Addition Of Konjac Glucomannan Research Articles

Effect of konjac glucomannan on gut microbiota from hyperuricemia subjects in vitro: fermentation characteristics and inhibitory xanthine oxidase activity

BackgroundThe disorder of uric acid metabolism is closely associated with gut microbiota and short-chain fatty acids (SCFAs) dysregulation, but the biological mechanism is unclear, limiting the development of uric acid-lowering active polysaccharides. Konjac glucomannan (KGM) could attenuate metabolic disturbance of uric acid and modulate the gut microbiota. However, the relationship between uric acid metabolism and gut microbiota is still unknown.MethodsIn this study, The fecal samples were provided by healthy volunteers and hyperuricemia (HUA) patients. Fecal samples from healthy volunteers was regarded as the NOR group. Similarly, 10% HUA fecal suspension was named as the HUA group. Then, fecal supernatant was inoculated into a growth basal medium containing glucose or KGM, and healthy fecal samples were designated as the NOR-GLU and NOR-KGM groups, while HUA fecal samples were designated as the HUA-GLU and HUA-KGM groups. All samples were cultured in an anaerobic bag system. After fermentation for 24 h, the samples were collected for further analysis of composition of intestinal microbiota, SCFAs concentration and XOD enzyme activity.ResultsThe results showed that KGM could be utilized and degraded by the gut microbiota from HUA subjects, and it could modulate the composition and structure of their HUA gut microbiota to more closely resemble that of a healthy group. In addition, KGM showed a superior modulated effect on HUA gut microbiota by increasing Megasphaera, Faecalibacterium, Lachnoclostridium, Lachnospiraceae, Anaerostipes, and Ruminococcus levels and decreasing Butyricicoccus, Eisenbergiella, and Enterococcus levels. Furthermore, the fermentation solution of KGM showed an inhibitory effect on xanthine oxidase (XOD) enzyme activity, which might be due to metabolites such as SCFAs.ConclusionIn conclusion, the effect of KGM on hyperuricemia subjects was investigated based on the gut microbiota in vitro. In the present study. It was found that KGM could be metabolized into SCFAs by HUA gut microbiota. Furthermore, KGM could modulate the structure of HUA gut microbiota. At the genus level, KGM could decrease the relative abundances of Butyricicoccus, Eisenbergiella, and Enterococcus, while Lachnoclostridium and Lachnospiraceae in HUA gut microbiota were significantly increased by the addition of KGM. The metabolites of gut microbiota, such as SCFAs, might be responsible for the inhibition of XOD activity. Thus, KGM exhibited a superior probiotic function on the HUA gut microbiota, which is expected as a promising candidate for remodeling the HUA gut microbiota.

Highly ordered aggregation of soy protein isolate particles for enhanced gel-related properties through konjac glucomannan addition

This study assessed the effect of konjac glucomannan (KGM) on the aggregation of soy protein isolate (SPI) and its gel-related structure and properties. Raman results showed that KGM promoted the rearrangement of SPI to form more β-sheets, contributing to the formation of an ordered structure. Atomic force microscopy, confocal laser scanning microscopy, and small-angle X-ray scattering results indicated that KGM reduced the size of SPI particles, narrowed their size distribution, and loosened the large aggregates formed by the stacking of SPI particles, improving the uniformity of gel system. As the hydrogen bonding between the KGM and SPI molecules enhanced, a well-developed network structure was obtained, further reducing the immobilized water's content (T22) and increasing the water-holding capacity (WHC) of SPI gel. Furthermore, this gel structure showed improved gel hardness and resistance to both small and large deformations. These findings facilitate the design and production of SPI-based gels with desired performance.

Fibrin-konjac glucomannan-black phosphorus hydrogel scaffolds loaded with nasal ectodermal mesenchymal stem cells accelerated alveolar bone regeneration

BackgroundEffective treatments for the alveolar bone defect remain a major concern in dental therapy. The objectives of this study were to develop a fibrin and konjac glucomannan (KGM) composite hydrogel as scaffolds for the osteogenesis of nasal mucosa-derived ectodermal mesenchymal stem cells (EMSCs) for the regeneration of alveolar bone defect, and to investigate the osteogenesis-accelerating effects of black phosphorus nanoparticles (BPNs) embedded in the hydrogels.MethodsPrimary EMSCs were isolated from rat nasal mucosa and used for the alveolar bone recovery. Fibrin and KGM were prepared in different ratios for osteomimetic hydrogel scaffolds, and the optimal ratio was determined by mechanical properties and biocompatibility analysis. Then, the optimal hydrogels were integrated with BPNs to obtain BPNs/fibrin-KGM hydrogels, and the effects on osteogenic EMSCs in vitro were evaluated. To explore the osteogenesis-enhancing effects of hydrogels in vivo, the BPNs/fibrin-KGM scaffolds combined with EMSCs were implanted to a rat model of alveolar bone defect. Micro-computed tomography (CT), histological examination, real-time quantitative polymerase chain reaction (RT-qPCR) and western blot were conducted to evaluate the bone morphology and expression of osteogenesis-related genes of the bone regeneration.ResultsThe addition of KGM improved the mechanical properties and biodegradation characteristics of the fibrin hydrogels. In vitro, the BPNs-containing compound hydrogel was proved to be biocompatible and capable of enhancing the osteogenesis of EMSCs by upregulating the mineralization and the activity of alkaline phosphatase. In vivo, the micro-CT analysis and histological evaluation demonstrated that rats implanted EMSCs-BPNs/fibrin-KGM hydrogels exhibited the best bone reconstruction. And compared to the model group, the expression of osteogenesis genes including osteopontin (Opn, p < 0.0001), osteocalcin (Ocn, p < 0.0001), type collagen (Col , p < 0.0001), bone morphogenetic protein-2 (Bmp2, p < 0.0001), Smad1 (p = 0.0006), and runt-related transcription factor 2 (Runx2, p < 0.0001) were all significantly upregulated.ConclusionsEMSCs/BPNs-containing fibrin-KGM hydrogels accelerated the recovery of the alveolar bone defect in rats by effectively up-regulating the expression of osteogenesis-related genes, promoting the formation and mineralisation of bone matrix.

Immobilization of Saccharomyces cerevisiae on polyhydroxyalkanoate/konjac glucan nanofiber membranes: Characterization, immobilization efficiency and cellular activity

Yeast immobilization systems can recoup yeast losses in continuous batch fermentation and relieve substrate or product inhibition. We report the use of solution blow spinning process to efficiently prepare polyhydroxyalkanoate (PHB) /konjac glucomannan (KGM) nanofiber membranes as immobilization carriers for Saccharomyces cerevisiae. The prepared PHB/KGM nanofiber membranes had fiber diameters similar to the scale of yeast cells. Incorporating KGM significantly enhanced the porosity (from 87.21 % to 91.74 %), crystallinity, and hydrophilicity (reducing water contact angle from 135.8° to 110.1°), while increasing the specific surface area (from 10.24 to 17.79 m2/g) of pure PHB nanofiber membranes. Thermal stability was maintained (degradation temperatures above 250 °C). These changes enhanced the force between the nanofiber membranes and the cells and facilitated their autoimmobilization on the nanofiber membranes. The highest yeast immobilization efficiency of 87.93 % could be achieved at a KGM addition ratio of 400:2. Yeast showed no loss of cellular activity on the immobilized carriers of natural materials and maintained or even improved fermentation kinetics during at least three consecutive alcoholic fermentations These findings indicate that PHB/KGM nanofiber membranes can serve as effective carriers for yeast immobilization, promoting the sustainable production of fermented foods.

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.

Composite hydrogels fabricated from konjac glucomannan and gellan gum: Rheological characterization and their potential application in sustainable agriculture

In this study, konjac glucomannan (KG) was incorporated in high acyl gellan (HAG) and low acyl gellan (LAG) hydrogels in different ratios. The addition of KG increased pseudoplasticity and thermal hysteresis values of the hydrogels. Improvement in elasticity and water holding capacity (WHC) was observed in KG-LAG hydrogels. The highest WHC (98.5 %) was observed for 1K1H (KG:HAG = 1:1) and 3K7L (KG:LAG = 3:7) hydrogels. The crystallinity of the composite hydrogels was lower than hydrogels prepared from individual biopolymers. The hydrogels exhibited a rough surface with minute pores in the cross-section, due to the aggregation of glucomannan on the gellan network in the composite hydrogels. While HAG and 1K1H hydrogels exhibited greater swelling at low pH (3.0), LAG and 3K7L exhibited greater swelling at high pH (11.0). At pH 7.0, the hydrogels exhibited swelling indices >300 %. Incorporation of 1K1H hydrogel at 10 % (w/w) in sandy loamy soil under semi-arid conditions increased the germination of fenugreek microgreens from 60 % to 80 % on the 15th day. Furthermore, the moisture evaporation rate of the soil reduced from 35 % to <15 %, positively impacting the physicochemical properties of the microgreens. The composite hydrogels were successful in achieving a controlled release of phosphate fertilizer.

Impacts of Konjac Glucomannan on the Pasting, Texture, and Rheological Properties of Potato Starch with Different Heat–Moisture Treatments

AbstractFew studies reported the impact of hydrocolloid addition on starches after heat moisture treatment (HMT). In this study, potato starch is modified by HMT under different moisture content (18–35%), and the impact of konjac glucomannan (KGM) addition on the pasting, gel texture, and rheological properties of potato starch after HMT are investigated. The results showed that after HMT, the granule structure of the starch is changed with higher heat stability, shown as higher pasting temperature and trough viscosity. The impact of KGM addition is similar on the potato starch before and after HMT, but the change extent of the latter is larger in most cases, such as decreased pasting temperature and gel hardness, increased peak viscosity, breakdown viscosity, and final viscosity. This indicated that KGM benefited the gelatinization behavior of HMT starch but might not enhance the retrogradation process. The intrinsic high viscosity of KGM in water resulted in a softer starch gel and also contributed to the enhanced shear stress of the mixture paste. Therefore, the impact of KGM on the HMT starch is more significant than the original starch, and this guided the use of HMT starch in the food industry with other hydrocolloid involvement.

Improved qualities of salt-reduced tilapia surimi by adding konjac glucomannan: Insight into the edible traits, gel properties and anti-freezing ability

This study aimed to investigate the potential of different levels (0.05%, 0.1%, 0.15%, 0.2%, and 0.25%, w/w) of konjac glucomannan (KGM) supplement in improving the gel quality and anti-freezing ability of salt-reduced tilapia surimi (1.25% NaCl, w/w). Directly reducing the salt addition level generated adverse effects on the water retention of gel, network structure, and texture compared to those of surimi added with normal salt level (2.5% NaCl). A proper KGM supplement (0.15%, w/w) effectively improved the low-salt surimi gel strength and whiteness, accompanied by less liquid loss. The microstructure results intuitively illustrated that excess addition of KGM was prone to absorbing sufficient water in the composite gel and hinder protein-protein cross-linking, rendering the continuous network looser. In terms of frozen storage, the salt-reduced surimi supplied with KGM shortened the time spent in forming the maximum ice crystals. The mechanical damage induced by ice crystals and the subsequent thawing loss of frozen surimi were thus alleviated. Supplement of KGM added to low-slat frozen surimi could enhance freezing-thawing stability by the modification of ice crystals, limited water migration, and inhibition of network destruction. The TBA and rheology results further indicated that KGM displayed anti-oxidation ability, and enhanced the salt-reduced surimi stability during frozen storage. Hence, an appropriate KGM supplement could be a feasible strategy to minimize the gel deterioration and improve the anti-freezing ability of low-salt surimi gel.

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.

Electrospun Konjac Glucomannan/Polyvinyl Alcohol Long Polymeric Filaments Incorporated with Tea Polyphenols for Food Preservations.

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.

Inclusion of konjac glucomannan in pea protein hydrogels improved the rheological and in vitro release properties of the composite hydrogels

In this study, a composite hydrogel consisting of pea protein and konjac glucomannan (KG) was fabricated using three approaches, namely neutral, salt-set, and alkaline gelation. Hydrogels made from pea protein were brittle and weak. The addition of KG improved the elasticity and water holding capacity of the pea protein hydrogels. Concomitantly, a decrease in syneresis rate and swelling of the composite hydrogels was observed. The alkaline-set hydrogels exhibited the highest resilience to strain. Thixotropicity was found to be less pronounced for salt-set hydrogels. Sulphate had a greater positive effect on the structural recovery and negative effect on hysteresis area than chloride due to the greater salting-out effect of the sulphates. The addition of KG facilitated the formation of an interconnected structure with limited mobility of biopolymer chains. A sharp increase in G' and G" during the temperature ramp indicated the predominance of hydrophobic interactions towards the aggregation of biopolymers. The infrared spectra of the hydrogels revealed a change in secondary structure of proteins on addition of KG. A controlled in vitro release of riboflavin was observed in neutral and salt-set hydrogels. The alkaline-set hydrogels exhibited a prolonged gastric retention time, thereby establishing in vitro antacid activity in the gastric environment.

Effect and characterization of konjac glucomannan on xanthan gum/κ-carrageenan/agar system

A mixed polysaccharide system is an important strategy to improve the performance of a single polysaccharide. Herein, quaternary polysaccharide gels were prepared by konjac glucomannan (KGM), xanthan gum (XG), κ-carrageenan (κ-CA), and agar (AR). The effects of KGM were evaluated by combining water holding capacity (WHC), rheological analysis, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and texture profile analysis (TPA). More KGM gradually increased the springiness of the compounded gels. WHC increased and then decreased with the addition of KGM, performing best at KGM4 (KGM: κ-CA:XG:AR = 2:2:1:2). Rheological analysis showed that the compounded gels exhibited a pseudoplastic characteristic of shear thinning, KGM endowed the gel with a stronger shear thinning behavior and improved the solid-like nature of the gels at high temperatures. The thermal stability of the composite gel was improved by the participation of KGM. FTIR analysis showed that the interactions were mainly related to intermolecular hydrogen bonds and acetyl groups. The microscopic morphology of KGM4 was significantly continuous, smooth, and compact, exhibiting the best practical performance and taking the maximum advantage.

Effects of konjac glucomannan as a freeze-denaturation inhibitor or binder on the physiochemical properties of heat-induced gel of freeze-dried duck blood.

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 2.14kg, which significantly reduced to 0.12-0.87kg 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.

Colorimetric gel labels for the non-destructive freshness monitoring of fresh-cut papaya

Colorimetric gel labels (referred to as AKAX) were fabricated to monitor the freshness of fresh-cut papaya in real time using agarose (AR) and konjac glucomannan (KGM) composite gels containing alizarin (AL) and Substance X (X). The AKAX colorimetric gel label produced an ordered color variation from purple to pink-purple to orange-yellow, following the CO2 concentration in the package, to reflect the fresh-cut fruit freshness. Experimental characterization of the gel label structure revealed that AR, KGM, AL, and X were compatible, while the gel label texture, water-holding capacity, rheology, and thermal stability were improved with the addition of KGM. AKAX colorimetric gel labels maintained excellent color stability and CO2 sensitivity during storage at 4 °C. The fresh-cut papaya approached spoilage as the color varied from purple to pink-purple, and an orange-yellow color indicated that the fresh-cut papaya had spoiled. Therefore, the developed AKAX colorimetric gel labels serve as effective tools for monitoring the spoilage of fresh-cut papaya.

Effect of variation in basic emulsion structure and polysaccharide content on the physicochemical properties and structure of composite-based emulsion gels as cube fat mimetics

This study aimed to reveal the effect of different basic emulsion structures (W/O/W and O/W) and polysaccharide additions on protein-polysaccharide composite-based emulsion gels utilizing soybean protein isolate, palm oil and konjac glucomannan. The results of texture profile, rheological tests, microstructure observations, and oral tribology showed that basic emulsion structures and konjac glucomannan addition had significant effect on the emulsion gels' properties, while the impact of konjac glucomannan addition was stronger. W/O/W double emulsion gels (DEG) exhibited lower oral friction coefficients and obtained higher scores for oiliness and juiciness during the sensory evaluation. However, O/W single emulsion gels (SEG) displayed a firmer texture and higher chewiness, a 29.62% and 49.57% increase compared to the DEG at 7% konjac glucomannan addition on the hardness and chewiness respectively. It has demonstrated the emulsion gels' potential as cube fat mimetics and feasibility of adjusting their properties by changing the basic emulsion structure.

Fabrication of grape seed proanthocyanidin-loaded W/O/W emulsion gels stabilized by polyglycerol polyricinoleate and whey protein isolate with konjac glucomannan: Structure, stability, and in vitro digestion.

In this work, the effects of konjac glucomannan (KGM) concentrations on microstructure, gel properties, stability and digestibility of water-in-oil-in-water emulsion gels stabilized by polyglycerol polyricinoleate and whey protein isolate were investigated. Visual appearance indicated that a non-layered double emulsion gel was formed when KGM increased to 0.75%. Emulsion gels with 1.5% KGM showed the highest encapsulation, freeze-thaw and photochemical stability due to the formation of the smallest droplets, which were supported by microscopic observations. Moreover, the addition of KGM improved water holding capacity, rheological and texture properties of emulsion gels. Particularly, at 1.5% or 1.75% KGM, color and potential of hydrogen showed the most stable level after 14days of storage. During in vitro digestion, KGM delayed the hydrolysis of protein and oil droplets, and then improved the bioavailability of grape seed proanthocyanidin. These results promoted the application of KGM in emulsion gels and the encapsulation of nutraceuticals.

Physiochemical characteristics and sensory properties of plant protein isolates-konjac glucomannan compound gels.

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.

Studies on stabilized mechanism of high internal phase Pickering emulsions from the collaboration of low dose konjac glucomannan and myofibrillar protein

In this study, the effects of different concentrations (0%, 0.25%, 0.5%, 1%, 1.5%, w/v) of konjac glucomannan (KGM) on the structure and interfacial adsorption of myofibrillar protein (MP) and the mechanism of co-emulsification of high internal phase Pickering emulsions (Pickering HIPEs) by KGM and MP were investigated. The results showed that for interfacial MPs, KGM addition promoted MP structure unfolding and improved MP wettability with a three-phase contact angle from 73.69° (control) to 89.41° (0.5% KGM), thereby lowering the energy barriers to MP penetrating and rearranging at the interface. Furthermore, the adsorption kinetics and protein adsorption percentage (AP%) indicated that KGM (≤1%) facilitated the adsorption of MP from the aqueous phase to the oil-water interface. For MP in the aqueous phase, KGM induced a denser MP network structure by promoting “concentrated” MP and connecting MP through hydrogen bonding, which formed a stronger spatial site resistance and hindered oil droplet aggregation. KGM (≤1%, especially 0.5%) resulted in reduced droplet size, relaxation time (T2), lipid oxidation, and improved storage stability and energy storage modulus of Pickering HIPEs. However, the competitive adsorption of KGM (>1%) significantly decreased the interface MP, and the formation of continuous KGM hydrogel formed an unaggregated MP network structure, decreasing the emulsion performance further. Overall, KGM could modulate the physical properties of MP-stabilized Pickering HIPEs by altering the interfacial adsorption and network structure.

Yeast protein-based meat analogues: Konjac glucomannan induces the fibrous structure formation by modifying protein structure

Carbohydrate polymers can induce the fibrous structure formation of meat analogues during high-moisture extrusion (HME). In this study, meat analogues were prepared using HME (60% moisture) from yeast protein (YP) and konjac glucomannan (KGM) blends. The impact of KGM (0, 1, 2, 4%, wet basis) addition on the textural, rheological, thermal, and structural properties of high-moisture meat analogues (HMMA) was investigated. The results indicated that KGM strengthened the hardness and chewiness and adjusted the formation and orientation of fibrous structures in HMMA. When the content of KGM reached 1%, the texture of HMMA was optimal. The rheological and thermal results showed that an appropriate KGM content (<4%) enhanced the structure of HMMA, which is consistent with the textural results. In addition, the structural results (ultraviolet–visible spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy, surface hydrophobicity, disulfide bond content, and X-ray diffraction) demonstrated that KGM increased the protein aggregation, β-sheet structure, S–S bond content, and ordered degree of HMMA, which were closely related to its texture and fibrous structure. The formation mechanism of KGM-induced fibrous structures in HMMA was preliminary clarified by the protein structure results. Moreover, the study suggested that YP in combination with KGM can be used to produce HMMA with a rich fibrous structure.

Structural properties of meat analogue with added konjac gels

This study reports the physicochemical, rheological, and microstructural properties of patty analogue formulated with fermented soybean where addition of konjac glucomannan with different concentrations (0, 2, 4 and 6%w/w) were evaluated. Konjac was incorporated in the formulation to enhance the eating and textural quality of the patty. Addition of konjac did not altered (p > 0.05) the protein concentration and colour (p > 0.05) of cooked patty, however water retention improved (p < 0.05) which contributed to a better moisture binding. The analogue textural profiles and structure were found to be related to their viscoelastic properties and were strongly affected due to the presence of konjac in the formulation. The results showed the patty analogue was firmer (p < 0.05), more cohesive (p < 0.05) with less in stickiness (p < 0.05) when konjac was incorporated, suggesting the molecular interactions had strengthened the patty network structure. Rheological properties of analogue patty with konjac indicated the patty was predominantly elastic (G’>G”) and the molecular association continued progressively during heating/cooling temperature sweep. Microstructure of this analogue indicated the konjac had acted as a bridge of polymer interactions and leading to more connected patty networks. Hence, the addition of konjac in the fermented soybean patty is worth considering.