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Health-promoting effects of konjac glucomannan and its practical applications: A critical review
Abstract
Konjac glucomannan (KGM) is a dietary fiber hydrocolloidal polysaccharide isolated from the tubers of Amorphophallus konjac. Over the last few decades, the purified KGM has been offered as a food additive as well as a dietary supplement in many countries. Also, a diet containing konjac flour or KGM is considered as healthier, and these foods are popular in many Asian and European markets. Further, due to the adhesive property of KGM, it can form a defensive covering on the surface of the intestine. Additionally, KGM can reduce the levels of glucose, cholesterol, triglycerides, and blood pressure and can enable weight loss. Its wide-ranging effects prevent many chronic diseases through the regulation of metabolism. In this review, the recent studies on the health benefits such as anti-diabetic, anti-obesity, laxative, prebiotic, and anti-inflammatory activities of KGM were discussed. Also, this review deals with the applications of KGM and its derivatives in bio-technical, pharmaceutical, tissue engineering, fine chemical fields, etc.
... Konjac glucomannan (KGM) is recognized as a long-chain polysaccharide that contains D-mannose and D-glucose linked by β-1,4 linkages (Yuan, Xu, Cui, & Wang, 2019). KGM is a non-digestible polysaccharide in human gastrointestinal tracts as amylase in human saliva and pancreas cannot break down the β-1,4 linkages within KGM (Devaraj, Reddy, & Xu, 2019). However, KGM could be fermented by intestinal bacteria (Devaraj et al., 2019). ...
... KGM is a non-digestible polysaccharide in human gastrointestinal tracts as amylase in human saliva and pancreas cannot break down the β-1,4 linkages within KGM (Devaraj, Reddy, & Xu, 2019). However, KGM could be fermented by intestinal bacteria (Devaraj et al., 2019). It has been widely applied as a food additive to improve the physicochemical properties of foods and develop healthy food products. ...
... For instance, KGM was utilized in restructured seafood products (Herranz, Tovar, Solo-de-Zaldívar, & Borderias, 2012), fish surimi (Herranz, Tovar, Borderias, & Moreno, 2013), and cheese pie (Marcano, Hernando, & Fiszman, 2015) to promote gel qualities; in processed cheese (da Silva, de Souza Ferreira, Bruschi, Britten, & Matumoto-Pintro, 2016;Dai, Jiang, Shah, & Corke, 2019), meat products (Jimenez-Colmenero, Cofrades, Herrero, Solas, & Ruiz-Capillas, 2013), and mayonnaise (Li, Wang, Jin, Zhou, & Li, 2014), as a fat replacer. The significant contribution of KGM to health includes weight loss, the maintenance of blood glucose and cholesterol level, the enhancement of intestinal motion, and the improvement of immune system function (Devaraj et al., 2019). These health benefits of KGM are intensively associated with its ability to provide a sense of satiety as it can form a highly viscous and gel-like matrix during digestion, which prolongs gastric emptying and reduce subsequent energy intake (Marcano et al., 2015). ...
Konjac glucomannan (KGM) provides a sense of fullness by delaying physiological processes related to food digestion, which helps weight management and cholesterol maintenance. This study assessed the influence of KGM on the digestive performance of a plant-based fishball (PFB) analogue during in vitro digestion via nuclear magnetic resonance (NMR) spectroscopy and rheological measurements. A total of 27 metabolites were identified, such as amino acids, sterols, saccharides, and fatty acids. Moreover, KGM generally decreased the released amino acids, glucose, and fatty acids. It is possible because KGM affected the metabolic pathways of amino acids and carbohydrates, based on Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Furthermore, PFB6.5 (PFB with 6.5% of KGM) digesta exhibited significantly higher yield stress τ0 (28.0 Pa), consistency coefficient K (46.25 Pa·Sⁿ), and viscoelasticity G0* (749 Pa) than PFB3.5 (9.2 Pa, 14.66 Pa·Sⁿ, 188 Pa). Besides, surface morphology indicated that fishball digesta became more porous, dissociative, and fragmented than PFB, revealing KGM reduced the breakdown of proteins. In conclusion, KGM prolonged the digestion and decreased metabolite release of PFB, which may help control appetite and reduce postprandial blood glucose levels.
... Konjac glucomannan (KGM), which is a soluble dietary fiber, is used as a component of supplements for weight loss [4]. KGM is a reserve polysaccharide contained in the konjac tuber, is a polymer compound formed by the binding of glucose and mannose through β-1, 4 glycogen bonds, is an excellent kind of dietary fiber, and has good water retention, gelling, and thickening properties [5]. Studies have reported that it can reduce body weight, prevent and cure hypertension, increase insulin sensitivity, and exert anti-inflammatory, antioxidation, and other effects [6]. ...
... Zhou et al. [26] demonstrated that DHI treatment attenuates atherosclerosis and macrophage lipid accumulation by the activation of PI3K/AKT signaling pathway. When cells are stimulated, PI3K is phosphorylated to produce phosphatidylinositol-3 [3][4][5] -triphosphate (PIP3), which is the second messenger in Akt transport to the plasma membrane [27]. On the cell membrane, PIP3 promotes the phosphorylation of protein kinase B (Akt) to form P-Akt, which causes the proliferation of biological cells. ...
Atherosclerosis (AS) is the main cause of cardiovascular disease and cerebral infarction, which seriously endanger human health. This study aimed to investigate konjac glucomannan (KGM) defends against high-fat diet-induced AS in rabbits by promoting the PI3K/Akt pathway. KGM administration reduced the degree of AS indicated by reducing the plaques and foam cells, the tunica intima thickness, and the tunica intima/tunica media thickness ratio in the aorta, and enlarging the lumen of the aorta. In addition, KGM administration regulated blood lipids, ameliorated inflammation indicated by reducing the levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, CRP, and VCAM-1, and attenuated endothelial injury, simultaneously mitigated oxidative stress indicated by decreasing MPO activity and the concentrations of MDA and increasing the GSH-Px and SOD concentrations. Moreover, KGM promotes the phosphorylation of PI3K and AKT. However, these effects of KGM on rabbits with high-fat diet-induced AS were blocked by LY294002. In conclusion, KGM defends against high-fat diet-induced AS in rabbits by promoting the PI3K/Akt pathway.
... It has up to 170 varieties, mainly distributed in Southeast Asia and Africa. These varieties are perennial plants with an underground stem in the form of a corm and a highly dissected umbrella-shaped leaf blade [22]. Konjac has a history of more than 2000 years and is a very popular food in China and Japan. ...
... Although the mechanism of the hypolipidemic effect has not been fully understood, it is presumed to be achieved by increasing the excretion of sterols or bile acids, and this presumption has been confirmed by experimental studies in animals [53]. Compared with other dietary supplements, KGM lowers the primary endpoint of metabolic control and various indicators of diabetes such as plasma cholesterol, LDL-C, total/HDL-C ratio, and ApoB [22]. KGM supplementation increased the expression of lipid metabolism-related genes (PPARα, CPT1, Hs1) and lipid transport-related genes (FABP1, apoB100, and CD36), and decreased the expression of lipid synthesis-related genes (srebp1, PPARγ, Fas) [54]. ...
There are many factors causing T2DM; thus, it is difficult to prevent and cure it with conventional treatment. In order to realize the continuous intervention of T2DM, the treatment strategy of combining diet therapy and traditional medication came into being. As a natural product with the concept of being healthy, konjac flour and its derivatives are popular with the public. Its main component, Konjac glucomannan (KGM), can not only be applied as a food additive, which greatly improves the taste and flavor of food and extends the shelf life of food but also occupies an important role in T2DM. KGM can extend gastric emptying time, increase satiety, and promote liver glycogen synthesis, and also has the potential to improve intestinal flora and the metabolic system through a variety of molecular pathways in order to positively regulate oxidative stress and immune inflammation, and protect the liver and kidneys. In order to establish the theoretical justification for the adjunctive treatment of T2DM, we have outlined the physicochemical features of KGM in this article, emphasizing the advantages of KGM as a meal for special medical purposes of T2DM.
... The content of KGM in the grown konjac can reach 60% (Gómez et al., 2017). KGM also contains alkaloids, pectin, amino acids and trace elements, including potassium, phosphorus and selenium (Devaraj et al., 2019). KGM is a non-ionic polymer polysaccharide composed of D-glucose and D-mannose through a β-1,4-pyranoside bond in a molar ratio of 1 : 1.6 to 1 : 1.4. ...
... After KGM absorbs water, it can quickly swell in the stomach to form a highly viscous konjac gum solution, which cannot be digested by the stomach in a short time. This feature delays the emptying of the stomach, prolongs the time for food to enter the small intestine from the stomach and forms an immobile water layer on the surface of the intestinal mucosa (Devaraj et al., 2019). This blocks the digestion and absorption of most carbohydrates and monosaccharides and reduces the rate of glucose absorption by the intestines, thereby lowering blood sugar levels. ...
Abstract In today’s society, the incidence of diabetes is getting higher. It can cause a variety of complications and endanger human health. How to safely and effectively reduce blood sugar has become a hotspot of concern. Konjac dietary fibre is one of the most excellent soluble dietary fibres found so far. Its health benefits include weight loss, lowering blood fat and blood sugar, and it has a laxative effect. This article mainly reviews the clinical observations, related mechanisms of action, appropriate dosages and toxic side effects, providing a basis for the clinical application of konjac dietary fibre and proposing a new mechanism for its hypoglycaemic effect. It provides new ideas for the research and development of konjac in the prevention and treatment of diabetes.
... Glucomannan is a high molecular-weight polysaccharide mainly composed of dmannose and d-glucose linked by β-1,4 glycosidic bonds with side chains [109]. Although it can be present in other plants, such as lily and orchid, glucomannan for human consumption is commonly derived from the tuber or root of Amorphophallus konjac or elephant yam [110]. ...
... It is a hygroscopic fiber, however, which puts it in a subcategory of fibers, such as guar gum, which are viscous and able to form a large volume of mucilage after absorbing water in the upper GI tract. The mucilage can then affect satiety as well as nutrient digestion, absorption, and metabolism in the GI tract [109]. ...
Dietary supplements for weight management include myriad ingredients with thermogenic, lipotropic, satiety, and other metabolic effects. Recently, the safety of this product category has been questioned. In this review, we summarize the safety evidence as well as relevant clinical findings on weight management and metabolic effects of six representative dietary supplement ingredients: caffeine, green tea extract (GTE), green coffee bean extract (GCBE), choline, glucomannan, and capsaicinoids and capsinoids. Of these, caffeine, GTE (specifically epigallocatechin gallate [EGCG]), and choline have recommended intake limits, which appear not to be exceeded when used according to manufacturers’ instructions. Serious adverse events from supplements with these ingredients are rare and typically involve unusually high intakes. As with any dietary component, the potential for gastrointestinal intolerance, as well as possible interactions with concomitant medications/supplements exist, and the health status of the consumer should be considered when consuming these components. Most of the ingredients reviewed also improved markers of metabolic health, such as glucose, lipids, and blood pressure, although the data are limited for some. In summary, weight management supplements containing caffeine, GTE, GCBE, choline, glucomannan, and capsaicinoids and capsinoids are generally safe when taken as directed and demonstrate metabolic health benefits for overweight and obese people.
... Konjac tubers contain glucomannan or a source of water-soluble fiber which is quite high, namely 79.91% (Xiao et al., 2022). Glucomannan from konjac is biodegradable, has antioxidant power, low toxicity, is cheap, and is easy to apply (Devaraj et al., 2019;Wang et al., 2022). The function of glucomannan is as an emulsifier or emulsifier which is often applied in the food industry because glucomannan can form a gel that has a fairly high viscosity when it is in a liquid (Suriati et al., 2020a). ...
Siamese orange fruit is very popular today, driven by the increasing public demand or healthy food. Siamese oranges contain bioactive phenolic compounds, carotenoids, vitamins, minerals, and fiber which are good for health. The weakness of Siamese oranges is their quality declines quickly and their short shelf life. Postharvest handling with the application of coatings from natural ingredients to extend the shelf life of orange fruits is currently needed to reduce the use of synthetic materials. Natural ingredients that have the potential to be used as base materials for coatings are konjac tubers because they contain glucomannan polysaccharides and bioactive compounds that can form coatings. The purpose of this study was to determine the effect of nanocoating-konjacon the shelf life of Siamese oranges. The research began with the preparation of the nanocoating-konjac formula as the main ingredient of the nanocoating and the application of the nano coating-konjac on the surface of Siamese oranges. This study used a completely randomized two-factor design, namely nanocoating-konjac application (without coating, coating, and nanocoating) and storage time (0, 5, 10, and 15 days), three replications. Variables observed: Weight loss, number of damaged fruits, color, texture, acidity, total soluble solids, water content, vitamin C, and total plate count. The data obtained was tested for diversity with SPSS, if it shows differences the test is continued with Duncan's Multiple Range Test. The conclusion of this research is the application of nanocoating-konjac, coating-konjac and without coating on Siamese oranges to determine the effect of weight loss, number of damaged fruits, color, texture, acidity, total dissolved solids, water content, vitamin C, and total plate count during storage. This research recommends that the application of nanocoating-konjac as postharvest handling can extend the shelf life of Siamese oranges until the 10th days.
... Wei et al., 2022). One of the suggested mechanisms is the regulation of the nuclear factor kappa B pathway and possible reduction in the population of these inflammatory cells thus preventing oxidative stress and reducing inflammation (Devaraj et al., 2019;Y. Zhao et al., 2020). ...
This study aimed to formulate and evaluate a floating raft system for the co-delivery of etoricoxib (ETO) and famotidine (FAM) using a combination of glucomannan with natural/semi-synthetic polysaccharides. Formulation variables affect gelation lag time (GLT), floating lag time (FLT), and release percentage of drugs after 1–8 h, Stability, and viscosity parameters were evaluated. In vivo X-ray studies, followed by the pharmacokinetic study, were performed on human volunteers. Formulations exhibited pseudoplastic behavior for ease of swallowing. The optimum raft system (ORS) comprised 1% Na alginate, 0.1% Low Methoxyl (LM) pectin, 0.8% Konjac glucomannan (KGL), 1% Precirol, and 1% CaCO3. ORS exhibited rapid GLT and FLT (around 42 and 8 sec respectively) in 0.1 N HCl as well as controlled release of ETO (15% in 1 h and 82% in 8 h) and FAM (29% in 1 h and 85% in 8 h). Formulation stability with the absence of any drug-excipient interactions was observed. The X-ray imaging showed a promising buoyancy ability for approximately 8 h. Compared with marketed products, ORS showed superior relative bioavailability for both drugs. These findings revealed the successful preparation of a promising raft system with improved dual drug delivery.
... KGM molecular chains can intertwine with macromolecular chains through hydrogen bonding and van der Waals forces and form a three-dimensional mesh structure that generates a synergistic effect, especially when combined with carrageenan, xanthan gum or guar gum [32,58]. The stabilizing and thickening abilities of KGM are essential for its wide application with other natural biomacromolecule-based gels in aquatic foods preservation, packaging, drilling, coating, pharmaceuticals and cosmetics [59,60]. ...
Konjac glucomannan (KGM) is a natural polysaccharide extracted from konjac tubers that has a topological structure composed of glucose and mannose. KGM can be used as a gel carrier to load active molecules in food preservation. The three-dimensional gel network structure based on KGM provides good protection for the loaded active molecules and allows for sustained release, thus enhancing the antioxidant and antimicrobial activities of these molecules. KGM loaded with various active molecules has been used in aquatic foods preservation, with great potential for different food preservation applications. This review summarizes recent advances in KGM, including: (i) structural characterization, (ii) the formation mechanism, (iii) preparation methods, (iv) functional properties and (v) the preservation of aquatic food.
... These common foods are quite favored by consumers, especially those with body weight management needs, for these foods are lower in energy density, but higher in satiating capacity. Meanwhile, the anti-obesity activity of KGM has been studied widely, and numerous studies have reported its effect on a food's glycemic index, on reducing cholesterol and body weight loss, and on regulating gut microbiota [8]. ...
Dietary fiber has been widely used in designing foods with a high satiating capacity, as the use of satiety-enhancing food is considered to be a promising strategy for combating obesity and the overweight condition. In the present study, partially degraded konjac glucomannan (DKGM) diets with different water-holding capacities, swelling capacities, and viscosities were used to feed rats to investigate the effects of the fiber’s physical properties in regulating the appetite response of the animals. The results showed that the mass and water content of the gastrointestinal chyme increased as the diet’s physical properties were enhanced by the DKGM, which increased the stomach distention of the rats and promoted satiation. Besides, the hydrated DKGM elevated the chyme’s viscosity, and the retention time of the digesta in the small intestine was prolonged significantly, which resulted in an increased concentration of cholecystokinin-8, glucagon-like peptide 1, and peptide tyrosine-tyrosine in the plasma, thus helping to maintain the satiety of rats. Furthermore, the results of the behavioral satiety sequence and meal pattern analysis showed that DKGM in the diets is more likely to reduce the food intake of rats by enhancing satiety rather than satiation, and will finally inhibit excessive weight gain. In conclusion, the physical properties of dietary fiber are highly related to the appetite response, which is a powerful tool in designing food with a high satiating capacity.
... It has been generally recognized as safe by a consensus of scientific opinions since 1994 [9,10]. KGM has a dual functionality; on the one hand, it is highly beneficial for human health [11]. KGM cannot be hydrolyzed by digestive enzymes in the human upper gastrointestinal tract and, therefore, is considered as a non-calorie indigestible dietary fiber. ...
Effects of two high pressure processing treatments and various levels of konjac glucomannan (KGM) and sodium caseinate (SC) on texture properties, water-holding capacity, and ultra-structure of gels of rabbit myosin protein were investigated. The two high pressure processing treatments were as follows: (1) mean pressure (200 MPa), low temperature (37 °C), and holding for a short time (5 min) followed heating (80 °C for 40 min) (gel LP + H), and (2) high pressure (500 MPa), high temperature (60 °C), and holding for a long time (30 min) (gel HP). Gel LP + H have better gel properties (increased hardness, springiness, gumminess, adhesiveness, cohesiveness, and water binding capacity) than gels HP. Above all, gels myosin + SC:KGM (2:1) have best gel properties. KGM and SC both significantly improved the gel texture properties and water binding capacity.
... Meanwhile, natural polysaccharides extracted from plants and seeds in synergism with alginate have been commonly used to produce edible films . Konjac (Amorphophallus konjac) gum, for instance, is a low-cost hydrocolloid, composed mainly of glucomannan, extracted from konjac tubers (Devaraj et al., 2019). This gum produces viscous and stable gels with film-forming capacities and has been related with food microbial preservation (Hashemi & Jafarpour, 2020Li et al., 2021). ...
... They also increase the viability of macrophages, suggesting that glucomannans have the potential to activate macrophages [39]. Because glucomannans are water-soluble, non-ionic hydrocolloidal dietary fibers, they have health-promoting effects, such as anti-diabetic, anti-obesity, laxative, prebiotic, and anti-inflammatory activities [44]. EPS produced by L. paracasei EPS DA-BACS are suggested to also have prebiotic and anti-inflammatory effects. ...
Exopolysaccharide (EPS)-producing Lacticaseibacillus paracasei EPS DA-BACS was isolated from healthy human feces and its probiotic properties, as well as the structure and prebiotic activity of the EPS from this strain were examined. EPS from L. paracasei EPS DA-BACS had a ropy phenotype, which is known to have potential health benefits and is identified as loosely cell-bounded glucomannan-type EPS with a molecular size of 3.7 × 106 Da. EPS promoted the acid tolerance of L. paracasei EPS DA-BACS and provided cells with tolerance to gastrointestinal stress. The purified EPS showed growth inhibitory activity against Clostridium difficile. L. paracasei EPS DA-BACS cells completely inhibited the growth of Bacillus subtilis, Pseudomonas aeruginosa, and Aspergillus brasiliensis, as well as showed high growth inhibitory activity against Staphylococcus aureus and Escherichia coli. Treatment of lipopolysaccharide-stimulated RAW 264.7 cells with heat-killed L. paracasei EPS DA-BACS cells led to a decrease in the production of nitric oxide, indicating the anti-inflammatory activity of L. paracasei EPS DA-BACS. Purified EPS promoted the growth of Lactobacillus gasseri, Bifidobacterium bifidum, B. animalis, and B. faecale which showed high prebiotic activity. L. paracasei EPS DA-BACS harbors no antibiotic resistance genes or virulence factors. Therefore, L. paracasei EPS DA-BACS exhibits anti-inflammatory and antimicrobial activities with high gut adhesion ability and gastrointestinal tolerance and can be used as a potential probiotic.
... The basic unit of KGM is shown in Figure 1, which contributes to construct the final tertiary structure [17], the first level is a linear one composed of glucose and mannose as repeating units according to a certain molar ratio, the second level is a two-fold helix presented by the extension of KGM main chains, and the third level is the 3D network based on the rotation of the secondary structure. Owing to such unique structure, KGM exhibits physicochemical characteristic summarized as rheology, thickening, gelling, film-forming and water retention property [18][19][20], especially the gelling and film-forming, which make it possible to process KGM into membrane [21,22]. Baking-carbonization is processed at a relatively low-temperature, the natural herbaceous plants experienced this treatment changes into carbon materials, meanwhile, it retains the aroma sources from raw materials, which can be realized a certain aroma enhancement effect [23,24]. ...
To develop one porous additive material that can be assembled on cigarette filter, and achieve both functions of reducing hazard substances like tar and providing special aroma and moisture, this study innovatively selects the raw materials like baking-carbonized functional flavors with special aroma and konjac glucomannan (KGM) with properties of water absorption, gelling and film-forming, following the steps of casting into membrane shape, thermostatic crosslinking for strength enhancement and freeze-drying for pore creating to prepare 5 porous composite membranes based on baked-carbonized functional flavors and konjac glucomannan (KGM) were prepared. The composite structure, morphologies on the surface and the cross section, porosity structures including mesoporous and macropore of the porous composite membranes were characterized, the tensile performance and aroma constituents through solid phase microextraction and hazardous substances adsorption as packed into the commercial cigarette were also studied. Results showed that all baked-carbonized functional flavors were carbonized into amorphous, and contained the groups of aromatic components like ≡C-H, C=O, C-O-C (aldehydes, esters), cross-linking achieved the entanglement of KGM segments by deacetylation. When compounded, KGM acted as the framework to build the 3D porous network structure, and the functional flavor powders were wrapped into the KGM layer. All porous composite membranes owned some mechanical strength and the internal porosity over 90%, the mesopores and the macropores were ranged with 5–50 nm and 20–255 µm, respectively, which was satisfied for gas flowing and harmful substances adsorption. Aroma and resulting abundance of extracted constituents changed with timing, which equipped the membranes with a comprehensive aroma feeling. Among them, the membrane prepared with the raw material of dark plum showed a better comprehensive performance, especially it could significantly reduce the contents of harmful HCN and phenol in cigarette during smoking.
... [5] Non-starch polysaccharides are also beneficial to the body in the acute to chronic gut malfunctioning including specially constipation by inducing GI peristalsis, which absorbs toxins from the stomach and facilitates their excretion. [6] Additionally, these non-starch polysaccharides help enhance gut microflora by serving as a prebiotic in the human GI tract. In many clinical trials and efficacies, DFs are claimed as supernatural food which plays a significant role to combat various metabolic syndromes. ...
The current research aimed to extract and characterize arabinoxylans (AX) from psyllium seeds husk for their nutritional and structural properties. For this purpose, psyllium husk (PH) was procured from the local market and subjected for the nutritional profile, dietary fiber (DF) composition, and AXs extraction. The extraction of AXs from psyllium seed husk was done through enzymatic method and Fourier transform infrared (FTIR) spectroscopy was used for its structural characterization. Further, the antioxidant activity of AXs was also elucidated using ferric reducing antioxidant power (FRAP) and diphenyl picryl hydrazyl (DPPH) assays. Results showed that psyllium seed husk is a good source of DFs (61.5 ± 2.6%) and the proximate composition including moisture, ash, crude fat, crude protein, crude fibers, and Nitrogen free extract (NFE) was 4.9 ± 0.01, 4.1 ± 0.01, 1.2 ± 0.01, 3.9 ± 0.05, 20.23 ± 0.4 and 78.2 ± 4.01 g/100 g, respectively. Furthermore, AXs content was 68.29 ± 3.4 g/100 g of PH. Different monosaccharides including xylose, arabinose, rhamnose, glucose, and galactose contents in PHAXs were 64.23 ± 1.04%, 13.38 ± 0.16%, 1.43 ± 0.04%, 1.89 ± 0.05%, and 3.64 ± 0.07%, respectively. FTIR absorption peaks from 900 to 1100 cm⁻¹ showed spectra of AXs with the highest peak from 980 to 1015 cm⁻¹ reflecting arabinose and xylose ratio. Additionally, the substitution positions on the xylan backbone were 2800–3400 cm⁻¹ of O-H stretching vibrations and peaks of C-H stretching at 2853 and 2923 cm⁻¹. The antioxidant activity of PHAXs exhibited that the FRAP value of extracted AXs was 1.39 ± 0.06 μmol Fe2+/g and the DPPH value was 3.01 ± 0.15 Trolox mg/g. It is depicted that PH is a good source of AXs (non-starch polysaccharide) with better antioxidant potential.
... Due to their anti-diabetic activities, many natural polysaccharides have attracted considerable interest. Konjac glucomannan (KGM) is a polysaccharide isolated from the tubers of Amorphophallus konjac that can reduce the level of glucose in the blood [9]. Acanthopanax senticosus polysaccharide ASP was purified and found to significantly increase serum insulin levels while decreasing fasting blood glucose (FBG) levels [10]. ...
In this study, water-soluble natural polysaccharides were extracted from the stems of Houttuynia cordata Thunb (HCPS). The optimization of the hot water extraction process using response surface methodology (RSM), and the extraction factors, were analyzed by multiple stepwise regression analysis and Pearson analysis. Then, the structural characterization and biological activity of the HCPS were investigated. The results indicated that the maximum extraction yield (2.43%) of the HCPS was obtained at the optimal condition (extraction temperature for 90 °C, extraction time for 5 h, solid-liquid ratio for 1:30 g/mL). The extraction temperature was determined to be the primary factor influencing the extraction yield. The HCPS molecules had an average molecular weight of 8.854 × 103 kDa and were primarily of mannose (Man), rhamnose (Rha), glucuronic acid (GlcA), galacturonic acid (GalA), glucose (Glc), and xylose (Xyl). In addition, the backbone of the HCPS might consist of →6)-α-d-Glcp-(1→ and →6)-β-d-GalpA-(1→. The HCPS had no triple-helix structure. The scanning electron microscopy (SEM) results showed that the HCPS presented a smooth and uniform appearance, and some sheet and chain structures existed. Moreover, the HCPS exhibited significant anti-oxidant activity and inhibited the activity of α-amylase and α-glucosidase. These findings showed that HCPS might be developed into a potential material for hypoglycemia, and provides a reference for the development of Houttuynia cordata polysaccharide applications in food.
... Glucomannan is basically a straightchain polymer with just an 8:5 ratio of -(14)-linked D-mannose and D-glucose. [15][16] ...
... KGM has gained popularity due to its reduced viscosity, better hydrophily, and beneficial physiological activities (Jiang et al., 2018). KGM has already been demonstrated to enhance health-related quality of life indices (Behera & Ray, 2016;Devaraj et al., 2019). These advantages may be especially crucial for those suffering from schizophrenia, who may be more prone to poor health-related quality of life and psychological healing (Jiang et al., 2018). ...
Objectives: effects of konjac glucomannan (KGM) in adults with schizophrenia. Method post feasibility trial with 20 participants with elevated blood glucose, blood pressure, and triglycerides. Intervention konjac glucomannan for 1 to 1.5 h, 1 tablet times every day for 4 weeks, and were encouraged to practise the exercises at home. Main Outcome Measures Indicators of blood pressure, fasting blood glucose, triglycerides, and schizophrenia symptoms. Results: There was high acceptability and good adherence. There were significant improvements in four indicators of metabolic syndrome including; Cholesterol (p,0.037), systolic (p,0.037) and diastolic blood pressure (p,0.869), as well as in GDP (p,0.004), schizophrenia symptoms (p,0.000). Conclusions: The program was feasible and acceptable, and participants' physiologic and physiological variables continued to improve. A larger controlled trial is now required to confirm these encouraging preliminary findings.
... KGM has gained popularity due to its reduced viscosity, better hydrophily, and beneficial physiological activities (Jiang et al., 2018). KGM has already been demonstrated to enhance health-related quality of life indices (Behera & Ray, 2016;Devaraj et al., 2019). These advantages may be especially crucial for those suffering from schizophrenia, who may be more prone to poor health-related quality of life and psychological healing (Jiang et al., 2018). ...
Objectives: effects of konjac glucomannan (KGM) in adults with schizophrenia. Method post feasibility trial with 20 participants with elevated blood glucose, blood pressure, and triglycerides. Intervention konjac glucomannan for 1 to 1.5 h, 1 tablet times every day for 4 weeks, and were encouraged to practise the exercises at home. Main Outcome Measures Indicators of blood pressure, fasting blood glucose, triglycerides, and schizophrenia symptoms. Results: There was high acceptability and good adherence. There were significant improvements in four indicators of metabolic syndrome including; Cholesterol (p,0.037), systolic (p,0.037) and diastolic blood pressure (p,0.869), as well as in GDP (p,0.004), schizophrenia symptoms (p,0.000). Conclusions: The program was feasible and acceptable, and participants' physiologic and physiological variables continued to improve. A larger controlled trial is now required to confirm these encouraging preliminary findings.
... Punia et al. [49] said that wheat flour had phenolic acids including ferulic, caffeic, and p-coumaric acid. Moreover, the presence of TFC in the K0L0 sample is thought to be due to the presence of a thiol group in egg white, which is able to chelate metal ions and is able to be conjugated with saccharides [50], as well as the 3,5-diacetyltambulin compounds from stink lily flour [51]. Meanwhile, the TFC and TPC values in the K2L2 sample were dominantly contributed to by the presence of phytochemical compounds in the pluchea tea extract. ...
The study aims to determine the effect of the proportion of κ-carrageenan and the hot water extract of pluchea leaf tea on the quality and sensory properties of stink lily wet noodles. The research design is a randomized block design with two factors, i.e., the difference in the proportion of κ-carrageenan (K) (0, 1, 2, and 3% w/w) and the addition of the hot water extract of the Pluchea indica Less leaf tea (L) (0, 15, and 30% w/v), with 12 treatment levels (K0L0, K0L1, K0L2, K1L0, K1L1, K1L2, K2L0, K2L1, K2L2, K3L0, K3L1, K3L2). The data are analyzed by the ANOVA at p < 5% and continued with the Duncan’s multiple range test at p < 5%, and the best treatment was determined by the spider web method based on sensory assay by a hedonic method. The proportions of κ-carrageenan and the concentration of pluchea tea extract had a significant effect on the cooking quality and sensory properties. However, the interaction of the two factors affected the swelling index, yellowness (b*), chroma (C), hue (h), total phenol content (TPC), total flavonoid content (TFC), and DPPH free radical scavenging assay (DPPH). The best treatment of wet noodles was K2L0, with a preference score of 15.8. The binding of κ-carrageenan and phenolic compounds to make a networking structure by intra- and inter-disulfide bind between glucomannan and gluten was thought to affect the cooking quality, sensory properties, bioactive compounds (TPC and TFC), and DPPH.
... Konjac glucomannan (KGM) known for the remarkable gel-forming capacity is a food hydrocolloid extracted from tubes of Amorphophallus konjac C. Koch, which has increasing worldwide popularity recently due to its physiological activities and health benefits (Devaraj, Reddy, & Xu, 2019). Chemically, KGM is composed of β-1,4-linked D-mannosyl and Dglucosyl residues at a molar ratio of (1.5 -1.7): 1.0 with a small degree of β-1,3-branching linked at the C-3 position of mannose. ...
Utilizing ethanol in konjac glucomannan (KGM) gelation has important food processing applications. Typically, ethanol positively impacts the formation of low-alkali KGM gels and dramatically changes their physical properties, but the role of ethanol on the aggregation of KGM chains and the resultant gelation is less well understood. This study presents the distinct microstructures of low-alkali KGM gels incorporating ethanol. The fibril diameter and mesh size were determined to be 262.3±22.3 nm and 2.680±0.035 μm in average, contributing to a higher degree of anisotropy of such a gel network. Ethanol favors intermolecular aggregation by increasing the Rg of small-sized aggregates to 2.10 nm. The FTIR and temperature-cycled rheological studies suggest there are hydrophobic interactions stabilizing the gel network with the assistance of hydrogen bonds. The spatial confinement of deacetylated KGM chains as the solvent quality deteriorates by incorporating ethanol may arrange the aggregation and induce the structural reorganization in gel formation.
... Hence, adding KF could be a possible way to achieve high-quality forage rape silage by inhibiting the water activity. Currently, KF or KGM is generally used as a food additive or dietary supplement because of its considerable potential for enhancing human and animal health [15]. However, little is known about the effectiveness of KF as a silage additive. ...
To obtain high-quality silage and better understand the mechanism underlying silage fermentation, a study was conducted to investigate the effects of konjac flour (KF), Lactiplantibacillus plantarum (LP) and their combination on fermentation quality, aerobic stability, and microbial community of high-moisture forage rape after 60 days of ensiling. Results showed that the KF and LP treatments increased the lactic acid content, decreased the pH value, and inhibited the production of butyric acid in ensiled forage rape (p < 0.05). The additives also altered the bacterial community of forage rape silages, showing reduced Shannon and Simpson indexes (p < 0.05), while the abundance of desirable Lactobacillus was increased, and the abundance of undesirable bacteria, such as enterobacteria and clostridia, was decreased (p < 0.05). In addition, their combination significantly improved the aerobic stability (96 h vs. 28 h, p < 0.05) and exhibited notable influence on the bacterial community, with the highest abundance of Lactobacillus. These results indicated that KF and LP improved the silage quality of high-moisture forage rape, and their combination displayed a beneficial synergistic effect.
... Its tubers can be used to extract a low-cost hydrocolloid gum made primarily of glucomannan, a soluble dietary fibre. By enhancing the stability of encapsulated materials and ensuring that they efficiently accomplish their objectives, for microbial cell immobilisation, as drug carriers and a material to be used for encapsulation, hydrogels can be applied that are konjac-based gum (Devaraj et al. 2019). ...
Probiotics have acquired an unavoidable role in human life which upon consumption in sufficient quantity confer numerous therapeutic benefits. Probiotics evidently affect the immune modulation and aid in the prevention of different types of cancers, including colon, breast, gall bladder, etc. Lactic acid bacteria (LAB) are recognised probiotics because they offer a vast range of benefits mainly in host nutrition and health. The most prominent probiotic strains of LAB include members of the genus Lactobacillus, Pediococcus, Bifidobacterium, and Enterococcus. Microencapsulation provides complete protection and an incredible tendency for shielded probiotics to overcome all of the challenges of the harsh gastric environment. Well developed and established practices of microencapsulation involve emulsion, spray-drying, and extrusion. Cell encapsulation is emerging as a viable alternative for incorporating probiotics into a range of food matrices. The international market for nutritional and probiotic foods are rising exponentially. Bacteriocins, immunomodulatory compounds, antimicrobial compounds, aromatic compounds, enzymes, and short-chain fatty acids are all produced by probiotic strains with different beneficial effects in the food industry to human health.
... The biological functions of polysaccharides (both digestible and indigestible) are closely linked to their metabolism in the digestive tract from the stomach to colon (Gullon et al., 2015), but the mechanism of their action is not clear. In addition, there are growing evidences that the large polysaccharides are hard to be digested by the gastrointestinal media but can be readily digested by the intestinal microbiota (Devaraj et al., 2019). The polysaccharides can be degraded and utilised by the intestinal microbiota in large intestine to produce different metabolites, such as short chain fatty acids (SCFAs) (Lovegrove et al., 2017). ...
In vitro digestion models are widely used to study the structural changes, digestion and release of food components under simulated gastrointestinal conditions. As compared to the in vivo digestion tests, the in vitro digestion reflects the digestion and utilisation of food after ingestion and has the advantages of being time consuming, inexpensive, reproducible and free from moral and ethical restrictions. This study reviewed the current research studies on the in vitro simulated digestion of polysaccharides conducted in the last 5 years and focused on the oral, gastric and intestinal digestion models, with the aim of providing a basis for the further testing of changes in the content, structure and active ingredients of polysaccha-rides before and after digestion.
... Konjac glucomannan (KGM) attracts our attention as it is rich in actively functional groups (−OH) [15]. KGM comprises β-D-glucose and β-D-mannose at a molar ratio of 2:3 or 1:1.16, which the molecular chain is formed by β-1,4 glycosidic bonds in the main chain and β-1,3 glycosidic bonds in the side chains [16,17]. ...
Customarily, retarders serve as the setting time regulators of cement-based composites to meet the demands of various construction environments. However, the limited ability to adjust the setting time restricts the application of polysaccharides in special environments. In this study, we reported a naturally high-efficiency retarder, konjac glucomannan (KGM), and studied the mechanism of its effect on the hydration of ordinary Portland cement. Incorporating KGM could significantly prolong cement hydration without strength damage. Furthermore, the active hydroxyl group (-OH, rich in KGM) could chelate with Ca2+ (released from cement hydration) to form a cross-linking network, which is adsorbed on the surface of cement clinker, thereby being conducive to delaying the process of cement hydration and reducing the heat of hydration. The findings of this study are critical to the ongoing efforts to develop polysaccharide-cement-based composite materials for application in various special environments.
... Glucomannan is another water soluble polysaccharide but with repeating β-1,4-linked D-mannose units as the polymer backbone with branched D-glucose linked to mannose by β-1,6 glycosidic bonds (Devaraj, Reddy, and Xu 2019). One of the most studied glucomannan is Konjac glucomannan (KGM) that is extracted from Amorphophallus konjac, a plant often found in subtropical regions. ...
Phenolics have been shown by in vitro and animal studies to have multiple pharmacological effects against various colonic diseases. However, their efficacy against colonic diseases, such as inflammatory bowel diseases, Crohn's disease, and colorectal cancer, is significantly compromised due to their chemical instability and susceptibility to modification along the gastrointestinal tract (GiT) before reaching the colonic site. Dietary fibers are promising candidates that can form phenolic-dietary fiber composites (PDC) to carry phenolics to the colon, as they are natural polysaccharides that are non-digestible in the upper intestinal tract but can be partially or fully degradable by gut microbiota in the colon, triggering the release at this targeted site. in addition, soluble and fermentable dietary fibers confer additional health benefits as prebiotics when used in the PDC fabrication, and the possibility of synergistic relationship between phenolics and fibers in alleviating the disease conditions. The functionalities of PDC need to be characterized in terms of their particle characteristics, molecular interactions, release profiles in simulated digestion and colonic fermentation to fully understand the metabolic fate and health benefits. This review examines recent advancements regarding the approaches for fabrication, characterization, and evaluation of PDC in in vitro conditions.
During the last decade, an increased attention has emerged on circular economy focused to improve simultaneously the environment, economy, and society for a sustainable development. In this context, biorefinery systems act as tactical mechanisms for the transition of a circular bioeconomy, since these systems can produce multiple high-value products, among biofuels, including food and feed products, biochemicals, and biomaterials, coming from diverse biomasses through the integration of useful conversion technologies. Agricultural activities are responsible for the overaccumulation and overproduction of lignocellulosic waste (e.g., bagasse, branch, leaves, wheat stover, fruit and vegetable seeds and peels). Such waste biomasses are abundant and could be considered as versatile natural resources for the obtention of this kind of products with high industrial demand. Thus, exploiting these lignocellulosic materials for the obtention of bioenergy and biochemicals, among other products, under biorefinery approach is a key objective for the transition of a well-succeeded circular bioeconomy. In this chapter, we focus on the principal constituents such as cellulose, hemicellulose, and lignin present in the lignocellulosic biomasses. Each component has its unique characteristics, and their valorization depends on effective biomass treatment. This chapter presents traditional and novel treatment methods for agricultural lignocellulosic biomass valorization and their potential applications.
Konjac glucomannan (KGM) can act as a food additive to improve the quality of dough. The effects of KGM on the aggregation patterns and structural properties of weak, middle, and strong gluten were studied. We found that with a higher proportion of KGM substitution (10%), the aggregation energy of middle and strong gluten became lower than the control samples, while exceeding the control for weak gluten. With 10% KGM, aggregation of glutenin macropolymer (GMP) was enhanced for weak gluten, but suppressed for middle and strong gluten. The α-helix transferred to β-sheet in weak, but caused more random-coil structures for middle and strong gluten induced by 10% KGM. With 10% KGM, the network for weak gluten became more continuous, but severely disrupted for middle and strong gluten. Thus, KGM has distinct effects on weak, middle, and strong gluten, which related to the alteration of gluten secondary structures and GMP aggregation pattern.
Konjac is a high-quality dietary fiber rich in β-glucomannan, which has been reported to possess anti-obesity effects. To explore the effective components and the structure-activity relationships of konjac glucomannan (KGM), three different molecular weight components (KGM-1 (90 kDa), KGM-2 (5 kDa), KGM-3 (1 kDa)) were obtained, and systematical comparisons of their effects on high-fat and high-fructose diet (HFFD)-induced obese mice were investigated in the present study. Our results indicated that KGM-1, with its larger molecular weight, reduced mouse body weight and improved their insulin resistance status. KGM-1 markedly inhibited lipid accumulation in mouse livers induced by HFFD by downregulating Pparg expression and upregulating Hsl and Cpt1 expressions. Further investigation revealed that dietary supplementation with konjac glucomannan at different molecular weights caused β-diversity changes in gut microbes. The potential weight loss effect of KGM-1 maybe attributed to the abundance of changes in Coprobacter, Streptococcus, Clostridium IV, and Parasutterella. The results provide a scientific basis for the in-depth development and utilization of konjac resources.
The pH-sensitive hydrogel consisting of carboxymethylated konjac glucomannan (CMKGM) and sodium trimetaphosphate (STMP) was prepared for a potential intestinal targeted delivery system. Both the CMKGM and the CMKGM hydrogel were characterized by FT-IR spectra, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The Congo red and atomic force microscope (AFM) results showed a coil-to-helix transition of CMKGM in alkaline conditions with the degree of substitution (DS) increased from 0.20 to 0.49. Rheological measurements indicated that the DS and the STMP content collectively influence the mechanical stiffness and swelling properties of the obtained hydrogels. In addition, the swelling behavior of the hydrogels revealed that they were sensitive to pH value changes and were following a Korsmeyer-Peppas gastrointestinal release behavior, indicating that the release was controlled by non-Fickian diffusion. Furthermore, all the results suggested that the prepared pH-sensitive hydrogel may serve as a potential biomaterial for the intestine-targeted delivery system.
The effect of konjac glucomannan (KGM) on the stability and digestion characteristics of xanthan gum/lysozyme nanoparticles (XG/Ly NPs) stabilized Pickering emulsions was investigated. Results indicated that the high viscosity of KGM prompted the particles to be adsorbed toward the interface, which decreased the particle size and increased the stability of emulsions. As the concentration of KGM increased, the G' and G″ of emulsions became larger and approached a "solid-like" state. When the KGM concentration was ≥0.2 %, the large amplitude sweeps of the emulsion exhibited a "weak strain overshoot". The network structure formed by KGM molecular chain and particles was intertwined around the droplets to form a polysaccharide layer and fibrous network structure. Emulsions containing KGM showed a "spider web" epidermal network pattern. It was found by illumination for 4 h that samples with 0.2 % KGM concentration increased the retention of β-carotene by 18.74 %. KGM decreased the release rate of fatty acids and bioaccessibility by hindering bile salt and lipase adsorption.
Porang is a tuber plant that has potential and prospects to be developed in Indonesia because it contains high levels of glucomannan. Propagation in vitro is required but has obstacles in the form of failure rates due to contamination. This study aimed to examine the effect of media type and sterilization method on the growth of porang ( Amorphophallus muelleri ) shoots in vitro. Parameters observed included shoot emergence day, number of shoots, shoot color, percentage of contamination, growth and development of explants. The data analysis used in this research is descriptive analysis. The results of this study indicate that the treatment of planting media affects the growth of porang shoots. The best treatment combination was found in the treatment of sterile cotton media with 1 minute sterilization which showed a contamination level of 3%, the number of shoots was 8, the average day of shoots appeared at 7 DAP, the color of the shoots was reddish green. Sterilization by soaking bulbil longer can reduce the growth of the number of shoots, increasing contamination.
Konjac glucomannan (KGM)/agar blend films were obtained by casting at different drying temperatures (40 °C, 50 °C, 60 °C, 70 °C, and 80 °C) at an industrial scale. The effects of the drying temperature on the microstructure, mechanical, and water barrier properties of the films were investigated. The results showed that lower temperatures (40 °C, 50 °C, and 60 °C) led to enhanced H-bond interactions between KGM and agar and more ordered structures of KGM/agar films, as evidenced by FTIR and X-ray analysis. Correspondingly, the mechanical properties were altered with the film's structure and showed significant differences (p < 0.05) at various drying temperatures. Moreover, the drying temperatures from 40 °C to 80 °C had no significant influence (p > 0.05) on the water vapour permeability of the films. The film dried at 60 °C showed significantly higher water contact angle and lower swelling ratio and solubility than the other films. Additionally, the drying temperature of 60 °C gave the highest thermal degradation temperature. Therefore, 60 °C was recommended for KGM/agar film production. This research guides the selection of the optimal drying temperature for edible film production.
Konjac glucomannan (KGM) is a herbal medicine with benefits in appetite control, body weight and biochemical parameters in overweight individuals. The objective of our work was to evaluate the effect of the consumption of gummy candy enriched with KGM on appetite, to evaluate anthropometric data, biochemical and oxidative stress markers in overweight individuals. Forty-two participants aged 18 to 45 years completed our randomized, double-blind, placebo-controlled clinical trial. Participants were randomly assigned to consume for fourteen days, 2 candies per day, containing 250 mg of KGM or identical-looking placebo candy with 250 mg of flaxseed meal, shortly after breakfast and dinner. As a result, we observed that there was a reduction in waist circumference and in the intensity of hunger/satisfaction of the participants who consumed KGM for fourteen days, and we believe that a longer consumption time as well as an increase dose of KGM contribute to even more satisfactory body results.
A facile post-gelation soaking strategy for producing low-alkaline konjac glucomannan (KGM) gels was investigated in this work. The dealkalization kinetics of soaking alkali-induced gels in citric acid (CA) solutions was determined. A comparison of sensory, textural, and water holding properties was made between untreated and post-soaking gels. Post-gelation exposure to acid took less time for lowering the gel pH at higher CA concentrations, eliminated the unattractive flavor of KGM gels and endowed them a higher hardness and breaking force. Comparatively, the whiteness of post-soaking gels was increased by 3.8 %–13.1 % with volume being decreased by 4.9 %–8.6 %, while the discrepancies were less apparent after a long-term storage. Low-alkaline gels treated by 4 g/L CA shared similar textural features with conventional KGM gels. Despite the difference in water distribution and water holding capacity of KGM gels, the syneresis of resultant low-alkaline KGM gels was not significantly affected.
Wound dressing with good biocompatibility and bioactivity is urgently needed in wound treatment. Herein, we present a biocompatible hydrogel based on a natural polymer, konjac glucomannan (KGM), and explore its...
The exceptional network assembly of natural polysaccharides/proteins-based hydrogels offers favorable biological characteristics and tunable physical properties making them ideal candidates for food and biomedical applications. Rheological analysis can provide quantitative information insights into the assembled network, which are critical for determining hydrogel properties and their suitability for food or biomedical use. This review introduced some concepts of rheology and brought together the hydrogels based on more than ten natural biopolymers, such as starch, pectin, gellan, xanthan, alginate, gelatin, carrageenan, soy protein, casein protein, whey protein, agar, cellulose, konjac glucomannan, and their related rheological studies. In addition, combined with our previous work, the effect of diverse cross-linking strategies on rheology and the role of various rheological characteristics (such as modulus variations, shear behavior changes, thixotropy and creep recovery capabilities, etc.) in gel design and application (such as 3D printing-based foods, active ingredients carrier, etc.) were also discussed.
Konjac glucomannan (KGM) gel has attracted widespread interest in the field of food. However, the low texture properties of gel limit its further application. In this study, the effect of KGM powder under different processing times (8 h, 12 h, 24 h and 48 h) and temperatures (4 °C, −18 °C, −80 °C) on the texture properties of gels were investigated. According to result of texture profile analysis (TPA) and puncture test, the gel prepared by pretreatment showed good texture characteristics. The gel prepared by freezing KGM powder at −18 °C for 8 h has the best gel strength in the sample, which is 1.6 times that of native KGM. The molecular weight of KGM decreased significantly after pretreatment (from 12.30 × 10⁵ Da to 0.29 × 10⁵ Da). In addition, low temperature and freezing treatment can influence the rheological behavior and regulate water composite in gel. According to experimental result, it can be attributed to that low temperature and the growth of ice crystal can make structures denser, promote KGM molecular chain entangled and increase the number of hydrogen bond. This study provides a convenient and effective method for improving the gel properties.
Unlabelled:
In this study, a natural-based gelling agent comprised of blended flax seed gum (FSG), konjac glucomannan (KG), and agar gel (AG) was developed for application to control the textural properties of foods. The compound gels, including FSG, KG, and AG, were investigated to determine their moisture affinity, including minimum gelling concentration, water binding capacity, water soluble index, and swelling power. In addition, we analyzed the rheological properties of the compound gel through texture analysis, frequency sweep, and creep and recovery. The microstructure of the compound gel was identified and compared with the viscoelastic properties of the gel. Overall, these results showed that the F4K6 (4:6:2 of FSG:KG:AG) could serve as an excellent gelling agent, which endowed food gel with the promoted elastic properties, water capacity, and rigid surface morphology. This work suggests that novel gelling agents, including FSG, KGM, and AG, successfully prepared food gels with improved physicochemical properties.
Supplementary information:
The online version contains supplementary material available at 10.1007/s10068-022-01179-9.
The quality and flavor of scallops changes during the fresh dry rehydration process. In order to control the changes after rehydration, a scallop pretreatment method was adopted. The pretreatment method involved impregnating fresh scallops with 0.2 g/100 mL konjac glucomannan (KGM), carrageenan (CA), and sodium alginate (SA) before the drying and rehydration process. After rehydration, the KGM treated samples had better water retention and the highest betaine content. The CA treated samples had a deepened yellow color and the highest content of flavoring amino acids (FAA) and inosine monophosphate (IMP). What’s more, a total of 77 volatile compounds were detected, with a maximum of 15 esters. The highest proportion in the four groups was eugenol, followed by n-hexadecanoic acid, methyl hexadecanoate etc. The SA group had no significant contribution in terms of quality and taste. The samples pretreated with KGM had the best quality, and those pretreated by CA had the best flavor.
PurposeDietary fibers and hypoglycemic drugs can be used concomitantly in the treatment of diabetes mellitus. We aimed to perform this review in order to evaluate whether scientific evidence is available regarding the interaction between these components and whether these interactions alter drug absorption.Methods
We conducted a search of the literature for controlled clinical trials that evaluated the occurrence and clinical relevance of interactions between dietary fibers and hypoglycemic drugs. Six databases were searched from inception to April 20, 2020 and trials were eligible for inclusion if they measured changes in drug absorption parameters.ResultsIn three studies, there were interactions between dietary fibers and hypoglycemic drugs, causing alterations in drug absorption. The other two studies had no significant changes in absorption pharmacokinetic parameters.Conclusions
The physicochemical characteristics of the dietary fiber used, the chemical structure of the drug, and the pharmaceutical form administered are determining factors for the occurrence of alterations in drug absorption.
Deacetylated konjac glucomannan (DKGM)/calcium pectin (Ca-PEC) composite films were prepared by calcium hydroxide to realize deacetylation of konjac glucomannan (KGM) and the crosslinking of pectin at the same time. Fourier transform infrared spectroscopy (FTIR) indicates that there are intermolecular hydrogen bond and crosslinking structure between DKGM and Ca-PEC. The physical properties of the composite films are characterized by mechanical properties, water vapor permeability (WVP), swelling degree (SD), water solubility (WS), thermogravimetry (TG) and Opacity. The results exhibit that deacetylation of KGM and crosslinking structure of pectin reduce the swelling degree and water solubility of the films, as well as improve its thermal stability and tensile strength. These are attributed to enhanced intermolecular interactions, more compact entanglement of molecular chains and more solid spatial network structures. When pectin content is 40%, the combination property of DKGM / Ca-PEC composite film is the best.
INTRODUÇÃO:
O excesso de peso e a obesidade são considerados uma problemática de saúde, podendo ter repercussões na mortalidade e qualidade de vida dos indivíduos. O glucomanano é um componente significante do cormo de konjac, proveniente da planta designada por Amorphophallus konjac. É considerado uma fibra dietética fermentável solúvel, que forma géis, e o seu papel como suplemento alimentar tem sido estudado nos últimos anos de modo a avaliar potenciais benefícios, nomeadamente no controlo ponderal.
OBJETIVOS:
Analisar a evidência científica existente sobre a suplementação de glucomanano no controlo de peso, bem como entender os riscos para a saúde inerentes ao seu consumo.
METODOLOGIA:
A pesquisa bibliográfica foi realizada nas bases de dados PubMed e ScienceDirect, recorrendo-se às palavras chave “glucomannan” e “weight”. Os resultados obtidos incluíram artigos, preferencialmente, dos últimos 10 anos, sendo que inicialmente foram selecionados pelo título, em seguida pelo resumo e por fim pela leitura completa dos mesmos.
RESULTADOS:
O glucomanano promove sensação de saciedade devido à sua capacidade de absorção de água, potenciando a motilidade intestinal. A maioria das revisões analisadas verificou uma perda de peso significativa a curto prazo, em adultos com excesso de peso ou obesidade, no entanto um outro estudo com maior número de participantes, não verificou resultados positivos neste aspeto. Em crianças e adolescentes, os estudos são escassos não mostrando efeitos significativos na redução de peso. A dose recomendada com potenciais efeitos benéficos em adultos é de 3g/dia.
CONCLUSÕES:
Os ensaios futuros devem ter melhor qualidade metodológica. Assim sendo, apesar da recomendação de glucomanano para perda de peso parecer segura, esta não deve ser a primeira abordagem nem uma prioridade.
Background:
In the context of the increasing prevalence of overweight and obesity worldwide, satiety-enhancing foods may help people control their energy intake and weight. In this study, an advanced near-real human gastric simulator equipped with a dynamic in vitro human stomach-IV (DIVHS-IV) system was used to determine the gastric digestion and gastric retention ratio of konjac flour (KF)/sodium caseinate (SC) mixtures with different ratios.
Results:
The apparent viscosity, viscoelastic properties, confocal laser scanning microscopy (CLSM) of the digested products were collected and analyzed to further study the effect of SC on the physical properties of KF during digestion. The results showed that the addition of SC could enhance the effect of KF on delaying gastric emptying in vitro. Besides, the addition of SC was shown to weaken the effect of gastric juice on the dilution of gastric contents by forming SC gel blocks in the acid environment. In particular, the synergistic gastric emptying delaying effect was the strongest in the KF/SC mixture containing 1% KF and 8% SC, and obvious massive aggregates were observed.
Conclusion:
The combination of 1% KF and 8% SC was shown to synergistically delay gastric emptying and potentially enhance the sense of fullness. © 2022 Society of Chemical Industry.
Background
Dietary fibers, as mainly complex carbohydrates, offer various health benefits via modulating gut microbiota composition and promoting short chain fatty acids (SCFAs) production. However, the modern dietary habits are altered by reducing dietary fiber consumption and increasing intake of fat, sugar, and animal protein, thus adversely affecting our gut microbiota. This deficiency of dietary fibers is usually associated with an increasing risk of chronic diseases such as type 2 diabetes, cardiovascular diseases, and colorectal cancer.
Scope and approach
In this review, firstly we elaborately classified dietary fibers based on the definition by the European Food Safety Authority (EFSA), revealed the structure-activity relationship of dietary fibers, and up-dated carbohydrate active enzyme families (CAZyme). Furthermore, this review summarizes the available literature on the interaction between different types of dietary fiber, gut microbiota composition, and SCFA production, both in vivo and in vitro.
Key findings and conclusions
Dietary fiber-rich and WG-based diets offer a desirable nutritional intervention strategy by manipulating the composition and quality of microbiota to improve intestinal environment so as to promote host health.
Nano-selenium particles (SeNPs) are considered to have high biological activity and low toxicity, but their stability need to be improved. Konjac glucomannan (KGM) was introduced as a stabilizer for the preparation of SeNPs via ascorbic acid (AA)-sodium selenite (Na2SeO3) redox system in this study, the influence of reaction conditions on the formation of KGM-SeNPs was estimated and the preparation parameters were optimized via orthogonal experiment. It is found that KGM concentration and Se⁴⁺ concentration are the two most important parameters that affect the particle size and morphology of KGM-SeNPs, beside of the agglomeration promoted by higher temperature. The optimal product possessed spherical particles with a particle size of 50–150 nm, the selenium content in lyophilized supernatant and lyophilized precipitate were 38.17% and 19.19%, respectively, and infrared spectroscopy analysis showed KGM-SeNPs were mainly compounded by intermolecular electrostatic interaction. KGM-SeNPs exhibited inhibitory effects on Staphylococcus aureus but no on Escherichia coli and Penicillium, strong scavenging activity against ABTS•⁺ and DPPH•, strong reduction activity on Fe³⁺ and low cytotoxicity in Caco-2 cells. These results indicated that KGM-SeNPs were expected to be developed as a food-grade antioxidant or selenium supplement in food and pharmaceutical product applications.
Objective:
Glucomannan is a dietary fiber that slows the absorption of carbohydrates and suppresses appetite, thereby reducing blood glucose. This meta-analysis sought to examine the effect of glucomannan supplementation on Fasting Blood Glucose (FBG) and Postprandial Glucose (PPG) in adults.
Method:
We searched PubMed, and SCOPUS databases, and Google Scholar from inception to May 2020, using relevant keywords. All randomized controlled clinical trials (RCTs) that examined the effect of glucomannan supplementation on FBG and PPG in adults were included. Weighted mean differences (WMD) and their 95% confidence interval (CI) were calculated using Stata. Subgroup analysis was used to discern possible sources of heterogeneity.
Results:
Overall, 6 trials were included, consisting of 124 participants. We found that glucomannan supplementation significantly reduced FBG (WMD): -0.60 mmol/L, 95% CI: -1.16, -0.05; P=0.03, but not PPG (WMD: -2.07mmol/L ; 95% CI: -5.09, 0.95; P=0.18), compared with controls group. We conducted subgroup analysis based on dosage and duration of intervention and health status of the population. Findings from subgroup analysis revealed a significant effect of glucomannan supplementation on FBG in diabetic patients (WMD: -1.28 mmol/L, 95% CI: -2.54, -0.02; P=0.04).
Conclusion:
Glucomannan supplementation can elicit significant reductions in FBG, but has no significant impact on PPG, in adults. More RCTs may find the exact effect of glucomannan on FBG and PPG.
Supplementary information:
The online version contains supplementary material available at 10.1007/s40200-022-00993-6.
Tibetan turnip (Brassica rapa L.) polysaccharide (TTP) is an active ingredient and has been studied for many years due to its biological effect. There are a few studies on its digestion properties and the regulation of the intestinal microbiota. In this study, the regulation of intestinal health by TTP was investigated in vitro and in vivo. The results showed that TTP was not degraded after simulated gastrointestinal digestion. When TTP was fermented by the gut microbiota, the content of short-chain fatty acids (SCFAs) and the relative abundance of Bifidobacterium, Catenibacterium increased; the relative abundance of Prevotella, Phascolarctobacterium decreased. The in vivo experiments showed that TTP could reduce the abundances of Muribaculaceae and enrich Lactobacillus. The results of KEGG indicated that TTP could promote arginine and ornithine metabolism, fructose and mannose metabolism, and lipopolysaccharide biosynthesis. These data showed that TTP exerted its prebiotic effect by regulating the intestinal flora and could be used for preventing disease and improving health by maintaining intestinal health.
Konjac glucomannan (KGM) has attracted extensive attention because of its biodegradable, non-toxic, harmless, and biocompatible features. Its gelation performance is one of its most significant characteristics and enables wide applications of KGM gels in food, chemical, pharmaceutical, materials, and other fields. Herein, different preparation methods of KGM gels and their microstructures were reviewed. In addition, KGM applications have been theoretically modeled for future uses.
Amorphophallus konjac (konjac) is one among the major vegetable (tuber) crops grown in Asian
countries. In China and Japan, it has been used as food and food additives for more than 1000
years. Over the last few decades, the purified konjac flour, commonly known as konjac
glucomannan (KGM), a dietary fiber hydrocolloidal polysaccharide, has been introduced as a
food additives as well as dietary supplement in many Asian and European countries. The present
article reviews the literature (up to January 2015) covering the development of various functional
foods, food additives from KGMs and their derivatives, Also, this review deals with global
nutritional aspects and value added products of konjac corm.The bioprocessing techniques such
as preparation, purification, extraction of KGM from konjac flour and methods to improve
quality of KGM are discussed.
Type 2 diabetes is a very prevalent chronic disease. Among dietary factors for its prevention and treatment, interest has grown in satiating fibre (konjac glucomannan) and spirulina. Our previous studies suggest that glucomannan itself and/or in conjunction to spirulina displayed hypolipemic and antioxidant effects when incorporated to squid surimi as functional ingredients. The present study aims to determine whether glucomannan- enriched or glucomannan plus spirulina-enriched squid-surimi improve plasma glucose and insulin levels in Zucker fa/fa rats fed a high saturated fat diet. Twenty four growing rats, divided into three groups, were given modified AIN-93M diets for seven weeks: 30% squid-surimi control diet (C), 30% glucomannan-enriched squid-surimi diet (G) and 30% glucomannan plus spirulina-enriched squid-surimi diet (GS). All rats became hyperglycemics and hyperinsulinemics, but G and GS diets induced significantly lower glucose levels (20%; p < 0.05) but did not modify insulinemia with respect to C diet. GS animals showed higher HOMA-D (p < 0.05) than C ones suggesting increased insulin availability. Plasma leptin and adiponectin decreased in G and GS vs. C group (p < 0.05). Adipose adiponectin increased significantly in G and GS vs. C rats (16-20 times, p < 0.01). Leptin in adipose tissue was higher in GS vs. G group (p < 0.05). In conclusion, both glucomannan-diets were able to reduce hyperglycemia and increase adipose tissue adiponectin levels in fa/fa rats, suggesting an anti-hypertrophic and insulin-sensitizing adipokine effect in this tissue. Spirulina inclusion increased insulin availability. Although results are promising, the utility of consuming glucomannan surimis as part of usual diets demands future studies.
Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.
Purpose:
Pulverized konjac glucomannan (PKGM) is a natural biologically active compound extracted from konjac, a Japanese traditional food. In the present study, we investigated the role of PKGM in intestinal immunity in a mouse model of oxazolone (OXA)-induced colitis.
Methods:
C57BL/6(B6) mice were fed PKGM or control food from 2 weeks before the induction of OXA colitis. Body weight change, colon length, and histological change in the colon were examined. The mononuclear cells were purified from colon and stimulated with PMA/ionomycin. The levels of TNF-α, interferon (IFN)-γ, interleukin (IL)-4, and IL-13 from the supernatant were measured by ELISA.
Results:
Oral administration of PKGM prevented the body weight loss and shortening of colon length associated with OXA-induced colitis. Histological analysis revealed that the colonic inflammation was improved by the administration of PKGM. The levels of IL-4 and IL-13, the critical inflammatory cytokines in OXA colitis, derived from mononuclear cells from the lamina propria of the colon were significantly suppressed by PKGM administration. PKGM-fed mice showed a significantly lower IL-4/IFN-γ ratio in the colonic lamina propria compared with that in control-fed mice. Fluorescence-activated cell sorting analysis revealed that natural killer (NK) 1.1(+) T cells in the liver were significantly decreased in PKGM-fed mice. Finally, the preventive role of PKGM in OXA-induced colitis was not observed in invariant natural killer T cell-deficient mice.
Conclusions:
PKGM ameliorated OXA-induced colitis in mice. This effect is associated with a decreased population of NK1.1(+) T cells and induction of Th1-polarized immune responses.
Clinical features similar to diabetes mellitus were described 3000 years ago by the ancient Egyptians. The term diabetes was first coined by Araetus of Cappodocia (81-133AD). Later, the word mellitus (honey sweet) was added by Thomas Willis (Britain) in 1675 after rediscovering the sweetness of urine and blood of patients (first noticed by the ancient Indians). It was only in 1776 that Dobson (Britain) firstly confirmed the presence of excess sugar in urine and blood as a cause of their sweetness. In modem time, the history of diabetes coincided with the emergence of experimental medicine. An important milestone in the history of diabetes is the establishment of the role of the liver in glycogenesis, and the concept that diabetes is due to excess glucose production Claude Bernard (France) in 1857. The role of the pancreas in pathogenesis of diabetes was discovered by Meting and Minkowski (Austria) 1889. Later, this discovery constituted the basis of insulin isolation and clinical use by Banting and B
Drug delivery is the method or process of administering a pharmaceutical compound to achieve a therapeutic effect in humans or animals. For the treatment of human diseases, nasal and pulmonary routes of drug delivery are gaining increasing importance. These routes provide promising alternatives to parenteral drug delivery particularly for peptide and protein therapeutics. For this purpose, several drug delivery systems have been formulated and are being investigated for nasal and pulmonary delivery. These include liposomes, proliposomes, microspheres, gels, prodrugs, cyclodextrins, among others. Nanoparticles composed of biodegradable polymers show assurance in fulfilling the stringent requirements placed on these delivery systems, such as ability to be transferred into an aerosol, stability against forces generated during aerosolization, biocompatibility, targeting of specific sites or cell populations in the lung, release of the drug in a predetermined manner, and degradation within an acceptable period of time.
Konjac glucomannan is a kind of neutral polysaccharides with excellent biocompatibility and biodegradable activities. The recent studies on the applications of konjac glucomannan and its derivatives in pharmaceutical, bio-technical, fine chemical fields etc. were reviewed.
The controlled release of diclofenac sodium (DFNa) from a chitosan-oxidized konjac glucomannan (CTS-OKG) polymer film was studied. Konjac glucomannan (KGM) was initially oxidized by sodium periodate and then cross-linked to CTS via imine bonds (-C=N-) to form the new CTS-OKG copolymer. The DFNa loaded CTS-OKG polymers were characterized by Fourier transformed infrared spectroscopy (FT-IR) and X-ray diffractometry (XRD). Finally, the release profiles of DFNa from the CTS-OKG polymer matrices were evaluated in a simulated gastrointestinal fluid system comprised of two hours in simulated gastric fluid (SGF; pH 1.2) followed by 24 h in simulated intestinal fluid (SIF; pH 7.4). A 1:2:1 (w/w/w) ratio of CTS:OKG:DFNa prepared at room temperature for 3 hours gave the highest % encapsulation efficiency (EE) of 95.6 ± 0.6 and resulted in a minimal release of DFNa (<1% over 2 h) in SGF (pH 1.2) and a significantly improved sustained release in SIF (pH 7.4) with ~6% and 19% release over 8 and 24 h, respectively), some 15- and five-fold lower than that of the two commercial DFNa preparations, Diclosian and Voltaren. This formulation may be used for further study as a long term intestine controlled release drug model (at least 3 days).
Type 2 diabetes mellitus (T2DM) continues to be a major health problem worldwide. It is well known that T2DM is a metabolic disorder characterized by hyperglycemia, which arises from insufficient pancreatic insulin secretion, insulin resistance in peripheral tissues, and inadequate suppression of glucagon production. This suppression results in inadequate uptake, storage, and disposal of ingested glucose accompanied by elevated hepatic production of glucose and profound hyperglycemia. Notably, these pathophysiologic processes can progress to a clinically significant degree even in patients with impaired glucose tolerance. As researchers begin to unravel the genetic basis of T2DM, the gradual accumulation of genetic polymorphisms in multiple genes-rather than the mutation of a single "diabetes gene"-appears to be the driving force behind the increase in T2DM risk. Emergent therapies for the management of T2DM include incretin-based agents, which can effectively target two key processes in T2DM by augmenting insulin secretion and inhibiting glucagon production.
To assess the in vitro antibacterial, antifungal and cytotoxic activities of amblyone, a triterpenoid isolated from Amorphophallus campanulatus (Roxb).
Disc diffusion technique was used for in vitro antibacterial and antifungal screening. Cytotoxicity was determined against brine shrimp nauplii. In addition, minimum inhibitory concentration (MIC) was determined using serial dilution technique to determine the antibacterial potency.
Large zones of inhibition were observed in disc diffusion antibacterial screening against four Gram-positive bacteria (Bacillus subtilis, Bacillus megaterium, Staphylococcus aureus and Streptococcus pyogenes) and six Gram-negative bacteria (Escherichia coli, Shigella dysenteriae, Shigella sonnei, Shigella flexneri, Pseudomonas aeruginosa and Salmonella typhi). The MIC values against these bacteria ranged from 8 to 64 μg/ml. In antifungal screening, the compound showed small zones of inhibition against Aspergillus flavus, Aspergillus niger and Rhizopus aryzae. Candida albicans was resistant against the compound. In the cytotoxicity determination, LC(50) of the compound against brine shrimp nauplii was 13.25 μg/ml.
These results suggest that the compound has good antibacterial activity against the tested bacteria, moderate cytotoxicity against brine shrimp nauplii and insignificant antifungal activity against the tested fungi.
Several clinical trials have investigated the impact of glucomannan on plasma lipids, body weight, fasting blood glucose (FBG), and blood pressure (BP), but have yielded conflicting results and had only modest sample sizes.
The objective was to perform a meta-analysis of randomized controlled trials of glucomannan to better characterize its impact on plasma lipids, FBG, body weight, and BP.
A systematic literature search of MEDLINE, EMBASE, CINAHL, Web of Science, the Cochrane Library, and the Natural Medicines Comprehensive Database was conducted from the earliest possible date through November 2007. A random-effects model was used to calculate the weighted mean difference (WMD) and 95% CIs as the difference between the mean for the glucomannan and control groups. Standard methods for assessing statistical heterogeneity and publication bias were used.
Fourteen studies (n = 531) met the inclusion criteria. The use of glucomannan significantly lowered total cholesterol [weighted mean difference (WMD): -19.28 mg/dL; 95% CI: -24.30, -14.26], LDL cholesterol (WMD: -15.99 mg/dL; 95% CI: -21.31, -10.67), triglycerides (WMD: -11.08 mg/dL; 95% CI: -22.07, -0.09), body weight (WMD: -0.79 kg; 95% CI: -1.53, -0.05), and FBG (WMD: -7.44 mg/dL; 95% CI: -14.16, -0.72). The use of glucomannan did not appear to significantly alter any other study endpoints. Pediatric patients, patients receiving dietary modification, and patients with impaired glucose metabolism did not benefit from glucomannan to the same degree.
Glucomannan appears to beneficially affect total cholesterol, LDL cholesterol, triglycerides, body weight, and FBG, but not HDL cholesterol or BP.
To examine whether Konjac-mannan (KJM) fiber improves metabolic control as measured by glycemia, lipidemia, and blood pressure in high-risk type 2 diabetic patients.
A total of 11 hyperlipidemic and hypertensive type 2 diabetic patients treated conventionally by a low-fat diet and drug therapy participated. After an 8-week baseline, all were randomly assigned to take either KJM fiber-enriched test biscuits (0.7 g/412 kJ [100 kcal] of glucomannan) or matched placebo wheat bran fiber biscuits during two 3-week treatment phases separated by a 2-week washout period. The diet in either case was metabolically controlled and conformed to National Cholesterol Education Program Step 2 guidelines, while medications were maintained constant. Efficacy measures included serum fructosamine, lipid profiles, apolipoproteins, blood pressure, body weight, and nutritional analysis.
Compared with placebo, KJM significantly reduced the metabolic control primary end points: serum fructosamine (5.7%, P = 0.007, adjusted alpha = 0.0167), total:HDL cholesterol ratio (10%, P = 0.03, adjusted alpha = 0.05), and systolic blood pressure (sBP) (6.9%, P = 0.02, adjusted alpha = 0.025). Secondary end points, including body weight, total, LDL, and HDL cholesterol, triglycerides, apolipoproteins A-1, B, and their ratio, glucose, insulin, and diastolic blood pressure, were not significant after adjustment by the Bonferroni-Hochberg procedure.
KJM fiber added to conventional treatment may ameliorate glycemic control, blood lipid profile, and sBP in high-risk diabetic individuals, possibly improving the effectiveness of conventional treatment in type 2 diabetes.
Konjac glucomannan (KGM) is a major polysaccharide from the corm of Amorphophallus konjac. Native KGM has limited uses and has been chemically/physically/enzymatically modified to expand the range of functional properties. This mini-review summarises the recent advances of modifying KGM for diverse food and nonfood applications, focusing on the chemical and physical modifications. The chemical methods include substitution, grafting, cross-linking, oxidation, and deacetylation, whereas the physical modifications are electrospinning, microfluidic spinning, γ-irradiation, extrusion, and electric field processing. The modified KGM has been used in a range of different applications, including biodegradable film, emulsion, medical and pharmaceutical material, encapsulation and controlled release, fish feed and functional food ingredient, separation medium, aerogel, liquid crystal, absorbent for removal of pollutants in waste water, and so on. These KGM-based products tend to be biodegradable, biocompatible, and non-toxic with improved functional performance.
Amorphophallus paeoniifolius commonly known as "Jimikand", "Elephant foot yam" is one of the underutilized aroid of araceae family. It is one of the widely used tuberous, stout indigenous herbs used in ayurvedic medicine system for treating various human ailments. In recent years the popularity of complementary medicine has increased. The present review compiles the existing literature related to botanical description propagation, nutrient composition, phyto-chemical constituents, traditional uses, pharmacological actions and production of value added products of Amorphophallus paeoniifolius.
Konjac glucomannan ( KGM ) is a main component of natural materials konjac with broad biological function. This review summarizes the immuomodulatory effect of KGM on immune organ development, monocyte macrophage, natural killer cell, humoral immunity, cellular immunity, cytokines, and mucosal immunity.
Konjac-mannan has been suggested to exert a protective effect against visceral obesity. However, there is little knowledge about the effects of liquid konjac (LK) that is partially alkali gelled. The purpose of the present work was to evaluate the potential beneficial effects of a LK powder on obesity in mice. Male C57BL/6J mice were fed a high-fat diet supplemented with either 2.5 or 5% LK powder for 80 days. Growth parameters, abdominal fat content, serum biochemical markers, and hepatic lipid accumulations were measured. Dietary supplementation with LK resulted in decreased body weight gain and abdominal fat accumulation. Dose-dependent decreases were observed in accumulation of hepatic lipids and serum total cholesterol, leptin, insulin concentrations. The study findings indicated that LK had preventing effect against obesity, including the reduction of abdominal and hepatic lipid accumulation and serum parameters related to obesity.
Yogurt containing Bifidobacterium longum BB536 (designated as Bifidus yogurt) was administered to adult volunteers and its effects on the intestinal environment with reference to fecal microflora, ammonia levels, fecal characteristics (color, consistency) and defecation frequency were examined. Bifidus yogurt was manufactured by fermenting milk with B. longum BB536, Streptococcus thermophilus STH-450 and Lactobacillus delbrueckii subsp. bulgaricus LBU-108. Standard yogurt manufactured using only S. thermophilus STH-450 and L. delbrueckii subsp. bulgaricus LBU-108 was used as the control diet. Eleven women volunteers were assigned as subjects to test the effects of Bifidus yogurt on the intestinal environment. Thirty-nine women volunteers were assigned as subjects to test the effects on fecal characteristics and defecation frequency. The volunteers were each administered 100 g of standard yogurt per day for two weeks. After a two-week interval period, each subject was administered 100 g of Bifidus yogurt per day for the subsequent test period. The period of administration of Bifidus yogurt was 2 weeks for testing effects on the intestinal environment and 3 weeks for testing effects on fecal characteristics and defecation frequency. The administration of Bifidus yogurt was effective to increase the number and relative percentage of fecal bifidobacteria significantly. The fecal ammonia concentration tended to decrease and fecal organic acid content tended to increase. The defecation frequency was significantly increased by Bifidus yogurt. The color of the feces changed to yellow and the consistency changed to soft. The administration of Bifidus yogurt was effective to improve the intestinal environment, fecal characteristics and defecation frequency.
Frontal polymerization was used to prepare two kinds of superabsorbent polymers (SAP) called konjac glucomannan-acrylic acid-acrylamide (KGM-AA-AM) polymers and konjac glucomannan-acrylic acid-kaolin (KGM-AA-Kaolin) polymers. As preparation of KGM-AA-AM, it was found that features of front propagation including front velocity and maximum temperature (T(max)) were dependent on the amount of acrylamide, initiator (potassium persulfate) and water, which influenced characterization of final products in the former. However, in the other polymer system, when Kaolin/AA ratio reached 0.30, the highest water absorbency was obtained, 1941 gig in distilled water and 93 gig in physiological saline. That indicates kaolin is a potential material to enhance water absorbency of FP products.
Konjac glucomannan (KGM) was treated by a facile acid hydrolysis to fabricate KGM microcrystals. At the first day of hydrolysis, KGM microcrystals were formed. With the extension of hydrolysis time, the particle size of KGM microcrystals decreased from 45 μm to 15 μm. In addition, compared with native KGM, the morphological, physicochemical, crystalline, and thermal properties of KGM microcrystals changed significantly. SEM images showed the irregular shapes and rough surfaces of KGM microcrystals as well as the smooth surface of native KGM. FTIR measurements revealed the cleavage of carbonyl groups in KGM microcrystals. XRD curves clearly presented the crystalline structure of KGM microcrystals, and the relative crystallinity increased to approximately 50%. DSC analysis showed that microcrystals had a better thermal stability than native KGM, which could be preferably used as reinforcement in the biocompatible material at high temperature.
Oral colon targeting drug delivery system (OCDDS) is a highly effective formulation for drugs absorbed by colon, or to treat colonic diseases specifically. To obtain colon targeting, many pharmaceutical approaches have been studied, among which, taking advantage of specific degradation of excipients by colon enzymes is one of the most promising strategies. With properties of specific colon β-mannanase degradation, biocompatibility, gel-forming, low toxicity and high stability, konjac glucomannan (KGM) becomes a promising natural excipient for oral OCDDS. This paper summaries structure and properties of KGM, reviews achievements and prospects on KGM and modified konjac glucomannan about their application as pharmaceutic excipient for the OCDDS recently.
Carbohydrates may provide an alternative therapeutic approach for a number of digestive health disorders such as inflammatory bowel disease (IBD). The aim of this work was to characterise the tolerance and efficacy of low and high molecular weight konjac glucomannan hydrolysates within healthy volunteers and patients suffering from IBD and associated gut conditions. These conditions included constipation, Crohn's disease and ulcerative colitis. For general tolerance, fourteen patients participated whilst for the digestive disorder trial, there were twenty. Scores of taste/texture of the product, bowel movement, stool consistency, diarrhoea, existence/absence of blood in the faeces, abdominal pains, flatulence, vomiting, fever, improvement of life style after use, willingness to use in the future and clinician's statements about each patient's conditions before and after use were recorded. The results showed that the hydrolysates were tolerated well for patients with diarrhoea and had a significant improvement on bowel movement, stool consistency, abdominal pain and flatulence after ten days. With respect to effects on IBD, there was a significant health benefit after fourteen days of consumption for bowel movement, stool consistency, diarrhoea, existence/absence of blood in the faeces, abdominal pain, flatulence and vomiting. Most patients declared an improvement of their life style after consuming the hydrolysates. The use of konjac glucomannan hydrolysates as a therapeutic agent or adjunct to standard treatments could prove a successful tool for the treatment of a range of disorders; although large scale studies are required to characterise further the role of the carbohydrates.
In this study, the effects of konjac glucomannan (KGM) on Chinese noodles made from low-protein wheat flour were studied. Noodles were prepared from wheat flour/KGM blends by replacing low-protein flour at 1%, 2%, 3%, 4% and 5% with konjac glucomannan (KGM). The cooking and textural properties, microstructure and sensory characteristics were evaluated. KGM addition contributed to higher cooking yield and lower cooking loss for the resultant noodles. The sensory quality of KGM noodles was better than that of the control, although the control scored highest in stickiness. Sharp changes were observed around 5% substitution level in TPA parameters. Scanning electron microscopy (SEM) confirmed changes in noodle microstructure as KGM addition affect cooked starch granule structure and gluten network development. In general, noodles with 3% KGM were relatively desirable in textural properties and scored best in sensory evaluation, indicating the potential for improving textural defect of noodles prepared from low-protein wheat flour by using KGM.
The current study aims to develop and evaluate a colon-specific, pulsatile drug delivery system based on an impermeable capsule. A pulsatile capsule was prepared by sealing a 5-aminosalicylic acid rapid-disintegrating tablet inside an impermeable capsule body with a konjac glucomannan (KGM)–hydroxypropyl methylcellulose (HPMC)–lactose plug. The drug delivery system showed a typical pulsatile release profile with a lag time followed by a rapid release phase. The lag time was determined by the KGM/HPMC/lactose ratio, the type of HPMC, and the plug weight. The addition of β-glucanase and rat cecal contents into the release medium shortened the lag time significantly, which predicted the probable enzyme sensitivity of the KGM plug. The in vivo studies show that the plasma drug concentration can only be detected 5 h after oral administration of the capsule, which indirectly proves the colon-specific characteristics. These results indicate that the pulsatile capsule may have therapeutic potential for colon-specific drug delivery.
Four dispersions of 3% glucomannan in water, deacetylated with 5% 0.6N and 1N KOH (lots L1 and L2) and 0.6N and 1N NaOH (lots L3 and L4) as gelling agents, were evaluated for use in raw restructured seafood products. Several properties (pH, moisture content, water binding capacity, cooking loss and lightness) together with puncture data (breaking force and breaking deformation) were determined after 1 and 10 days of chilled storage at 5°C. All these data were analyzed together with different viscoelastic parameters obtained at small amplitude oscillatory strain (SAOS) after 1 day of chilled storage, showing that L1 and L4 samples were the most suitable gels for incorporation in raw restructured fish products. In both cases the highest stress (σmax) and strain (γmax) amplitude values were found in the linear viscoelastic (LVE) range; however, L1 showed both high strain amplitude and breaking deformation values. Moreover, creep and recovery (transient) data showed that L1 was the most time-stable gel with the highest elasticity and the lowest relaxation exponent (n). L4 gel showed strong rigidity, i.e. the highest values of breaking force and storage moduli (G′) and the highest n value, making it less gel-like. Both L1 and L4 gels became significantly less gel-like over 10 days of chilled storage due to the loss of gel strength (S) and a noticeable increase of n. These chilled storage effects were more intense in L4 than in L1.
The self-assembly of rod–coil carboxymethyl konjac glucomannan-graft-poly(ethylene glycol) (CKGM-g-PEG) and α-cyclodextrin (α-CD) complexes were investigated and used as encapsulating hollow nanospheres for the enzyme glucose oxidase (GOX) in aqueous solution. These hollow nanospheres exhibited “cell-like” semi-permeability allowing enzyme substrates to pass through the surface while restricting the encapsulated enzyme (i.e. GOX) to the interior. Encapsulated GOX exhibited higher thermostability, optimal enzymatic activity over a wider pH range and improved storage stability in comparison to free un-encapsulated GOX. In addition, these CKGM-g-PEG/α-CD hollow nanospheres showed in vitro biocompatibility when exposed to L929 cells when tested using MTT viability assay. These studies suggested that self-assembly of CKGM-g-PEG and α-CD to form stable nanospheres may be an effective method for enzyme encapsulation with numerous biomedical applications.
A potting experiment was carried out to determine the effects of soil amendments containing polysaccharides and earthworms
on a land application system for the purification of animal waste water. The following soil amendments were used: purified
Konjak powder (KP, powder containing glucomannan made from the root system of devil's tongue, Amorphophalus rivieri Dur.), crystallized cellulose (CC), and a mixture of the two (MX). These soil amendments were added to the pots, and then
Chrysanthemum corondria were planted in the earthworm pots (A pots), the nonearthworm pots (B pots), and the control pots (C pots); the first two
plots received primary-treated animal waste water, and the other one received tap water. The following items were then measured:
pH, electrical conductivity, chemical oxygen demand (CODMn), total nitrogen (TN), total phosphorus, the volume of drained water from each pots, the height and dry matter weight of
plants, and the water permeability into the soil. The MX-A pots, i.e., the pots containing both soil amendments and earthworms,
gave good results, especially for water permeability, plant growth, the purification of CODMn, and TN. These results suggest that the presence of soil amendments and earthworms may enhance the improvement of water quality
in land application systems using vegetation.
Various degrees of paimitoylated konjac glucomannan (PKGM) are prepared by heterogeneous method. Differential thermal analysis
(DTA) thermographs show PKGM having certain degree of substitution (DS) gave a new crystalline peak at higher temperature.
And PKGM having higher DS only shows the new crystalline state. Furthermore, the effect of the DS of PKGM on its emulsifying
ability has been investigated in the water in oil (w/o) and oil in water (o/w) systems. It is demonstrated that it is a kind
of good w/o emulsifier with the DS ranged between 1.00 and 1.70; Whereas for DS
Konjac glucomannan (KGM) exhibited liquid crystalline (LC) behaviour in aqueous solutions above 7% (w/w) concentrations as was determined by polarized optical microscopy and circular dichroism. The rheological properties of the concentrated LC solutions of KGM exhibited pseudoplastic behaviour. The fibrous extrudates retained a significant degree of flow-induced orientation as was determined by wide angle X-ray scattering, thereby indicating potential applications of KGM as fibres and films. Differential scanning calorimetry experiments showed that a significant degree of interaction occurred between KGM and water and that the KGM gels produced in our study cannot be classified as thermoreversible.
The prebiotic potential of a konjac glucomannan hydrolysate (GMH) was investigated in vitro using batch cultures inoculated with human faeces. Bacterial enumeration was carried out using the culture independent technique, fluorescent in situ hybridisation (FISH), and short chain fatty acid (SCFA) production was monitored by gas chromatography. The populations of Bifidobacterium genus, Lactobacillus–Enterococcus group and the Atopobium group all significantly increased after GMH and inulin fermentation. The Bacteroides–Prevotella group had a lower end population after GMH fermentation while inulin gave an increase, although these differences were not significant. No significant differences in SCFA concentrations were observed between inulin and GMH. As with inulin, GMH produced selective stimulation of beneficial gut microbiota and a favourable SCFA profile. In order to confirm a beneficial effect of GMH further in vivo studies involving healthy human volunteers should be considered.
Hydrocolloids are widely used in many food formulations to improve quality attributes and shelf-life. The two main uses are as thickening and gelling agents. As thickening agents, they find uses in soups, gravies, salad dressings, sauces and toppings while as gelling agents, they are extensively used in products like jam, jelly, marmalade, restructured foods and low sugar/calorie gels. The role of specific hydrocolloids for thickening and for gel formation is reviewed pinpointing specific applications in food formulations and for product development.
Konjac glucomannan hydrolysate was derived enzymatically from konjac flour under optimal conditions. A number of culture strains of lactobacilli and bifidobacteria were grown on De Man, Rogosa and Sharpe (MRS) media supplemented with the hydrolysate. This hydrolysate stimulated the growth of all strains examined. Colony sizes of those strains grown on konjac hydrolysate were significantly (P = 0.001) bigger than those grown on pectin or xylan hydrolysates. Bacterial growth profiles were also conducted on nutrient agar (MRS or modified MRS agar containing konjac hydrolysate) using single strains of lactobacilli or bifidobacteria (Lactobacillus acidophilus, Lactobacillus casei or Bifidobacterium adolescentis), single pathogen cultures (Escherichia coli or Listeria monocytogenes) or mixed bacterial cultures (from chicken breast extract). Although the growth of lactobacilli inhibited the growth of pathogens (single or mixed culture) the pathogens could not grow on the konjac hydrolysate as a sole carbon source. Microbial growth profiles using konjac hydrolysate or inulin in UHT milk were also investigated. The results showed that the numbers of colony forming units (cfu) obtained from milk containing the konjac hydrolysate were significantly (P = 0.01) higher than those containing inulin. It is suggested that the unique properties of konjac hydrolysate make it universally valuable as a prebiotic which can be applied to a wide range of foods, feeds and healthcare/pharmaceutical products. Copyright © 2007 Society of Chemical Industry
The interactions among the three phases of nano-hydroxyapatite (n-HA), Konjac glucomannan (KGM) and Chitosan (CS) in n-HA/KGM/CS
composite were investigated using TEM, IR, XRD, XPS and TGA methods. The crystalline structure of n-HA was studied by means
of Rietveld method. A series of structure parameters, such as, cell lattice parameters (a or c), bonding lengths and a numerical index of distortion for PO4 tetrahedron, were calculated by Newton–Raphson calculating method to characterize the crystalline structure of HA at atom
level. The results showed that n-HA was mainly linked with KGM and CS by hydrogen bonding between OH−–PO43− of n-HA and –C=O, –NH of KGM-CS copolymer, and there was a stable interface formed between the three phases in the composite.
Besides, orientation of this hydrogen bonding resulted in the decrease of the relative crystallization degree of KGM-CS copolymer.
The constitution of konjac glucomannan was determined by methylation analysis and 13C NMR spectroscopy. The results of methylation analysis showed that the branching point is C-6 carbon of glucosyl units. 13C NMR spectroscopy (1D and DEPT) of konjac glucomannan supported the presence of β-C-1-linked C-6 carbon of glucosyl units as the branching units. This result differs from previous investigations. The 13C NMR spectra indicated that the ratio of terminal glucosyl units to terminal mannosyl units is ca. 2 and branching frequency is ca. 8%, supporting the results by Smith et al. From the splitting of main chain signals the sequences of glucosyl and mannosyl units in konjac glucomannan are estimated and a model structure for the glucomannan is proposed.