Addition Of Konjac Glucomannan Research Articles

Nanocellulose aerogels from banana pseudo-stem as a wound dressing

Wound dressings with natural antimicrobial, moisturizing and swelling properties have received increasing attention. However, many natural materials used as wound dressings require chemical cross-linking agents or acidic and alkaline environments and have problems such as poor stability and uneven distribution. In this study, banana nanocellulose (BCNF) with a diameter of less than 70 nm was extracted from banana pseudo-stem through benzyl alcohol extraction, sodium chlorite bleaching, potassium hydroxide alkaline treating, and ultrasonic crushing treatment. There was an addition of konjac glucomannan (KGM) to 0.8 wt% nanocellulose suspension and freeze-drying to form composite aerogel (BCNK) by freeze-drying. Different ratios of BCNF and KGM were used to regulate the performance of aerogels such as swelling, water retention, water vapor transmission rate, and mechanical property. It was evident that the aerogel with an 8/2 mass ratio of BCNF to KGM (BCNK2) exhibited better performance, with a 2981% swelling rate, 97.71% porosity, and 810 g·m−2·d−1 water vapor transmission rate, and also showed the applicable mechanical properties. According to the results of antibacterial and biocompatibility, the composite aerogel had commendable inhibitory effects on E. coli and S. aureus. The hemolysis rate of BCNK2 was 3.38% and the cell survival rate was over 90%, which proved that BCNK2 had good hemolysis and no cytotoxicity. Therefore, the nanocellulose composite aerogel prepared from banana pseudo-stem has the potential to be applied to wound dressings.

Fabrication of biodegradable blend plastic from konjac glucomannan/zein/ PVA and understanding its multi-scale structure and physicochemical properties

Exploration and synthesis of degradable plastics can alleviate and avoid environmental pollution induced by petroleum-based plastics. In this study, a konjac glucomannan (KGM)/zein/PVA ternary blend plastic was successfully prepared by casting. The results showed that, despite the presence of particle aggregation from incompatible components in blend plastic, the addition of KGM and zein improved its compatibility which is consistent with the formation of continuous dark regions and the reduction of roughness average (Ra) results in the AFM characterization. Also, XRD and FT-IR results indicated that the addition of KGM and zein disrupted the molecular and crystalline structure of PVA, induced stretching vibration of alcohol and hydroxyl groups, and crystallinity reduction. In addition, KGM deacetylation (d-KGM) reduced the intramolecular hydroxyl groups, reduced the water absorption and water vapor transmission rate of the blend plastics, and increased the crystallization temperature (Tc) and melting temperature (Tm). Furthermore, the blended plastics exhibited the best tensile strength (TS), elongation at break (E), and elastic modulus (EM) when the proportion of KGM to zein was 9:1. Notably, the blended plastic with KGM and zein added displayed more pores and cracks after soil burial, implying that the lack of degradability of pure PVA plastic was improved.

Pasting and rheological properties of water caltrop starch as affected by the addition of konjac glucomannan, guar gum and xanthan gum

Water caltrop starch (WCS) isolated from the dehydrated water caltrop (DWCS) showed higher content of protein and ash as compared to starch isolated from fresh water caltrop (FWCS), leading to slightly lower starch purity. However, the pasting profiles of DWCS and FWCS are similar under a constant solid content of 4% (w/w). WCS/gum mixed systems contain 0.3%–0.9% gum generally showed higher pasting temperature, peak viscosity, and final viscosity than the starch alone system. The increase in peak and final viscosity during rapid-viscosity analysis was most pronounced for WCS/gum mixed systems with konjac glucomannan (KG), followed by guar gum (GG) and xanthan gum (XG). All WCS/gum mixed systems showed shear thinning and thixotropic characteristics. The extent of pseudoplasticity and shear stability, as evidenced by the smaller flow behavior index (n) and area of the hysteresis loop, was most pronounced for WCS/gum mixed system with XG, followed by mixed systems with GG and KG. Dynamic viscoelastic analysis revealed that the addition of gum increased both the storage and loss moduli of WCS, and lowered the frequency dependence of the loss factor significantly. However, the loss factor of WCS/gum mixed systems was generally higher than that of the starch alone system, implying the addition of gums modified the rheological characteristic of WCS to more viscous dominant behavior.

Mimic Pork Rinds from Plant-Based Gel: The Influence of Sweet Potato Starch and Konjac Glucomannan.

This study investigated the effect of sweet potato starch (SPS) and konjac glucomannan (KGM) on the textural, color, sensory, rheological properties, and microstructures of plant-based pork rinds. Plant-based gels were prepared using mixtures of soy protein isolate (SPI), soy oil, and NaHCO3 supplemented with different SPS and KGM concentrations. The texture profile analysis (TPA) results indicated that the hardness, cohesiveness, and chewiness of the samples improved significantly after appropriate SPS and KGM addition. The results obtained via a colorimeter showed no significant differences were found in lightness (L*) between the samples and natural pork rinds after adjusting the SPS and KGM concentrations. Furthermore, the rheological results showed that adding SPS and KGM increased both the storage modulus (G’) and loss modulus (G’’), indicating a firmer gel structure. The images obtained via scanning electron microscopy (SEM) showed that the SPS and KGM contributed to the formation of a more compact gel structure. A mathematical model allowed for a more objective sensory evaluation, with the 40% SPS samples and the 0.4% KGM samples being considered the most similar to natural pork rinds, which provided a comparable texture, appearance, and mouthfeel. This study proposed a possible schematic model for the gelling mechanism of plant-based pork rinds: the three-dimensional network structures of the samples may result from the interaction between SPS, SPI, and soybean oil, while the addition of KGM and NaHCO3 enabled a more stable gel structure.

The slow release behavior of soy protein isolate/κ-carrageenan composite hydrogel: Effect of konjac glucomannan

Composite hydrogels are known for their potential applications in drug delivery fields. Pure κ-carrageenan (KC) hydrogels have a drug burst release behavior, which greatly limit their applications. In this study, konjac glucomannan (KGM) was used to further improve the properties of soy protein isolate (SPI)/KC composite hydrogels. The results showed that the viscoelasticity of the composite hydrogels increased at KC/KGM ratio 9:1 due to the increase of hydrogen bond interaction. Excessive addition of KGM in composite hydrogels led to the increase in frequency dependence and gel network cavity as well as the decrease in gel cohesiveness. In vitro study on glucose release behavior of composite hydrogels showed that the glucose slow release behavior was enhanced by a small amount of KGM incorporation and had highly positive correlation with the gel viscoelasticity. These results suggested that KGM had the potential to enhance the properties and drug release characteristics of composite hydrogels.

Effects of dietary fibre and soybean oil on the digestion of extruded and roller‐dried maize starch

SummaryThe effects of soybean dietary fibre (SDF), microcrystalline cellulose (MCC), konjac glucomannan (KGM), soluble soybean polysaccharide (SSPS) and soybean oil (SO) on in vitro digestion of extruded maize starch (EMS) and roller‐dried maize starch (RDMS) samples were investigated. Adding MCC, particularly in high doses, induced slow digestion in EMS and RDMS samples, but not after adding SDF. KGM and SSPS addition reduced starch hydrolysis of RDMS but did not have a significant effect on EMS, whereas SO addition reduced starch hydrolysis of EMS but had no effect on RDMS. Principal component analysis demonstrated that the addition of MCC, SO, KGM (0.51%), and SSPS (0.51%) to EMS and KGM (0.51%) to RDMS were the best choices to slow the hydrolysis of starch, compared with that of other additives. These findings provide useful information on the selection of exogenous additives in the development of low glycaemic index products for maize starch.

Nutritional compositions, physicochemical properties, and sensory attributes of green banana flour-based snack bar incorporated with konjac glucomannan

The objective of this study was to determine the nutritional composition, physicochemical properties, and sensory acceptability of snack bars prepared by using green banana flour (20% based on the total weight of rolled oats) and konjac glucomannan (KGM). Various levels of KGM (0.5%, 1.0%, 1.5%, and 2.0%) were incorporated to the snack bar sample formulation to prepare samples of SBKGM0.5, SBKGM1.0, SBKGM1.5, and SBKGM2.0, respectively. Results showed that the incorporation of KGM at increasing levels for snack bar production had significantly (p<0.05) increased the moisture, ash, crude fibre, total carbohydrate, and mineral contents but decreased the crude protein and crude fat contents, as well as calorie values. As for textural properties, the hardness value was significantly increased (p<0.05) with an increased level of added KGM. For overall acceptability by panellists, the addition of KGM up to a maximum of 1.5% to the formulation of green banana-flour based snack bar was recorded as the most suitable for snack bar preparation. These findings could be a useful platform in developing a green banana flour-based snack bar with property improvement, especially in the nutrition and physical aspects.

Effects of konjac glucomannan on pasting, rheological, and structural properties of low-amylose rice starch

Abstract Blend of starch and polysaccharide is a secure and feasible modifying method for starch. Effects of konjac glucomannan (KGM) on pasting, retrogradation, rheological and structural properties of low-amylose rice starch were evaluated. KGM addition reduced the pasting temperature, breakdown and setback values, but raised the peak viscosity. When KGM concentration increased, the storage and loss moduli showed an upward trend. Fourier transform infrared spectroscopy (FTIR) showed redshifts at 3450 and 1640 cm−1 and suggested the formation of intermolecular hydrogen bond between KGM and starch molecules. X-ray diffraction (XRD) indicated that KGM decreased the relative crystallinity from 11.88 to 3.10%. Scanning electron microscopy (SEM) of KGM induced samples showed looser network structures, and confocal laser scanning microscopy (CLSM) detected less cloud-like blurry pastes surrounding around the starch ghosts. KGM addition suppressed the starch retrogradation. These results could be used to broaden the application of KGM in the food industry.

Addition of κ-carrageenan increases the strength and chewiness of gelatin-based composite gel

Although gelatin-based composite gels have been widely used in the food and pharmaceutical industries, further research is needed to improve gel strength. This work reported the microstructure and gel properties of gelatin-based composite gels containing different contents of κ-carrageenan (CGN) or konjac glucomannan (KGM). The rheological and textural results revealed that the gelling temperature, melting temperature, strength (from 1.68 to 4.13 times), toughness, and chewiness of the composite gel were positively correlated with the addition of CGN. The microscopy and infrared spectroscopy showed that gelatin and CGN molecules could be clustered in helices by electrostatic interactions and hydrogen bonding to form excellent gel networks with outstanding gelation properties. However, gelatin and KGM could either be compatible with or separated from each other. At a low KGM content, the gelatin-based composite gel was porous and had a dense gel structure. When the KGM content was 0.3%, the composite gel showed greater ordering degree. Thus, the addition of the proper amount of CGN to gelatin led to composite gels with better strength, toughness, and chewiness, whereas the addition of KGM generated gels being easy to chew and swallow.

Effect of ultrasound assisted konjac glucomannan treatment on properties of chicken plasma protein gelation

The effect of ultrasound assisted konjac glucomannan treatment on the properties of chicken plasma protein gelation was investigated in this study. There were four gelation groups as follows: untreated plasma protein gelation (Control), gelation added konjac glucomannan (KGG), gelation by ultrasound treatment alone (UG) and gelation added konjac glucomannan combined with ultrasound treatment (KGUG). The data showed that the gelation strength and water-holding capacity of the treated groups were significantly increased compared with those of Control. The strongest bonding water was present in KGUG, followed by KGG and UG in low-field nuclear magnetic resonance. The storage energy (G′) and loss energy modulus (G″) of KGUG showed the largest rheological properties, and the G′ value was higher than that of G″. Furthermore, the elastic and gelatinous properties of UG, KGG and KGUG played a dominant role in viscoelasticity. After konjac glucomannan addition, the particle size of KGG increased significantly. Compared with that of the Control and KGG, the average particle size of UG and KGUG decreased significantly after ultrasound treatment. The hydrophobicity and disulfide bonds mainly affected the formation of heat-induced gelation in these four groups. Furthermore, KGUG with the highest hydrophobicity and disulfide bonds revealed the best stability. Therefore, the gelation of chicken plasma protein by ultrasound assisted konjac glucomannan treatment had excellent gelling properties.

Influence of konjac glucomannan on thermal and microscopic properties of frozen wheat gluten, glutenin and gliadin

The effects of different konjac glucomannan (KGM) concentrations (0.5%, 1.5%, 2.5%, 3.5%, 4.5%, w/w) on the thermal and microscopic properties of the frozen wheat gluten, glutenin and gliadin were investigated in this study. KGM exerted a positive effect on the denaturation temperature and denaturation enthalpy of frozen gluten and gliadin, while KGM decreased those of frozen glutenin. Such effects induced by KGM were resulted from the interaction between KGM and frozen wheat gluten, glutenin and gliadin. The underlying mechanism was discussed from the perspective of protein structure. Specifically, the addition of KGM increased the α-helix structure of frozen gluten and gliadin, while decreased the α-helix of frozen glutenin. Furthermore, β-turn of frozen gluten and gliadin presented a decreasing trend with increasing amount of KGM. Scanning electron microscopy confirmed that there was stronger interaction between wheat protein and KGM. These results provide fundamental knowledge for better application of KGM in frozen protein-based foods.

Effects of two contrasting dietary polysaccharides and tannic acid on the digestive and physicochemical properties of wheat starch.

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.

Effects of konjac glucomannan on the long-term retrogradation and shelf life of boiled wheat noodles.

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. 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 < 0.05) decreased with the increase of KGM addition, suggesting the hinderance of starch retrogradation behavior by KGM. The shelf life of BWNs was predicted by accelerated storage test combined with the Arrhenius equation. The present data displayed that the predicted shelf life of vacuum-packed and sterilized BWNs with 10g kg-1 KGM at 25 °C was 733 days, 2.4-fold that of the control group. BWNs with KGM addition could inhibit starch retrogradation and improve the storage stability, consequently promoting noodle quality. © 2021 Society of Chemical Industry.

Konjac Glucomannan Attenuated Triglyceride Metabolism during Rice Gruel Tolerance Test.

In a recent study, we showed that konjac glucomannan (KGM) inhibits rice gruel-induced postprandial increases in plasma glucose and insulin levels. To extend this research, we investigated the effects of KGM addition to rice gruel on pre- and postprandial concentrations of circulating lipoprotein lipase (LPL), glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1), hepatic triglyceride lipase (HTGL), free fatty acids (FFA), and triglycerides (TG). A total of 13 Japanese men, without diabetes, dyslipidemia, or gastrointestinal diseases, interchangeably ingested rice gruel containing no KGM (0%G), rice gruel supplemented with 0.4% KGM (0.4%G), and rice gruel supplemented with 0.8% KGM (0.8%G), every Sunday for 3 weeks. Blood samples were obtained at baseline and at 30, 60, and 120 min after ingestion to measure the abovementioned lipid parameters. Lipid parameters showed small, but significant, changes. Significant reductions were found in circulating FFA levels among all participants. Circulating TG levels significantly declined at 30 min and then remained nearly constant in the 0.8%G group but exhibited no significant difference in the 0%G and 0.4%G groups. Although circulating levels of LPL and GPIHBP1 significantly decreased in the 0%G and 0.4%G groups, they increased at 120 min in the 0.8%G group. Participants in the 0%G and 0.4%G groups showed significant decreases in circulating HTGL levels, which was not observed in the 0.8%G group. Our results demonstrate the novel pleiotropic effects of KGM. Supplementation of rice gruel with KGM powder led to TG reduction accompanied by LPL and GPIHBP1 elevation and HTGL stabilization, thereby attenuating TG metabolism.

The Influence of Konjac Glucomannan on the Physicochemical and Rheological Properties and Microstructure of Canna Starch.

The addition of hydrocolloid is an effective method to improve the properties of native starch. However, few studies have investigated the effects of konjac glucomannan (KGM) on canna starch (CS). In this study, the effects of various KGM concentration on the pasting, rheological, textural, and morphological properties of CS were investigated. The addition of KGM significantly increased CS’s pasting viscosities. Incorporation of KGM in CS at a relatively high level (1.2% w/w) exerted a significant influence on the pasting properties of CS. The consistency coefficient of CS was notably increased by KGM (from 43.6 to 143.3 Pa·sn) and positively correlated positive with KGM concentration. KGM concentration at a relatively high level (1.2% w/w) increased the elasticities and cohesiveness of CS by 53.3% and 88.0%, respectively, in texture profile analysis. The polarized optical microscope images indicated that KGM played an important part in protecting the crystalline structure of CS during heating. A denser porous microstructure with a filamentous network was observed in gelatinized KGM/CS mixtures as compared with the CS control. This research advances the knowledge of interactions between KGM and CS and opens possibilities to improve rheological properties of CS and to develop its new functionalities with KGM addition.

Rheological and microstructural characterization of wheat dough formulated with konjac glucomannan.

This work aimed to investigate the effects of different levels of konjac glucomannan (KGM) on the thermomechanical and pasting properties, water distribution, gelatinization, texture, and microstructural characteristics of wheat flour and dough. The thermomechanical properties assessed with a Mixolab showed that KGM could increase the water absorption and degree of softening and decrease the stability time of wheat dough. In addition, wheat flour starch with KGM underwent significant (P < 0.05) gelatinization changes according to the rapid viscosity analyzer and differential scanning calorimetry results. These results demonstrated that KGM enhanced the thermal stability and anti-aging capacity of wheat flour. All doughs with KGM exhibited viscoelastic behavior but lower hardness and gumminess. Low-field nuclear magnetic resonance showed that water, with a tight binding force, migrated to the weaker binding forces in the dough. A noticeable disruption of the gluten network was observed at the highest level of KGM. However, an intermediate level of KGM addition (10 or 15 g kg-1 flour) still rendered dough with satisfactory properties. A certain amount of KGM could enhance the thermal stability and anti-aging ability of wheat flour, improve the viscoelastic behavior, and decrease the hardness and gumminess of dough. In general, the mixing of flour and dough with KGM addition of 10 or 15 g kg-1 flour was of good quality. © 2021 Society of Chemical Industry.

Shear-induced synergistic effects of konjac glucomannan and waxy potato starch on viscosity and gel strength

Waxy potato starch (WPS) forms a highly viscous and elastic gel under a long-term low shear at a low temperature (24 h, 20 s−1, and 5 °C), and the gel elasticity and storage modulus (G′) increase with the addition of konjac glucomannan (KGM). In this study, a relatively short-term (10 h) of low shear (20 s−1) was applied to the WPS dispersion with the addition of three different KGMs. With a constant low shear, viscosities of KGM/WPS dispersions initially decreased (0–4 h) followed by an increase (4–10 h) back to the level of the initial viscosity. Shear-induced WPS gel formation was accelerated by addition of KGM. The G′ of KGM/WPS gel increased 25 times after shearing for 10 h and was 5 times higher than shear-induced WPS gel, which was caused by the formation of intermolecular double helices of WPS (melting ΔH ≈ 5 J/g; ΔG'(25-95°C)≈ 1100 Pa). Strong shear-induced synergistic effects with KGM and WPS were observed in the viscosity and G′, which was independent of the viscosity and elasticity of KGM dispersion.

Impact of heating and drying temperatures on the properties of konjac glucomannan/curdlan blend films

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.

Influence of pre-acidification, and addition of KGM and whey protein-based fat replacers CH-4560, and YO-8075 on texture characteristics and pizza bake properties of low-fat Mozzarella cheese

The purpose of this study was to investigate the effect of konjac glucomannan (KGM) and microparticulated whey protein-based fat replacers (WPFR) on low-fat Mozzarella cheese. The textural properties, meltability, color, microstructure and pizza bake performance of 0, 7, 14, 21, 28-day-old low-fat cheeses using KGM (LFKGM) or whey protein (LFFR1 and LFFR2) were studied, and fat-reduced cheeses (LFC; milk containing 1.40 g fat/100 g milk) and full-fat cheeses (FFC; milk containing 2.24 g fat/100 g milk) were manufactured as control. The color of Mozzarella cheeses was closely linked to their composition and storage time, especially moisture and fat content and the lightness values of FFC, LFC, LFKGM, LFFR1 and LFFR2 were 90.28, 84.91, 88.48, 91.77 and 91.57, respectively. Textural properties, meltability and baking performance of Mozzarella cheeses generally improved with the supplement of KGM or WPFR and with age. The addition of whey protein or KGM showed much denser microstructure and reduced pockets of serum channels distributed in the protein network throughout refrigerated storage. Positive changes of low-fat Mozzarella cheeses as affected by KGM or whey protein were observed in our study, suggesting WPFR could improve the functionality of cheeses and could be used to reduce fat in dairy products.

Formation of high amylose corn starch/konjac glucomannan composite film with improved mechanical and barrier properties

Recently, starch-based packaging materials have become one of research hot points. In the present study, glycerol-plasticized composite films based on high amylose corn starch (HCS) and konjac glucomannan (KGM) were developed. The influence of KGM on the film-forming properties of HCS and the physicochemical properties of the resulting films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric (TG) analysis and water vapor permeability (WVP). The crystallinity and the proportion of short-range order structure of the films increased first and then declined with the addition of KGM. The micromorphology of the films exhibited the more even texture after KGM was incorporated in. The tensile strength, elongation at break and water resistance of HCS film were also improved significantly. The synergistic effect between HCS and KGM improved the film-forming ability of HCS. The optimal addition amount of KGM was 0.3 %.