Konjac Glucomannan Content Research Articles

Improved gel properties of Nemipterus virgatus myofibrillar protein emulsion gel by Konjac glucomannan incorporation: Insight into the modification of protein conformation

This study aimed to improve the gel properties of emulsion gels prepared by physical complex of fish protein and polysaccharide. The effects of Konjac glucomannan (KGM) on the structure, emulsibility of Nemipterus virgatus myofibrillar protein (MP), and the gel properties of heat-induced MP emulsion gel were investigated. The results indicated KGM modification facilitated the unfolding of MP, exposing more tryptophan and hydrophobic groups, thereby improving the wettability and emulsifying activity of MP/KGM mixtures. The interactions between MP and KGM molecules were mainly non-covalent hydrogen bonding and hydrophobic interaction. The MP/KGM mixtures exhibited superior adsorption properties at the oil-water interface, particularly with 0.5 % KGM addition, thus forming small and evenly distributed oil droplets. Besides, the curves of viscosity, G' and G" of MP/KGM emulsions climbed continuously with the increased KGM concentration. The presence of KGM, especially the medium amount (0.5 %), was conducive to the translation of α-helix into β-sheet and the formation of more dense and ordered gel network structure, thereby enhancing the gel properties of MP/KGM emulsion gels.

Improvement in Taste Quality of Rice Porridge Using Konjac Glucomannan.

Improving the taste quality of rice porridge in a scientific way is essential to guiding residential and commercial production. This study aimed to determine the impact of konjac glucomannan (KGM) on the taste quality of rice porridge. The obtained results showed that the optimal concentration of KGM added to rice porridge is 1%. This was primarily observed via the reduction in water absorption, swelling power, and iodine blue value, thus increasing the hardness of rice porridge. At the same time, KGM also reduced the free water content and improved the water-holding capacity of rice porridge. Nevertheless, the pasting properties showed that the high viscosity of KGM raised the pasting viscosity of rice flour, thereby enhancing the stickiness of rice porridge with the increase in the KGM concentration. In addition, KGM gave the rice porridge a stronger aroma. Sensory evaluations further confirmed significant improvements in the color, odor, palatability, and overall acceptability of KGM-supplemented rice porridge (p < 0.05). To summarize, adding an appropriate amount of KGM was beneficial in forming a richer flavor and improving the taste quality of rice porridge. The findings offer valuable insights into the scientific processing of rice porridge products.

Enzymatic hydrolysis and biological activities of Konjac glucomannan hydrolysate in different degree of polymerisation

SummaryThe study explores the enhanced functional and bioactive properties of Konjac Glucomannan Hydrolysate (KGMH) by partially degrading Konjac Glucomannan (KGM) using β‐mannanase over 60 min. KGM concentrations (40% and 50% w/w) were treated with 200–300 U g−1 of the enzyme over 60 min. The hydrolysis of KGM was monitored by colorimetry, with DP values ranging from 4.20 to 6.16 for 40% KGM and 4.10 to 4.60 for 50% KGM. MALDI‐TOF‐MS analysis confirmed typical oligosaccharides with DP values from 2 to 9 and some acetyl substitutions. The optimal conditions of 40% KGM with 250 U g−1 enzyme and varying hydrolysis times produced KGMHs with a wide range of DPs, demonstrating in vitro antioxidant and anti‐glycation activities. The results showed significant bioactivities (P &lt; 0.05) positively correlated with lower DP values. This study emphasises the potential of KGMH as a novel functional food ingredient, highlighting its bioactive properties and the significant impact of DPs on the biological functionality of saccharides.

Impact of lecithin on the lubrication properties of konjac glucomannan gels

The effects of lecithin addition on the properties of konjac glucomannan (KGM) hydrogels prepared by controlled heating were investigated. Weak hydrogels were formed at 1 % KGM, which contained relatively thick strands. The shear viscosity and shear modulus of the hydrogels increased with increasing KGM concentration. The pure KGM hydrogels exhibited relatively poor boundary lubrication at all polysaccharide concentrations studied. The inclusion of lecithin (0.001 % to 0.20 %) in the KGM hydrogels appreciably altered their rheological properties, which could be modulated by varying the lecithin/KGM ratio. Microstructural analysis showed that lecithin caused a substantial restructuring of the strands in the hydrogel network. Lecithin was also found to be a highly effective lubricant in the KGM hydrogels. Incorporation of trace amounts of lecithin led to a significant improvement in the lubricating properties of the KGM hydrogels, especially boundary lubrication. Fourier transform infrared (FTIR) and differential canning calorimetry (DSC) analyses provided information about the molecular interactions between the lecithin and KGM molecules. The ability of lecithin to increase the lubricating performance of the KGM hydrogels was mainly attributed to the adsorption of phospholipid-biopolymer complexes onto solid surfaces, which reduced the friction between them.

The effect of gelatin and konjac glucomannan concentrations on moisture content, water activity, texture, density, and protein content in synbiotic marshmallows

The effect of gelatin and konjac glucomannan concentrations on moisture content, water activity, texture, density, and protein content in synbiotic marshmallows

Mechanism for the synergistic gelation of konjac glucomannan and κ-carrageenan

The synergistic interaction gels (SIGs) can be created by blending konjac glucomannan (KGM) and κ-carrageenan, and have been applied to modify and improve the rheological and texture properties of food system. However, the assembly behaviors between them are still unclear. This work revealed that the presence of KGM promoted phase transition of nearby κ-carrageenan molecules probably by contributing to entropy increment. Subsequently, the rest of κ-carrageenan transformed into helical structure, assembled into a series of laterally arranged trigonal units and formed a three-dimensional network. In KGM/κ-carrageenan SIGs, the size of high density domains (Ξ) in aggregates and the distance of these high density domains (ξ) were narrowed firstly and then enlarged as increasing of KGM content. These nano-scale structure features were responsible for the relative higher gel strength for KGM/κ-carrageenan SIGs with proportion ratios of 1:9 (K1C9) and 3:7 (K3C7). This study serves to facilitate the design and production of SIGs with the requisite performance characteristics.

Construction of highly stable Pickering emulsion systems based on konjac glucomannan and xanthan gum/lysozyme nanoparticles under pasteurization

Pasteurization, as a meaningful part of food processing, has received growing attention for regulating Pickering emulsion stability. In this research, the role of pasteurization and konjac glucomannan (KGM) in the modulation of Pickering emulsion properties was investigated. The results showed that the network structure formed by KGM inhibited the agglomeration of droplets due to pasteurization, which improved the heat stability of the Pickering emulsion. Increasing the concentration of KGM improved the densification of its network structure, as evidenced by the enhanced viscoelasticity of the emulsion after pasteurization. The retention rate of β-carotene encapsulated in the Pickering emulsion could reach 99% after pasteurization at 65 °C for 30 min. Moreover, pasteurization further enhanced the inhibitory effect of KGM on free fatty acid release and implemented a manageable release of β-carotene. This research offers theoretical guidance for the construction of highly stable Pickering emulsions for delivering temperature-sensitive hydrophobic ingredients.

Investigation into the fabrication of plant-based simulant connective tissue utilizing algae polysaccharide-derived hydrogel

Connective tissue is an important component of meat products that provides support to animal muscles. Hydrogels are considered a promising alternative to connective tissues and simulate actual products by adjusting the gel texture and mouthfeel. This study used soybean protein isolate (SPI), corn starch (CS), konjac glucomannan (KGM), and seaweed powder (SP) as raw materials to examine the effect of different added SP and KGM concentrations on the gel texture. The G' of the gel increased five-fold when the SP and KGM concentration was increased from 1 % to 3 %. The results of mechanical property tests showed that with the addition of SP, the gel hardness increased from 316.00 g to 1827.23 g and the tensile strength increased from 0.027 MPa to 0.089 MPa. Sensory evaluation showed that the samples with 2 % SP and KGM presented the highest overall acceptability score and the most significant similarity to real connective tissue. The connective tissue simulants exhibited excellent water-holding capacity (>90 %), significantly increasing their juiciness. SEM indicated that 2 % KGM addition improved gel network structure stability. The results demonstrate the potential of seaweed polysaccharide-derived hydrogels as connective tissue mimics. This provides a new strategy for the preparation of high mechanical strength hydrogels and lays the foundation for structural diversification of plant-based meat.

Konjac glucomannan-fibrin composite hydrogel as a model for ideal scaffolds for cell-culture meat

In this study, composite gel was prepared from konjac glucomannan (KGM) and fibrin (FN). Composite gels with different concentration ratios were compared in terms of their mechanical properties, rheological properties, water retention, degradation rate, microstructure and biocompatibility. The results showed that the composite gels had better gel strength and other properties than non-composite gels. In particular, composite hydrogels with low Young's modulus formed when the KGM concentration was 0.8% and the FN concentration was 1.2%. The two components were cross linked through hydrogen-bond interaction, which formed a more stable gel structure with excellent water retention and in-vitro degradation rates, which were conducive to myogenic differentiation of ectomesenchymal stem cells (EMSCs). KGM-FN composite gel was applied to the preparation of cell-culture meat, which had similar texture properties and main nutrients to animal meat as well as higher content of dry base protein and dry base carbohydrate.

An engineering approach to the 3D printing of K‐Carrageenan/konjac glucomannan hydrogels

SummaryAqueous solutions of Konjac glucomannan (KGM)/κ‐Carrageenan (κ‐C) of different ratios (1:2, 1:5, 1:8 and 1:10) and a fixed κ‐C content of 1.5%, were proposed as a new 3D food printing ink. Their thermo‐responsive behaviour was evaluated by temperature ramp rheological tests. This characterisation allowed for the evaluation of the synergistic effect between KGM and κ‐C and gave indications useful to the printing performance. Both elastic (G′) and loss (G″) moduli were found to increase by increasing the KGM concentration. Samples were printed by controlling the thermally reversible sol/gel transition occurring during the process. Direct pressure and flow rate measurements in the 3D printer were used to obtain the viscosity versus shear rate curves under processing conditions, useful to validate a scaling law relating the printing filament diameter to the relevant process and material properties (inks viscosity and printing pressure). The 3D printing performance of inks was evaluated by means of a novel, integrated score system. The results obtained indicate that aqueous mixtures of KGM/κ‐C can be successfully employed as a base for 3D printing food hydrogels. The use of the score system above outlined proved to be an easy yet efficient tool for the optimisation of the gel composition.

Pickering emulsion with high freeze-thaw stability stabilized by xanthan gum/lysozyme nanoparticles and konjac glucomannan

In this study, freeze-thaw cycle experiments were conducted on food-grade Pickering emulsions co-stabilized with konjac glucomannan (KGM) and xanthan gum/lysozyme nanoparticles (XG/Ly NPs). The rheological properties, particle size, flocculation degree (FD), coalescence degree (CD), centrifugal stability, Differential scanning calorimetry (DSC), X-ray diffraction (XRD) and microstructure of Pickering emulsion stabilized by KGM before and after freeze-thaw were characterized. It was found that as the concentration of KGM increased, the flocculation degree (FD) and coalescence degree (CD) of the emulsion decreased after the freeze-thaw cycle compared to the control sample, and the microscopic images showed that the droplets became smaller and less affected by the freeze-thaw cycles. The rheological and water-holding properties also confirmed that the KGM-added emulsions still had a strong gel network structure and prevented the separation of the continuous and dispersed phases of the droplets after freezing and thawing. Freeze-thaw treatments had a negative effect on the stable emulsion of XG/Ly NPs, while the addition of KGM improved the freeze-thaw stability of the emulsion, which provided a theoretical basis for the development of emulsion products with high freeze-thaw stability.

Silk nanofibrous scaffolds assembled by natural polysaccharide konjac glucomannan

AbstractNatural 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.

Exploring the Antibacterial Potential of Konjac Glucomannan in Periodontitis: Animal and In Vitro Studies.

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.

Effect of blending ratio on the compatibility and stability of konjac glucomannan/starch composite systems

A series of complex dispersions and films combining Konjac glucomannan (KGM) and starch in different ratios were prepared. The compatibility and stability of KGM/Starch composite (KS) systems were evaluated using a new horizontal casting device coupled with CCD camera system and Near-infrared (NIR) spectrometer and multiple conventional characterization techniques. The findings from the casting device revealed that when the KGM and starch were combined in a 7∶3 ratio, the dispersion demonstrated isotropic behavior, flowing and diffusing at a consistent speed from the central point to the surrounding area on the casting disc. Additionally, the scattered particles in the NIR reflectance spectrum were evenly distributed at every point, indicating excellent compatibility and uniformity within the dispersion. FTIR and XRD analyses indicated the existence of molecular interactions between the film components, and showed good compatibility between KGM and starch when the KGM content was greater than 50%. The best compatibility was obtained when the KGM content was 70%. The SEM results showed that the increase of KGM content contributed to a smoother and denser microstructure in the cross-section of the KS composite films, especially when the KGM content was 70% (w/w). The rheological results of the KS dispersion further confirmed the formation of a hybrid network structure between KGM and starch. Higher KGM content led to more hydrogen bonds and provided more opportunities for macromolecular chain entanglement. This work will contribute to a better understanding of the interaction mechanism between polysaccharides and starch, as well as provide a new perspective and novel characterization methods to deconstruct the compatibility and assembly structure stability between KGM and starch. It is beneficial for facilitate the application of KGM in the development of denatured food or starch materials, including food texture properties and emulsion stability, and establish a foundation for the diversification of food design tools.

Construction of astaxanthin loaded Pickering emulsions gel stabilized by xanthan gum/lysozyme nanoparticles with konjac glucomannan from structure, protection and gastrointestinal digestion perspective

Pickering emulsion gels have demonstrated their efficacy in delivering bioactive compounds by effectively preventing droplet aggregation, Ostwald maturation, and phase separation through gel network. Astaxanthin (AST) Pickering emulsion gels stabilized by xanthan gum/lysozyme nanoparticles (XG/Ly NPs) and konjac glucomannan (KGM) were studied from rheological tests and textural analysis. The Pickering emulsion gel demonstrated the highest water holding capacity (WHC) at concentration of 2 % XG/Ly NPs, 60 % oil phase fraction, and 0.5 % KGM concentration. The presence of KGM was observed to enhance the plasticity of Pickering emulsion gels, as evidenced by the dense gel network structure formed on the surface of the droplets. Furthermore, the utilization of Pickering emulsion gels containing AST has demonstrated enhanced photostability and a protective effect on AST, as evidenced by antioxidant experiments. Moreover, the incorporation of KGM in Pickering emulsion gels has been found to reduce the release of free fatty acids (FFA) and the bioaccessibility of AST, as indicated in vitro digestion results. Overall, these findings indicate the potential of KGM-based Pickering emulsion gels as effective vehicles for the delivery of hydrophobic bioactive compounds within the food industry.

Konjac glucomannan promoted fabrication of diacylglycerol oil-based oleogels through emulsion-templated approach: Comparison with triacylglycerol oleogels

Konjac glucomannan (KGM) combined with hydroxypropyl methyl cellulose was used to fabricate diacylglycerol oleogels (DGOs) through the emulsion-templated method, and compared with triacylglycerol oleogels (TGOs). The appearance and microstructure results showed that stable emulsions and oleogels could be formed in the presence of 0.2–0.6 wt% KGM. Higher KGM concentrations resulted in a stronger gel structure in oleogels, whose thixotropic recovery percentages were 50.45–75.20 %. From LF-NMR determination, the higher concentration of KGM presented earlier transverse relaxation (T2) time, and the T2 parameters of DGOs were higher than that of TGOs. Texture and oil loss analysis indicated that the mechanical strength and oil holding ability of DGOs were slightly lower than those of TGOs. This study demonstrated the advantages of biopolymers as thickening agents for obtaining stable emulsion and oleogels. The specific characteristics of DGOs distinguished from TGOs should be attributed to their different properties (unsaturation, viscosity, polarity, etc.) between the liquid oils.

Stability and Rheological Behavior of Mayonnaise-like Emulsion Co-Emulsified by Konjac Glucomannan and Whey Protein.

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.

Effects of konjac glucomannan on physicochemical and rheological properties of whole egg liquid and in vitro fermentation of egg curd

The mixture of proteins, polysaccharides, and other nutrients not only safeguards the nutritional value of the food but also demonstrates superior performance compared to these nutrients when used individually. This study aimed to investigate the effects of konjac glucomannan (KGM) on the properties of whole egg liquid (WEL) and the in vitro fermentation of egg curd (made by the mixture of WEL/KGM). The results revealed that the foaming ability (FA) of the mixture decreased, while the foam stability (FS), emulsifying activity (EA), and emulsion stability (ES) of the mixture increased with increasing concentrations of KGM. The concentration of KGM had a significant effect on the sol-gel transition temperature of WEL. Compared to the fermentation broth of E group (without KGM), KGM decreased the pH from 6.65 to 6.16, free ammonia content from 87.53 μg/g to 72.21 μg/g, and sulfide concentration from 580 μg/L to 470 μg/L in the WEL/KGM mixture (EK group). Moreover, KGM slowed down the gas production of intestinal protein fermentation within 10 h, without affecting the final total gas yield. These findings suggest that adding KGM can be an effective strategy to modify the properties of WEL and improve the intestinal fermentation performance of protein-rich foods.

Characteristics of dried noodle analogue made from sorghum flour and rice flour added with konjac glucomannan

The high popularity of wheat-based food such as noodles in Indonesia has caused a large increase in wheat imports. Sorghum and rice are two local ingredients found in Indonesia; however, sorghum is not largely used as the main grain source, especially in noodle making. This research aimed to determine the effect of the ratio between sorghum flour and rice flour, and konjac glucomannan concentration on noodle analogue characteristics. Konjac glucomannan was added at different concentrations (3%, 4%, 5%) to different ratios of sorghum-rice flours (50:50, 25:75, 0:100). Results showed that the best formulation was a noodle analogue made with a 25:75 sorghum-rice flour ratio and 4% konjac glucomannan. The best-formulated noodle analogue had a higher moisture content (13.35±0.38%), higher fat, and higher carbohydrate (71.93±0.11%), but lower protein and ash content than the commercial wheat-based noodle. It also had a lower starch (60.43%) and dietary fibre content (10.34%), higher cooking loss (9.44±0.60%), and lower water absorption (176.45±4.86%) compared to commercial wheat-based noodle. In terms of textural and mechanical properties, the best-formulated noodle analogue had lower hardness, higher adhesiveness, lower springiness, lower cohesiveness, lower tensile strength, and lower elongation. However, the multiple comparison test showed that panellists perceived the best-formulated noodle analogue to be comparable to commercial wheat-based noodle, in terms of aroma, chewiness, hardness, and adhesiveness.

Heat stability promoted Pickering emulsions stabilized by glidian/sodium caseinate nanoparticles and konjac glucomannan

Pickering emulsions have attracted much attention in the food industry due to their green and non-polluting properties. Effect of konjac glucomannan (KGM) on the heat stability of Pickering emulsions were analyzed by optical microscopy, confocal laser scanning microscope (CLSM), volume mean diameter (d4,3), creaming index (CI) and rheological tests. The results showed that the emulsions without KGM were unstable and delaminated after heat treatment. The d4,3 value of the Pickering emulsion prepared without KGM and 40% oil phase fraction (v/v) was 11.33 ± 0.86 μm at room temperature, while it increased to 35.97 ± 2.00 μm after heat treatment at 100 °C. The Pickering emulsions with KGM concentration of 0.6% and camellia oil content of 60% exhibited desirable particle size and viscoelasticity even after treatment at 100 °C. Therefore, it can be inferred from the results that the increase of KGM concentration and camellia oil content can improve the thermal stability of Pickering emulsion. This study broadens the idea of the processing treatment of Pickering emulsions in food applications and provides a feasible method and theoretical basis for their application in food, pharmaceutical and cosmetic fields.