMH having lower Mw exhibited higher antioxidant activities. KGMHs having the smallest molecular weight (Mw = 419) exhibited the highest DPPH radical scavenging activity. Mw and pH have a greater impact on KGMHs' bioactivities which can be useful information for KGMHs as functional ingredients. [ABSTRACT FROM AUTHOR]

The biomimetic scaffolds were fabricated using two natural biopolymers; Konjac glucomannan (KGM) and Silk fibroin (SF). The various proportions of KGM (1%) and SF (1%–2%) solutions were cross‐linked using citric acid as a cross linker and then lyophilized to prepare the fibrous scaffolds. The physicochemical properties of the KGM/SF scaffolds were investigated using FT‐IR analysis, TGA analysis, SEM, porosity, swelling, in vitro biodegradation, and mechanical characterization. FTIR spectra revealed the presence of characteristic functional moieties in the KGM/SF scaffolds. The improved thermal stability was observed for KGM/SF scaffolds compared to the control. The SEM images revealed that the scaffolds exhibited a porous morphology. The biodegradation of KGM/SF scaffolds was almost 77% until day 21, showing the biodegradable nature of the KGM/SF scaffolds. The compression strength of KGM/SF scaffolds was significantly higher than the KGM scaffold and eligible for soft tissue engineering. The KGM/SF scaffolds were further characterized by in vitro cell viability and cell attachment in fibroblast cells, demonstrating the non‐toxicity of scaffolds. Finally, in vivo CAM assay was successfully performed and determined the efficacy of KGM/SF scaffolds in vascularization. Overall, the results demonstrated that the KGM/SF scaffolds are biocompatible and capable of promoting vascularization in tissue engineering and biomedical applications. [ABSTRACT FROM AUTHOR]

In this study, a highly stable resistive switching behavior was obtained by utilizing konjac glucomannan, a biomaterial, as a dielectric layer through a solution-based process, and the ITO bottom electrode was modified by using an air plasma technique. Electrical results showed that the pretreatment device did not observe significant switching characteristics (∼101). The device, which underwent additional plasma treatment, was recognized for its significant improvements in this area, demonstrating a reduced set voltage (Vset = 0.37 V) with a 6% coefficient of variation, more than 200 consecutive cycles, and up to 90% electrical yield. Moreover, the treated device exhibited a dramatically higher memory window (>104) due to the relatively low off-state current. According to the XPS and UPS analysis, the work function increased from an untreated 4.3 to 5.79 eV as the treatment time increased to 180 s. The conductive filaments, which stemmed from oxygen vacancies, were introduced through plasma treatment to enhance the proportion of oxygen vacancies in the ITO films, thereby creating a stable and consistent filament path. Consequently, the systematic and reproducible resistive switching phenomenon was intensified. The reported results confirmed that the reliability and uniformity in bioelectronic devices can be accomplished through a simple and effective plasma technique. This approach paved the way for alternative applications of these devices. [ABSTRACT FROM AUTHOR]

BACKGROUND: The health of elderly individuals is closely linked to their protein intake and the abundance of intestinal microbiota. To investigate the impact of a compound powder made from mulberry leaf and konjac (hereinafter referred to as 'compound powder') on regulating the structure of intestinal microbiota in 15‐month‐old BALB/c mice that were fed a high‐beef‐protein diet, 16S rRNA high‐throughput sequencing, reverse transcription quantitative polymerase reaction, western blot, and other biochemical methods were used to analyze the differences in intestinal microbiota, protein metabolism‐related genes, short‐chain fatty acid (SCFA) content, and serum cytokines. RESULTS: The results showed that the compound powder increased the content of SCFAs, reduced the inflammatory reaction of the body, adjusted the abundance of intestinal microbiota (Firmicutes and Bacteroidetes), and increased the ratio of Firmicutes to Bacteroidetes (F/B). Moreover, the compound powder could increase the abundance of Lactobacillus and some non‐dominant bacteria that were related to amino acid metabolism and beneficial to human health, such as Eubacterium coprostanoligenes. These beneficial bacteria competitively reduced the abundance of harmful bacteria to protect the intestinal barrier and promote intestinal health, and upregulated the activities of aminopeptidase, proton‐coupled oligopeptide transporter 1, and glutamate dehydrogenase at the transcription and translation levels. CONCLUSION: The compound powder could balance the abundance of intestinal microbiota, which may improve the metabolic capacity of old mice on a high‐protein diet, and ultimately promoting the well‐being of elderly individuals. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In this study, the effects of konjac glucomannan (KGM) at different concentrations on the physiochemical and sensory properties of soy protein isolate (SPI), pea protein isolate (PPI), or peanut protein isolate (PNPI) compound gels were investigated. The results revealed that when the ratio of PNPI to KGM was 90:10, the denaturation temperature of PNPI could be significantly enhanced to 119.32°C by KGM modification. Concerning the textural and microstructural features, the amount of KGM addition had positive correlation with the hardness and chewiness of each compound gel, however, too much KGM addition will cause the unstable internal structure of the PNPI/KGM compound gels (70:30 and 60:40). Furthermore, sensory results indicated that PNPI/KGM (80:20), PPI/KGM (80:20), SPI/KGM (80:20) had great potential to be considered as prototypes for novel plant‐based products, which generated the highest acceptance scores of 5.04, 5.94, and 5.36 in each group, respectively. [ABSTRACT FROM AUTHOR]

BACKGROUND: The high viscosity of konjac glumannan (KGM) limits its application in meat processing. In this work, the effects of konjac oligo‐glucomannan (KOG), as a derivative of KGM, on the emulsifying properties of myofibrillar protein (MP) and the related mechanism were investigated. RESULTS: It was found that the addition of KOG had no significant effect on the secondary structure of MP, but altered the tertiary conformation of MP, resulting in exposure of tyrosine residues to polar microenvironments and decreased intrinsic fluorescence intensity. In addition, the addition of KOG increased the emulsifying activity of MP, resulting in decreased particle size and improved physical stability of the emulsion. The emulsifying activity of MP reached the maximum value when 1.0 wt% KOG was added. Moreover, the interfacial tension and interfacially adsorbed protein content of MP/KOG emulsions decreased with the increase in KOG concentration. CONCLUSION: These findings demonstrated that KOG mainly interacted with MP and changed the amphipathy of the KOG‐MP at the oil–water interface, forming a stable interface film to improve the emulsifying properties of MP. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Illumina high-throughput sequencing was used to explore the diversity and composition of the soil and root endosphere bacterial communities in three replanted konjac sites in 1-, 3-, and 5-year cropping systems. Continuous cropping of konjac caused a substantial decrease in soil pH and the activities of soil sucrase, urease, catalase, and alkaline phosphatase, and led to a remarkable and persistent decrease in the soil and root endosphere bacterial species abundance and alpha-diversity. Among the nine dominant bacterial phyla, Proteobacteria and Actinobacteria had the highest relative abundance, with averages of 61.3% and 11.2%, respectively. Several potentially beneficial genera, including Acinetobacter, Arthrobacter, and Pseudomonas, were less abundant in soil (84.6%, 82.7%, and 83.3%) and root (98.6%, 71.4%, and 98.1%) samples under 5 years of continuous cropping compared with those under 1-year cropping. Conversely, the potentially harmful genus Haliangium exhibited higher relative abundance in 5-year soil and root samples than in 1-year samples. Continuous cropping altered the bacterial community composition in the soil and root endosphere of konjac by influencing soil variables, leading to a reduction in the alpha-diversity of bacteria and the relative abundance of potentially beneficial bacteria, which in turn resulted in konjac poor growth in the continuous cropping system. [ABSTRACT FROM AUTHOR]

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Konjac glucomannan (KGM) and cassava acetylated distarch phosphate ( ADSP ) were used as raw materials, methyl cellulose as emulsifying agent, and soybean oil as oil phase to prepare KGM-ADSP composite emulsion gels. The effects of different freezing treatments on the texture, rheology and thermal properties of KGM- ADSP composite emulsion gels were studied by measuring the color, whiteness, centrifugal loss, ect. of KGM- ADSP composite emulsion gels after different freezing treatments and porcine back fat (control group). The results showed that freezing treatment could significantly improve the whiteness, hardness, elasticity and centrifugal loss of KGM-ADSP composite emulsion gels, and reduce the cooking loss, storage modulus and loss modulus, and no oil melting occurred in KGM-ADSP composite emulsion gels when heating up. The whiteness, texture, hardness, cohesion, chewiness and rheological properties of KGM-ADSP composite emulsion gels after 300 W ultrasonic- assisted freezing treatment were closest to those of porcine back fat. And the differences in storage modulus and loss modulus between KGM-ADSP composite emulsion gels after 300 W ultrasonic-assisted freezing treatment and pig back fat were minimal under certain thermal environment. It could be used as the fat mimetic in hot processed meat products. [ABSTRACT FROM AUTHOR]

Aims: To explore novel microbial endoglucanases with unique properties derived from extreme environments by using metagenomics approach. Methods and results: A Tibetan soil metagenomic library was applied for screening cellulase-active clones by function-based metagenomics. The candidate genes in the active clones were identified through bioinformatic analyses and heterologously expressed using an Escherichia coli system. The recombinant endoglucanases were purified and characterized using enzyme assays to determine their bioactivities, stabilities, substrate specificities, and other enzymatic properties. A novel endoglucanase gene Zfeg1907 was identified, which consisted of a glycoside hydrolase family 44 (GH44) catalytic domain along with a polycystic kidney disease (PKD) domain and a fibronectin type Ⅲ (Fn3) domain at the C terminal. Recombinant enzyme ZFEG1907 and its truncated mutant ZFEG1907t (ΔPKDΔFn3) were successfully expressed and purified. The two recombinants exhibited catalytic activities toward carboxymethyl cellulose, konjac glucomannan (KGM), and lichenan. Both enzymes had an optimal temperature of 50°C and an optimal pH value of 5.0. The catalytic activities of both recombinant enzymes were promoted by adding Zn2+ and Ca2+ at the final concentration of 10 mM. The Km value of ZFEG1907 was lower, while the kcat/Km value of ZFEG1907 was higher than those of of ZFEG1907t when using carboxymethyl cellulose, KGM, and lichenan as substrates. Structure prediction of two recombinants revealed that PKD-Fn3 domains consisted of a flexible linker and formed a β-sandwich structure. Conclusions: A novel endoglucanase ZFEG1907 contained a GH44 catalytic domain and a PKD-Fn3 domain was characterized. The PKD-Fn3 domains were not indispensable for the activity but contributed to the enzyme binding of the polysaccharide substrates as a carbohydrate-binding module (CBM). [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the investigations of various contents of egg white protein (2.0%–8.0%, EWP), microbial transglutaminase (0.1%–0.4%, MTGase), and konjac glucomannan (0.5%–2.0%, KGM) on the gelling properties and rheological behavior of Trachypenaeus Curvirostris shrimp surimi gel (SSG), and assessed the modification mechanisms through the analysis of structure characteristics. The findings suggested that all modified SSG samples (expect SSG‐KGM2.0%) had the higher gelling properties and the denser network structure than those of unmodified SSG. Meanwhile, EWP could give SSG a better appearance than MTGase and KGM. Rheological results showed that SSG‐EWP6% and SSG‐KGM1.0% had the highest G′ and G″, demonstrating that the formation of higher levels of elasticity and hardness. All modifications could increase gelation rates of SSG along with the reduction of G″ during the degeneration of protein. According to the FTIR results, three modification methods changed SSG protein conformation with the increasing α‐helix and β‐sheet contents and the decreasing of random coil content. LF‐NMR results indicated that more free water could be transformed into immobilized water in the modified SSG gels, which contributed to improve the gelling properties. Furthermore, molecular forces showed that EWP and KGM could further increase the hydrogen bonds and hydrophobic interaction in SSG gels, while MTGase could induce the formation of more disulfide bonds. Thus, compared with another two modifications, EWP modified SSG gels showed the highest gelling properties. [ABSTRACT FROM AUTHOR]

Combined with the Konjac transcriptome database of our laboratory and internal reference genes commonly used in plants, the eight candidate internal reference genes were screened and detected. They are the 25S ribosomal RNA gene (25S rRNA), 18S ribosomal RNA gene (18S rRNA), actin gene (ACT), glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH), ubiquitin gene (UBQ), β-tubulin gene (β-TUB), eukaryotic elongation factor 1-αgene(eEF-1α), and eukaryotic translation initiation factor 4α-1 gene (eIF-4α). The results of GeNorm, Normfinder, and BestKeeper were analyzed comprehensively. The data showed that the expression levels of 25S rRNA, 18S rRNA, and ACT at the reproductive periods, eEF-1α and eIF-4α at the nutritional periods, and eEF-1α, UBQ, and ACT at different leaf developmental periods were stable. These identified and stable internal reference genes will provide the basis for the subsequent molecular biology-related studies of Konjac. [ABSTRACT FROM AUTHOR]

The aim of this work was to study the physical stability and rheological properties of an oil-in-water emulsion stabilized by a konjac glucomannan–whey protein (KGM-WP) mixture at a konjac glucomannan concentration of 0.1–0.5% (w/w) and a whey protein concentration of 1.0–3.0% (w/w). The droplet size, microstructure, stackability, flow behavior, and viscoelastic properties were measured. The experimental results showed that with an increase in KGM and WP concentrations, the droplet size (D4,3) of the emulsion gradually decreased to 12.9 μm, and the macroscopic performance of the emulsion was a gel-like structure that can be inverted and resist flow and can also be extruded and stacked. The static shear viscosity and viscoelasticity generally increased with the increase of konjac glucomannan and whey protein concentration. Emulsions were pseudo-plastic fluids with shear thinning behavior (flow behavior index: 0.15 ≤ n ≤ 0.49) and exhibited viscoelastic behavior with a storage modulus (G′) greater than their loss modulus (G″), indicating that the samples all had gel-like behavior (0.10 < n′ < 0.22). Moreover, storage modulus and loss modulus of all samples increased with increasing KGM and WP concentrations. When the concentration of konjac glucomannan was 0.3% w/w, the emulsion had similar rheological behavior to commercial mayonnaise. These results suggested that the KGM-WP mixture can be used as an effective substitute for egg yolk to make a cholesterol-free mayonnaise-like emulsion. The knowledge obtained here had important implications for the application of protein–polysaccharide mixtures as emulsifiers/stabilizers to make mayonnaise-like emulsions in sauce and condiments. [ABSTRACT FROM AUTHOR]

Therapeutic strategies based on utilizing endogenous BMSCs have been developed for the regeneration of bone, cartilage, and ligaments. We previously found that E7 peptide (EPLQLKM) could enhance BMSC homing in bio-scaffolds and, therefore, promote cartilage regeneration. However, the profile and mechanisms of E7 peptide in cartilage regeneration remain elusive. In this study, we examined the effect of E7 peptide on the BMSC phenotype, including adhesion, viability and chondrogenic differentiation, and its underlying mechanism. The konjac glucomannan microsphere (KGM), a carrier material that is free of BMSC adhesion ability, was used as the solid base of E7 peptide to better explore the independent role of E7 peptide in BMSC behavior. The results showed that E7 peptide could support BMSC adhesion and viability in a comparable manner to RGD and promote superior chondrogenic differentiation to RGD. We examined differentially expressed genes of BMSCs induced by E7 compared to RGD. Subsequently, a real-time PCR validated the significantly upregulated expression of lncRNA H19, and the knockdown of lncRNA H19 or miR675, a downstream functional unit of H19, could significantly obscure the chondrogenic differentiation induced by E7. In conclusion, this study confirmed the independent role of E7 in the adhesion and viability of BMSCs and revealed the pro-chondrogenic effect of E7 on BMSCs via the H19/miR675 axis. These results could help establish new therapeutic strategies based on employing endogenous BMSCs for cartilage tissue regeneration. [ABSTRACT FROM AUTHOR]

The polished konjac flours were autoclaved (120℃, 30min.) or heated in boiling water (100℃, 30min.) at different moisture contents of 82.0-99.1%. After cooling, the ground samples were examined for MB staining. As a result, when the moisture contents were low (82.0 to 90.0%), the surface of the sample was seen to be stained light blue. On the other hand, in the case of high moisture contents (98.2, 99.1%), no blue-stained material was observed except for staining such as cell walls. From these results, it was confirmed that GM granules were stained with MB by heating under low moisture conditions in the case of polished flour. These results also suggest that the electrostatic properties of GM granules in raw konjac corms due to heating is related to the suppression of water supply necessary for sufficient swelling of GM granules in cells due to the toughness of the corm tissue, which is similar to the gelatinization of starch in the tissue of legumes. Although the details are unknown, it was speculated that the phase transition of GM molecules heated under low moisture is the cause of electrostatic properties. Viscosity was measured using RVA with a moisture content of 99.1%, and the presence or absence of MB staining was examined after the measurement was completed. As a result, MB staining of the sample was not observed regardless of the heating rate and final temperature. From this result, it was inferred that the electrostatic properties of GM granules observed in this study is not related to the exothermic phenomenon (phase transition) found by Karim et al. using differential scanning calorimetry (DSC) [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)