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Glucomannan/graphene oxide (GM/GO) hydrogel was synthesized by using calcium hydroxide as the crosslinker. The synthesized material was characterized by using IR, XRD, SEM, EDX and RAMAN technology. The composite hydrogel was used for removal of organic dyes from aqueous solution. The results showed that the GM/GO hydrogel had a porous structure and a high adsorption capacity toward methylene blue (MB). The pseudo-second-order kinetic model could fit the rate equation of MB adsorption onto the GM/GO hydrogel. The adsorption of MB onto GM/GO hydrogel was a spontaneous process. In addition, the equilibrium adsorption isotherm data indicated that equilibrium data were fitted to the Langmuir isotherm and the maximum dye adsorption capacity was 198,69 mg.g-1. Moreover, the hydrogel was stable and easily recovered and adsorption capacity was around 97% of the initial saturation adsorption capacity after being used five times.

Background Konjac glucomannan (KGM) is a functional polysaccharide isolated from the tubers of Amorphophallus konjac C. Koch known for its superior heat-set gel-forming capacity. Although commonly used for decades in food industry, KGM's unique gelling behavior has drawn lots of attention in recent years, and it also presents significant challenges especially when elucidating its gelation mechanism. Scope and approach In this review, recent progress and developments on gelation mechanism of the alkali induced heat-set KGM gel have been summarized on many key topics, including the experimental techniques, differences between gel preparation routes, and most importantly, correlating morphological/structural features and intermolecular interactions during the gelling process. In addition, impacts of internal and external factors on the KGM gelation, especially the mechanically related properties, have been also discussed. Key findings and conclusions The understanding of KGM gelation has been evolving over the last decade. The possible gelation includes the deacetylation induced by alkali addition, the stretch and physically association of chains upon heat-treatment, and the three-dimensional gel network established on the agglomeration of random network. Although insights have been provided into the gelation mechanism of KGM in this review which uncovers the foundational aspects of structure/property relationships in terms of KGM gel. There are still unanswered questions and areas, in particular the alkali and heat-treatment induced intermolecular association mechanism, where further research employing some state-of-the-art in situ characterization techniques as well as computation models is required.

Hydrogen generation through hydrolysis of sodium borohydride was examined over a series of supported cobalt nano particles as novel catalysts. For the first time extracted Glucomannan from Orchis Mascula used as a suitable matrix for preparation and stabilization of cobalt catalysts. Insoluble glucomannan obtained by polymerization reaction in the presence of MBA cross-linker and MAA monomer. Size, morphology and hydrogen generation activity of Co-glucomannan powders are studied by varying MAA/MBA ratios. XRD, XPS, FE-SEM and TEM techniques were used to characterization of obtained catalysts. All nano catalysts are formed in amorphous phase. Electron microscopic images confirmed that almost all particles are less than 10 nm. It is shown, cobalt particles are dispersed on the surface of glucomannan polymer without agglomeration. Catalytic activity of obtained Co-glucomannan are tested on hydrogen generation over hydrolysis of sodium borohydride reaction. Kinetic studies were applied to determine partial order respect to catalyst dosage and initial concentration of sodium borohydride. Finally, Arrhenius equation was used to find activation energy of hydrolysis sodium borohydride reaction over Co-glucomannan nano catalyst.

In this study, konjac glucomannan, κ‐carrageenan, and tannic acid were selected to study the effects of different combinations on the in vitro digestibility and physicochemical properties of wheat starch. Results showed that the addition of konjac glucomannan, κ‐carrageenan, and tannic acid could decrease the digestion of starch and increase the content of resistant starch. Besides, the two polysaccharides weakened the extent of tannic acid on starch digestion. Moreover, although the two polysaccharides had different effects on the in vitro digestion of starch, they had no significant increase in the content of resistant starch. DSC and XRD results demonstrated that the polysaccharides and tannic acid showed synergistic effects on the rebuilding of starch microstructure. FTIR results further manifested that κ‐carrageenan and konjac glucomannan could significantly increase the strength of hydrogen bonds in starch. At the same time, the addition of tannic acid would weaken the molecular interaction between polysaccharides and starch. SEM and CLSM results showed that tannic acid added to the polysaccharide–starch mixture not only interacted with starch but also influenced the structure of polysaccharide gel., Two dietary polysaccharides inhibited the direct contact of tannic acid with starch. Polysaccharides and tannic acid synergistically inhibited the formation of ordered starch structure. Tannic acid weakened the molecular interaction between the two polysaccharides and wheat starch.

Cellulose has been identified in fossil material, but the preservation potential of hemicelluloses, which are less resistant to decomposition than cellulose, is generally considered very low. Here we present the discovery of hemicellulose in Miocene xylites (fossil wood) and Cretaceous xylo-detritic coals from Poland. The main building blocks of hemicelluloses in softwood are mannose, glucose, xylose with lesser amounts of galactose and arabinose. These saccharides were detected in the coals and xylites using independent geochemical methods. Based on chemical analysis, the lignites contained significant holocellulose (22–37%), α-cellulose (8–29%) and hemicellulose (7–13%). In the smoke from a xylite burn test, levoglucosan and mannosan were dominant, the latter a specific hemicellulose alteration product. Glucose and mannose products dominated after methanolysis, with minor galactose and xylose. The main hemicellulosic polysaccharides in lignite appear to be glucomannan and/or galactoglucomannan but with a lower mannose content, possibly connected to wood degradation by fungi. The preservation of hemicelluloses in fossil material may be due to structural interconnection between lignin, cellulose and hemicellulose (i.e. lignocellulose), common in extant wood. This is the first documentation of hemicelluloses in fossil material. Our results show that not only cellulose, but also hemicelluloses can persist for millions of years under favorable conditions with only minor structural changes due to slow microbial and/or diagenetic decay. In fossil wood, types of hemicellulose can help assess whether the ancient plants were related to gymnosperms or angiosperms.

Carrageenan and konjac glucomannan are non-toxic polysaccharides which have been widely applied in the biomedical fields. Berberine as the antibacterial agent was successfully loaded into carrageenan/konjac glucomannan hydrogels. The Berberine loaded carrageenan/konjac glucomannan dried hydrogels display three-dimensional network structure, good swelling behavior and high porosity. These dried hydrogels also show controlled release behavior of Berberine. A good antibacterial effect towards S. aureus and C. albicans with good cell compatibility is exhibited. Thus, the fabricated Berberine loaded carrageenan/konjac glucomannan dried hydrogels could be considered as novel antibiotic alternative antibacterial materials.

Most commonly used wound dressings have severe problems, such as an inability to adapt to wound shape or a lack of antibacterial capacity, affecting their ability to meet the requirements of clinical applications. Here, a nanocomposite hydrogel (XKP) is developed by introducing polydopamine nanoparticles (PDA NPs) into a food gum matrix (XK, consisting of xanthan gum and konjac glucomannan, both FDA-approved food thickening agents) for skin wound healing. In this system, the embedded PDA NPs not only interact with the food gum matrix to form a hydrogel with excellent mechanical strength, but also act as photothermal transduction agents to convert near-infrared laser radiation to heat, thereby triggering bacterial death. Moreover, the XKP hydrogel has high elasticity and tunable water content, enabling it to adapt to the shape of the wound and insulate it, providing a moist environment suitable for healing. In-vivo skin wound healing results clearly demonstrate that XKP can significantly accelerate the healing of wounds by reducing the inflammatory response and promoting vascular reconstruction. In summary, this strategy provides a simple and practical method to overcome the drawbacks of traditional wound dressings, and provides further options when choosing suitable wound healing materials for clinical applications., Graphical abstract Image 1, Highlights • The nanocomposite hydrogel has excellent antibacterial activity and rapid shape adaptability. • The nanocomposite hydrogel possesses excellent blood compatibility and cytocompatibility. • The nanocomposite hydrogel varied with the shape of the wound when it was stretched or pressed. • The nanocomposite hydrogel can significantly improve the healing of bacteria-infected wounds.

Konjac glucomannan polysaccharide (KGM), inulin oligosaccharide (inulin) and their mixture has been shown to modulate the gut-associated lymphoid tissue immunity.The present study was mainly to determine effects of a low-level (2% w/w) KGM and inulin and their combination on dextran sodium sulfate (DSS)-induced colitis. We also determine the potential mechanisms mediating these effects of dietary fibers.C57BL/6J mice (6 weeks of age, eight per group) were randomly assigned to consume one of the following diets: control (DSS group) or control diet supplemented with 2% (w/w) of KGM (KGM group), 2% (w/w) of inulin oligosaccharide (inulin group) or KGM+Inulin (1%, w/w each (K+I group)) for 29 days, combined with the DSS drinking water (2% w/v) treatment on days 21-26. Another group served as vehicle was fed the control diet and given regular drinking water throughout the study. Fresh feces were collected on days 26-29. Mice were killed on day 30 after fasting. Segments of distal colon were processed for histological procedure. The remaining colonic tissues were processed to determine the colonic gene expressions of cytokines, tight junction proteins and antioxidant enzymes.The present study indicated that DSS resulted in colonic dysplasia, severe leukocyte infiltration and enhanced gene expressions of pro-inflammatory cytokines. All fiber treatments ameliorated these indices of colitis. DSS treatment reduced the colonic gene expressions of tight junction proteins and antioxidant enzymes, which were ameliorated or normalized with fiber supplementation. In addition, all fiber treatments prevented the DSS-induced alterations in the fecal microbiota and short-chain acid levels.Supplementation of low-level, 2% (w/w), of KGM polysaccharide, inulin oligosaccharide and K + I reduced the DSS-induced colitis and mucosal barrier dysfunction, which was likely to be mediated by the prebiotic effects.

Cell-wall polysaccharides are synthesized from nucleotide sugars by glycosyltransferases. However, in what way the level of nucleotide sugars affects the structure of the polysaccharides is not entirely clear. guanosine diphosphate (GDP)-mannose (GDP-Man) is one of the major nucleotide sugars in plants and serves as a substrate in the synthesis of mannan polysaccharides. GDP-Man is synthesized from mannose 1-phosphate and GTP by a GDP-Man pyrophosphorylase, VITAMIN C DEFECTIVE1 (VTC1), which is positively regulated by the interacting protein KONJAC1 (KJC1) in Arabidopsis. Since seed-coat mucilage can serve as a model of the plant cell wall, we examined the influence of vtc1 and kjc1 mutations on the synthesis of mucilage galactoglucomannan. Sugar composition analysis showed that mannose content in adherent mucilage of kjc1 and vtc1 mutants was only 42% and 11% of the wild-type, respectively, indicating a drastic decrease of galactoglucomannan. On the other hand, structural analysis based on specific oligosaccharides released by endo-β-1,4-mannanase indicated that galactoglucomannan had a patterned glucomannan backbone consisting of alternating residues of glucose and mannose and the frequency of α-galactosyl branches was also similar to the wild type structure. These results suggest that the structure of mucilage galactoglucomannan is mainly determined by properties of glycosyltransferases rather than the availability of nucleotide sugars.

To elucidate the effects of polysaccharides, cellulose, water-soluble xylan (WXY), galactoglucomannan (GGM) and xyloglucan (XG) on lignification in vitro, artificial polysaccharide matrices were prepared from a combination of cellulose and hemicelluloses, and dehydrogenation polymer (DHP) was synthesized from coniferyl alcohol in the presence of the matrices by using horseradish peroxidase (HRP). Prior to DHP formation, interactions between cellulose and hemicelluloses were investigated with equilibrium adsorptions of the hemicelluloses on bacterial cellulose (BC) films and with quartz crystal microbalance with dissipation technique (QCM-D) to determine their adsorption on cellulose nanofibers (CNFs). Both analyses showed that the order of adsorption amounts was XG > GGM > WXY. The QCM-D experiments also suggested that HRP strongly interacted with cellulose rather than hemicelluloses. The amount of DHP generated in the XG-BC matrix was the largest among the prepared matrices, and XG facilitated the formation of 5–5′ interunitary linkages. Thus, XG must be involved in the lignification in primary wood cell wall. On the other hand, the amount of DHP in the GGM-BC matrix was the smallest, indicating that GGM hampered lignification.

This study aimed to determine the best simplicia-solvent comparison to extract Konyak Glucomannan (KGM) flour from porang tubers (Amorphophallus muelleri Blume) that obtained from Klangon Village, Saradan District. Extraction was carried out by water solvent with solvent-simplicia comparison of 1: 100; 1: 200; 1: 300; 1,5: 100; 1,5: 200; and 1,5: 300. The extraction was carried out at a temperature of 45oC and 55oC for 60 minutes. The results showed that the extraction of Konjac Glucomannan (CGM) flour, was optimally extracted with a 1: 300 simplicia-solvent ratio at 55oC for 60 minutes.

Glucomannan is consisted of D-glucose and D-mannose with β-1.4 linkages. Poultry had no enzyme to digest β linkage so that porang (Amorphophallus onchophyllus) glucomannan could be a prebiotic candidate. The study purposed to determine the effect of porang glucomannan on caecum bacterial composition (similarity, diversity, grouping of bacteria) using Terminal Restriction Fragment Length Polymorphisms method and performance (body weight gain, feed intake, feed conversion ratio) of broiler chickens. One hundred and eighty unsexed day old chicks (DOC) were divided into 6 treat-ments and 3 replicates (10 birds each) using completely randomized design (CRD). The treatments were P0 (basal feed), P1 (basal feed + 0.05% porang glucomannan), P2 (basal feed + 0.1% porang glu-comannan), P3 (basal feed + 0.15% porang glucomannan), KJ (basal feed + 0.1% commercial konjac glucomannan), and KM (commercial feed). The results showed that caecal bacterial composition of porang glucomannan treatment had similarity with konjac glucomannan and basal feed. Diversity index and species number of porang glucomannan treatment was higher than konjac glucomannan. Gluco-mannan prebiotics had higher Lactobacillus while the lowest Clostridium was obtained in 0.1% porang glucomannan treatment. The inclusion of glucomannan prebiotics gave no negative effect on the per-formance of broilers.

BACKGROUND Starch retrogradation and moisture migration of boiled wheat noodles (BWNs) result in quality deterioration and short shelf life. The objective of this research was to investigate whether konjac glucomannan (KGM) could improve the quality of BWNs and further establish the shelf-life prediction model. RESULTS The moisture distribution, recrystallization, and thermal properties of BWNs during refrigerated or ambient temperature storage were determined. Low-field nuclear magnetic resonance data showed that KGM addition induced left-shifts of T21 and T22 values, indicating that KGM limited the mobility of bound and immobile water among noodle matrices. X-ray diffraction spectra revealed that KGM did not change the crystal patterns of BWNs but could inhibit the starch recrystallization after refrigerated storage. The Tp and ΔH values of retrograded samples notably (P

The structure of water'soluble gluco' and galactomannans (GlcMan and GalMan) isolated from the roots of several Eremurus'related plant species has been studied previously. This article characterizes polysaccharides and other extraction products from the root tubers of Eremurus hissaricus by Fourier' transform infrared (FTIR) spectroscopy using an attenuated total reflectance (ATR) accessory. Polysaccharide samples were purified from protein substances with the Sevage method and discoloured through a polyamide column. In the FTIR spectra, the main peaks attributed to asymmetric and symmetric stretching vibrations of CH2 of the pyranose ring (for GluMan - 2886, 1373, 1244 cm-1; for GalGluMan - 2923, 1370, 1238 cm-1) were enhanced by purification after removing bound protein impurities. The KnownitAll and IR-Pal 2 software applications were used to examine the spectra of a sample of purified GalGluMan in the studied polysaccharides. The results show that the intensity of the absorption maximum decreased at 1732 cm-1. At the same time, at 1552.92 cm-1, a new band appeared that refers to the valence vibrations of carboxyl (CO) or nitroso (NO) groups in the purified polysaccharide. This band appeared as a result of the Maillard reaction between the protein and the reducing end of the polysaccharide unit. The intensity of the bands in the 1238-1244 cm-1 region also decreased in the purified samples, which may be due to the elimination of a small fraction of protein. The use of FTIR spectroscopy allows the process of purifying watersoluble GluMan and acid-soluble polysaccharide of GalGluMan from acrylamide impurities to be characterized timely and accurately. Additionally, this method allows a comparative estimation of functional groups in polysaccharides of the root tubers of E. hissaricus.

The synthesis of galactoglucomannan sulfates using a sulfamic acid/urea mixture in 1,4-dioxane was studied for the first time. The effect of the galactoglucomannan sulfation time and temperature on the sulfur content in the galactoglucomannan sulfates was investigated. The introduction of sulfate groups into the galactoglucomannan structure was confirmed by the elemental analysis and Fourier transform infrared spectroscopy. The initial and sulfated galactoglucomannans were identified by X-ray diffraction, electron microscopy, and gel permeation chromatography. The thermal analysis has shown that sulfated galactoglucomannan, after the endothermic peak related to the moisture removal, yields a pronounced high-intensity exothermic peak with a maximum at 216 °C, and above 230 °C, the heat absorption effect (endothermic peak) characteristic of decomposition of the parent substance in the range of 230–335 °C is observed. According to the scanning electron microscopy data, the initial galactoglucomannan consists of irregular asymmetric particles with an average size from 400 to 900 µm, and the sulfated galactoglucomannan ammonium salt consists of particles 200–500 µm in size with different shapes. It was shown by gel permeation chromatography that, after the sulfation process, the main galactoglucomannan peak shifts toward higher molecular masses (from 24 to 26 kDa).

Obesity is often correlated with insulin resistance and diabetes. Obese people need to consume high fiber, high protein, low fat, and/or low calories food. In this report, the effect of the consumption of jelly containing porang glucomannan and inulin along with a low-calorie diet on the development of insulin resistance and fasting blood glucose (FBG) in obese adults were studied. A total of fifty-five volunteers of both sexes, aged 21 to 35 , were randomized to 3 groups: treatment 2 years, and body mass index (BMI) ≥23 kg/m group, placebo group, and control group (not given any jelly). All participants should consume 1500 kcal daily for the first 4 weeks and 1200 kcal/day for the next 4 weeks, including 2 cups of jelly (120 g per cup) per day. Jelly with porang glucomannan and inulin maintain a normal level of insulin resistance index of individuals with normal FBG and significantly suppress insulin resistance development in individuals with FBG above normal baseline. These results significantly correlate with the intake of fiber. The FBG was maintained under normal conditions in individuals with normal baseline and improved from diabetes to prediabetes category in individuals with above normal baseline.

Seed coat mucilages are mainly polysaccharides covering the outer layer of the seeds to facilitate seed hydration and germination, thereby improving seedling emergence and reducing seedling mortality. Four types of polysaccharides are found in mucilages including xylan, pectin, glucomannan, and cellulose. Recently, mucilages from flaxseed, yellow mustard seed, chia seed, and so on, have been used extensively in the areas of food, pharmaceutical, and cosmetics contributing to stability, texture, and appearance. This review, for the first time, addresses the similarities and differences in physicochemical properties, molecular structure, and functional/bioactive properties of mucilages among different sources; highlights their structure and function relationships; and systematically summarizes the related genetic information, aiming with the intent to explore the potential functions thereby extending their future industrial applications.

Injectable hydrogels have been widely studied for the use as scaffolds or as carriers of therapeutic agents including proteins, cells, drugs, and bioactive molecules in the disease treatment and the regeneration and repair of tissues. Collagen-based hydrogels and pectin that mimic the extracellular matrix are generally applied to maintain the balance between physical and biofunctional features. In this study, preparation and characterization of novel hydrogels based on oxidized-konjac glucomannan (OKG), collagen, and oxidized-pectin (OP) have been successfully developed. Fabricated hydrogels were evaluated for their morphological, degradation, thermal stability, and mechanical properties. The physicochemical properties of OKG/collagen hydrogels without pectin (HG) or with pectin (HGP) and oxidized-pectin (HGOP) were studied. The results presented that with the addition of the OP content, the hydrogels degradation behavior and mechanical properties were improved. In addition, HGOP hydrogels enhanced the cell proliferation without any cytotoxic effect on mouse embryonic fibroblast (NIH-3T3) cells. These achieved results suggested that the developed hydrogel could be a suitable candidate to be applied for tissue engineering scaffolds.

The effect of initial stages of pulping of spruce, resembling prehydrolysis and alkaline cooking was studied using CP/MAS 13C-NMR, X-ray scattering, FSP and carbohydrate composition in order to study the impact of the pre-treatments on the fiber wall nanostructure. Removal of fiber wall components, hemicellulose and lignin, increased the fiber wall porosity and induced cellulose fibril aggregation. The effect of temperature and pH in the treatment on cellulose fibril aggregate size appears to be secondary. It is the removal of hemicellulose that has a profound effect on the supramolecular structure of the cellulose fiber wall. As the amount of hemicellulose dissolved from wood increases, the fibril aggregate size determined by NMR increases as well, ranging from 16 to 28 nm. Specifically, a good correlation between the amount of glucomannan in the fiber wall and the fibril aggregate size is seen. The lower the amount of glucomannan, the larger the aggregate size. Glucomannan thus seems to prevent aggregation as it acts as a very efficient spacer between fibrils. Elemental fibril size determined by NMR, was quite similar for all samples, ranging from 3.6 to 4.1 nm. By combining measurement methods, a more well-resolved picture of the structural changes occurring during was obtained.

The land plants evolved from a salt-water algal ancestor, diversifying on land into fresh-water algae, mosses, ferns, gymnosperms, and finally the angiosperms that dominate land today. In this study, the structures of high-molar-mass fractions in holocelluloses prepared from chara (a freshwater alga), haircap moss, adiantum, ginkgo, Japanese cedar, and eucalyptus were investigated using size-exclusion chromatography with multi-angle laser-light scattering, ultraviolet, and refractive index detection (SEC/MALLS/UV/RI). 4% NaOH-extracted holocelluloses prepared from the above algal and land plants were dissolved in 8% (w/w) lithium chloride/N,N-dimethylacetamide and subjected to SEC/MALLS/UV/RI analysis. The neutral sugar compositions of the samples were also measured. The holocelluloses prepared from chara, haircap moss, and adiantum had the same crystalline microfibril structures (~ 3 nm in width) as those prepared from ginkgo, Japanese cedar, and eucalyptus. However, SEC/MALLS/UV/RI analysis gave different results among samples. Haircap moss, adiantum, Japanese cedar, and ginkgo had cellulose/glucomannan branched structures linked through degraded fragments of residual lignin or lignin-like phenolic compounds. In contrast, 4% NaOH-extracted chara holocellulose had no such branched structures, but contained the same linear structure as found in eucalyptus. The results obtained in this study, therefore, showed the possibility that land plant cellulose fibers, have branched structures with glucomannan in the HMM fractions, even though the cellulose fibers are prepared by repeated delignification and successive 4% NaOH extraction.

This study aimed at investigating the effects of polishing conditions on the physicochemical properties of polished yellow konjac flour (PYKF) with a centrifugal mill using Central Composite Design-Response Surface Methodology (CCD-RSM). Micro-mill milled yellow konjac flour (MMYKF) mass and polishing cycles were the independent variables, with four observed responses (calcium oxalate, viscosity, degree of whiteness (DoW), and glucomannan). The lower limit (-1) and upper limit (+1) for MMYKF mass in this study are 10 and 15 kg, respectively, while the -1 and +1 for the polishing cycle are three times, and seven times, respectively. The optimum prediction occurred at 10 kg of MMYKF mass and six times the polishing cycle with the following characteristics: 0.52 ±0.00% w.b. calcium oxalate, 20362.00 ±16.00 cP viscosity, 62.22 ±0.01 DoW, and 69.43 ±0.02% d.b. glucomannan content, which agreed with the verification data with p-value >0.05 for all observed responses using the paired T-test. Polishing using a centrifugal mill is feasible and promises to be scaled up to industrial scale for yellow konjac flour polishing before the wet extraction process.

A pH-sensitive food packaging film was prepared based on konjac glucomannan (KGM) and hydroxypropyl methyl cellulose (HPMC) incorporated with mulberry extracts 2 (MBE). FT-IR and XRD analysis revealed that there are good molecular interactions among the three components. The incorporation of MBE into KGM and HPMC (KH) films can significantly improve the mechanical properties and UV resistance. Notably, the KH-MBE-20% film almost completely blocked UV light in the range of 200–600 nm. The best antioxidant and antibacterial properties were obtained when the addition of MBE in the composite film was 20%. In addition, KH-MBE film has good responsiveness to buffers with pH range from 2 to 12. In visual monitoring experiments using the film on fresh fish, the color of the KH-MBE film changed from purple to gray to yellow as the freshness of the fish decreased, and the KH-MBE-20% film had the best color stability. Therefore, intelligent packaging of KH-MBE film has potential applications in real-time monitoring of fish freshness.

Indonesian konjac (IK in brief), also known as Amorphophallus muelleri Blume in Latin, is a wild plant growing in several places in Indonesian archipelago. The tuber of IK plant contains a compound called glucomannan which has high economic value since it can be used as a raw material in many industries such as medicine, cosmetic, paper, textile, synthetic rubber, and filming industries. Due to this economic value, this study was carried out in order to increase the productivity of glucomannan and bring IK into mass cultivation. For this purpose, the objective of this study is to increase the productivity of IK tubers by increasing the speed of seeds gemination process and by decreasing the dormancy period. Meanwhile, bringing IK into mass plantation will be put as a package of campaign program to educate people. To speed up the germination process and to decrease the dormancy, the method used in this study period is by improving the soaking process of IK seeds using KNO3 solution. Its effects were investigated using a completely randomized design (CRD) with three treatments, namely, concentration of the solution, soaking time, and plant age. Then, data were collected and analyzed statistically using general linear model, analysis of variance and Duncan's multiple range test. The results indicate that soaking in that solution has a significant effect on shortening the time period for seeds to germinate. Its optimal effect was reached for 3,000 ppm of concentration with soaking time 3 hours at 14th days after plantation (DAP). Moreover, in terms of dormancy period, that solution has reduced from 5-6 months to 2-4 months. These findings were significantly support the effective use of KNO3 solution to answer the objective of research. The germination period has been reduced from 3-6 months to around 14 days. To the knowledge of the authors, based on the literature used in this study, these are unprecedented findings. Therefore, hopefully, it could contribute to the development of konjac-based industries and to the literature of konjac particularly Indonesian konjac.

The production, characterization and bioactivities of exopolysaccharides (EPSs) from a thermophilic bacterium Geobacillus sp. strain WSUCF1 were investigated. Using glucose as a carbon source 525.7 mg/L of exoproduct were produced in a 40-L bioreactor at 60 °C. Two purified EPSs were obtained: EPS-1 was a glucomannan containing mannose and glucose in a molar ratio of 1:0.21, while EPS-2 was composed of mannan only. The molecular weights of both EPSs were estimated to be approximately 1000 kDa, their FTIR and NMR spectra indicated the presence of α-type glycosidic bonds in a linear structure, and XRD analysis indicated a low degree of crystallinity of 0.11 (EPS-1) and 0.27 (EPS-2). EPS-1 and EPS-2 demonstrated high degradation temperatures of 319 °C and 314 °C, respectively, and non-cytotoxicity to HEK-293 cells at 2 and 3 mg/mL, respectively. In addition, both showed antioxidant activities. EPSs from strain WSUCF1 may expand the applications of microorganisms isolated from extreme environments and provide a valuable resource for exploitation in biomedical fields such as drug delivery carriers.

Carboxymethyl konjac glucomannan (CMKGM) is an anionic derivative of konjac glucomannan (KGM). Its coacervation with ovalbumin (OVA) was investigated through turbidity and coacervate yield measurem...

The pore size distribution of konjac glucomannan (KGM)-based aerogels seriously impacted the air filtration efficiency and filtration resistance. This study aimed to investigate the pore size distribution control of KGM-based aerogels through total solid concentration of the sol and to improve the filtration performance by preparing aerogel stacks, which were made by combining KGM-based aerogels with different pore size distribution (range: 0–180 μm). Results indicated that with increased total solid concentration from 50% to 100% of the origin formulae, aerogel pore size became smaller and the porosity was decreased for all the three sample formulae. Meanwhile, the aerogel mechanical property and filtration efficiency were both strengthened with increased total solid concentration, but the air resistance became significantly higher. The changing extent and rule were influenced by the sample components (KGM, starch, gelatin, wheat straw). The aerogel stacks prepared by in series combining the aerogel pieces with different pore size distribution (from large size to small size) was found to improve filtration efficiency (e.g. from 70% to 80% for K1G2S4WS2) and significantly lower the air resistance (e.g. from 270 Pa to 190 Pa for K1G2S4WS2). This study could guide the filtration performance improvement of aerogels.

Konjac tofu is a traditional Chinese food whose main ingredient is the water-soluble polysaccharide from konjac tubers-konjac glucomannan (KGM). Herein we report an interpenetrating double network polymeric film by crosslinking KGM and polyvinyl alcohol (PVA) with glutaraldehyde under acidic conditions. PVA was introduced into the hydrogel system as a hard skeleton, which not only maintained the biocompatibility of KGM, but also gave the hydrogel superior mechanical properties and solvent resistance. Implanting a colloidal array inside the above film, we obtained a new type of biomass based photonic crystal that is sensitive to a variety of physical and chemical stimulus, especially for methanol. This photonic crystal responds to methanol and methanol vapor, and has the ability to detect methanol in gasoline, which has a good application prospect.

The adsorption of Cu(II), Cd(II), and Pb(II) ions onto hydrogels derived from modified galactoglucomannan (GGM) hemicellulose was studied. GGM hemicellulose was modified with methacrylate groups (GGM-MA) to incorporate vinyl groups into the polymeric structure, which reacted later with synthetic monomers such as 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). The results show that all the synthesized hydrogels were capable of adsorbing contaminating ions with high adsorption efficiency during short periods of time. Furthermore, an increase in the content of GGM-MA generated a hydrogel (H3) with a similar ion adsorption property to the other hydrogels but with a lesser degree of swelling. The H3 hydrogel had an adsorption capacity of 60.0 mg g−1 Cd(II), 78.9 mg g−1 Cu(II), and 174.9 mg g−1 Pb(II) at 25 °C. This result shows that modified GGM hemicelluloses can be employed as renewable adsorbents to remove Cu(II), Cd(II), and Pb(II) ions from aqueous solutions.

The impact of preparation conditions including heating temperature (from 60 °C to 90 °C) and drying temperatures (from 25 °C to 90 °C) on the properties of pure curdlan film and konjac glucomannan (KGM) and curdlan blend films were analyzed. Microstructure analysis indicated the KGM addition could significantly improve the relatively poor film-forming property of curdlan. FTIR and X-ray analysis showed that at high heating temperature 90 °C, molecular interaction might be enhanced in the films due to the stretched structure of curdlan and dissociation of curdlan bundles or triple-helix structure. This was supported by the changes in the mechanical property, surface hydrophobicity, moisture barrier, and moisture tolerance property. The impacts of drying temperature were some different for the curdlan film and KGM/curdlan blend film, and were explained from the molecular hydrophilicity-hydrophobicity, compactness of the films, curdlan conformation, and molecular interaction. This work guided biodegradable film production especially with curdlan added.

The thermal reactivities of cellulose and hemicellulose are significantly different in cell walls when compared with isolated components and differ in Japanese cedar (softwood) and Japanese beech (hardwood). Uronic acid bound to xylan promotes the thermal degradation of cellulose and hemicellulose, and its effect is different depending on the form of free acid (acting as an acid catalyst) or metal uronate (acting as a base catalyst). We evaluated the location of uronic acid in the cell wall by identifying the components affected by demineralization in pyrolysis of cedar and beech wood. The thermal reactivities of xylan and glucomannan in beech were changed by demineralization, but in cedar, glucomannan and cellulose reactivities were changed. Therefore, the location of uronic acid in the cell wall was established and differed between cedar and beech; close to glucomannan and xylan in beech, but close to glucomannan and cellulose in cedar. Such information is important for understanding the ultrastructure and pyrolysis behavior of softwood and hardwood cell walls.

Barks of trees of the genus Handroanthus are known for their antitumor activity, which is attributed to naphthoquinones. Another class of molecules that has shown antitumor activity are the polysaccharides, however those from Handroanthus barks have never been studied. Accordingly, the aim of this study was to extract polysaccharides from H. heptaphyllus and H. albus barks, to characterize them structurally and to evaluate their cytotoxic effects on the human colon and human breast cancer cell lines, Caco-2 and MCF-7, respectively. The polysaccharides were extracted with boiling water and fractionated by freeze-thawing process. The soluble polysaccharide fractions HHBSF and HABSF were characterized by monosaccharide composition, methylation and NMR analyses, and their effects on proliferation of Caco-2 and MCF-7 cells were evaluated using MTT cell viability assay. HHBSF and HABSF were mainly constituted of galactoglucomannan, type II arabinogalactan (AGII) and type I rhamnogalacturonan (RGI), however, only HABSF significantly inhibited the growth of MCF-7 (CC50 = 327 μg/mL) and Caco-2 (CC50 = 2258 μg/mL) cells. Differences in the fine structure and proportion of their polysaccharides, and maybe in the composition of associated phenolic compounds could explain the different effects of HHBSF and HABSF.

P orang tuber is rich of glucomannan content but contained irritable compounds to be consumed. Ultrasound-assisted extraction (UAE) using isoprophyl alcohol (IPA) was developed as a purification method for glucomannan. This study aimed to determine the effects of UAE conditions (IPA concentration s , ratios of solvent - solid, and number of extraction stages) on the characteristics of purified glucomannan (PG) from porang flour (PF). Single-stage UAE using 80% IPA concentration and ratio of solvent - solid o f 8:1 (ml/g) for 10 min gave the highest glucomannan content (76.10%). At this condition, the PG visco s ity and yield were 12,800 cP and 96.1 0 % , respectively. Furthermore, the three-stage UAE using 80% IPA concentration in each stage improved the glucomannan content to 83.26% with 15,960 cP and 90.02% of yield. The morphology showed that the purified glucomannan powder s had smoother surface and less crump after the purification. Both carbonyl and acetyl group s were observed on PF and PG in different intensities. Keywords: glucomannan, isopropanol, Amorphophallus oncophyllus, ultrasound-assisted extraction

In this study, cellulose nanofibers (CNFs) from softwood and hardwood kraft pulps were prepared with different hemicellulose contents, and the effects of the hemicellulose compositions and contents on the interaction between CNFs were studied. In addition, the effects of CNF interaction on the CNF dispersion stability and viscosity characteristics in the aqueous state were investigated. Using quartz crystal microbalance with dissipation, the results of the interaction analysis revealed that hemicellulose moderated the strength of the interaction between CNFs, and the intensity of the interaction changed according to the hemicellulose compositions. The interaction between galactoglucomannans was stronger than that between glucuronoxylans, and CNFs prepared from softwood pulp containing mainly galactoglucomannan showed stronger interaction between CNFs than those prepared from hardwood pulp containing mainly glucuronoxylan. The presence of hemicelluloses on the surface of CNFs improved the dispersion stability and increased the viscosity. However, the intensity of the interaction between CNFs, which is dependent on the type of hemicellulose, did not affect these properties. The properties of CNFs in the aqueous state are determined by not only the interaction between CNFs but also several factors such as the morphology of CNFs and physical properties of hemicelluloses.

Encapsulation is a promising method for preventing the interaction of an active agent with the environment. Efficacious encapsulation relies on the compatibility of the active compound and the encapsulant. As an active agent, vitamin C is easily degraded due to oxidation, high temperature, and other extreme environmental conditions, hence it requires protection. Glucomannan has the potential to provide vitamin C matrix encapsulation. However, the glucomannan needs to be modified to optimize its compatibility with vitamin C. In this research, glucomannan was modified using Na2CO3. This study aimed to determine the impact of the deacetylation process in encapsulating vitamin C using a gelation method. The loading capacity of vitamin C was in line with the degree of deacetylation. The highest degree of deacetylation (87.95%) allowed loading 84.9% of vitamin C. The functional groups, morphological surface, and particle distribution were modified due to the deacetylation and encapsulation processes. Release of vitamin C from deacetylated glucomannan was determined in two pH solutions, i.e., pH 1.2 and 6.8 solutions. The Korsmeyer–Peppas model was fitted to the release of vitamin C from deacetylated glucomannan at pH 1.2 (R2 > 0.892) and at pH 6.8 (R2 > 0.772). This study suggested the strong potential of deacetylated glucomannan as an encapsulating agent for vitamin C using a gelation method.