Konjac Flour Research Articles

A pilot plant scale of Yellow Konjac (Amorphophallus muelleri Blume) flour production by a centrifugal mill using response surface methodology

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

The antifungal mechanism of konjac flying powder extract and its active compounds against wood decay fungi

Wood products are vulnerable to fungal degradation that reduces service life. Traditional wood preservatives can provide excellent service life but efforts are underway to develop more natural methods for wood protection. Konjac flying powder is a residual waste produced during the processing of corms of Konjac (Amorphophallus konjac K. Koch) to produce Konjac flour. This waste material contains a number of compounds including salicylic acid (SA), 2,4,6-trichlorophenol (TCP), vanillin (VL), and cinnamaldehyde (CMA) has been found to be active against decay fungi; however, the antifungal mode of action is uncertain. The effects of konjac flying powder extract (KFPE) and its active compounds on cellulase, hemicellulose and ligninase activity, respiratory metabolism, cell membrane permeability, protein, and energy metabolism was studied on the white-rot fungus, Trametes versicolor (L. ex Fr.) Quél. (T. versicolor) and brown-rot fungus, Gloeophyllum trabeum (Pers.: Fr.) Murr. (G. trabeum). Konjac flying powder inhibited cellulase and hemicellulase activity of both fungi and ligninase activity of T. versicolor. Respiratory metabolism and energy metabolism were also inhibited. The four active compounds had different effects on activities suggesting that konjac flying powder functioned against multiple metabolic activities of the test fungi, potentially increasing its ability to provide broad spectrum wood protection.

Effect of whey protein on the 3D printing performance of konjac hybrid gel

3D printing technology is a rapid prototyping technology. It has been widely applied in food field now. Konjac flour comes from konjac tubers, and whey protein comes from milk. The gel system formed by them can be used in the 3D printing process. This study investigated the 3D printing performance and supportability of the konjac-whey protein gel system. The results show that the rheological properties of the konjac gel added with whey protein have been improved, including storage modulus (G’) and viscosity, etc. Textural properties of gels like hardness, springiness, chewiness, gumminess, and cohesiveness have been also enhanced. Microstructure analysis shows that the addition of whey protein will change the original gel structure and it will form a new structure with a denser gel. It will also affect the supporting performance of printed products and the fluency of extrusion process. According to the results, we can conclude that the addition of whey protein powder has an effect on 3D printing performance of the gel. Addition of 20% whey protein can significantly improve the printing performance.

Research Article Product Composition Analysis and Process Research of Oligosaccharides Produced from Enzymatic Hydrolysis of High-Concentration Konjac Flour.

There is a huge variability in reducing sugars, viscosity, and composition of oligosaccharides in the hydrolyzed products of konjac flour with different concentrations. We analyzed the factors affecting reducing sugars, viscosity, and the average degree of polymerization (DP) during the preparation of oligosaccharides from konjac flour hydrolyzed by β-mannanase under the high-concentration solute hydrolysis model. Hydrolysate of konjac flour, using concentrations ranging from 50 to 200 g/L, was directly added into 20 U/mL of β-mannanase solution. The results showed that when the proportion of the water content in the solution decreased, the viscosity of the solution and the DP of polysaccharides changed significantly. When the viscosity of the hydrolysate was controlled within the range of 30–20 mPa·s, the concentration of the reducing sugars was maintained in the range of 9–13 g/L and the average DP of the polysaccharides was controlled in the range of 2.42–9.78. We also found that a high concentration of hydrolysate was beneficial for decreasing the production of reducing sugars, and the diversification of macromolecular glycan was beneficial to the preparation of functional sugars. Moreover, we observed that the proportion of reducing sugars with free water content was high and that the preparation of oligosaccharides via the high-concentration solid-state method increased product diversity.

Formulation and characterization of body scrub using marine alga Halimeda macroloba, chitosan and konjac flour

Body scrub is a cosmetic product that contains slightly rough material that can remove dead skin cells. Natural ingredients such as Halimeda macroloba is potential to be used as scrub. H. macroloba deposits CaCO3 in the thallus which makes the texture of Halimeda flour is rougher than that of other flour so that it is potentially used as a scrub. The emulsion-forming agent for body scrub can use konjac flour. Konjac flour contains high glucomannan which can used as emulsifier. This study aimed to determine the characteristics of body scrub using H. macroloba and konjac flour. Formulation of body scrub in this study was carried out by mixing water base (propylene glycol, glycerine, aquadest) and oil base (cetyl alcohol, stearic acid, DEA, perfume) at temperatures of 70 °C and 80 °C. Afterwards the mixture was added with 3% of H. macroloba and 2% of konjac flour. Body scrub produced in this study contained moisture of 58.49-75.15%, viscosity 10 106.67-14 900.00 cP, pH 6.48-6.93, whiteness 67.74%-95.96%, and spread ability 1.63-2.17 cm. The highest macro mineral content was calcium (Ca) with an average of 8.24 mg g-1, while the highest micromineral was iron (Fe) with an average of 16.85 ppm. The most preferred formula for colour and aroma based on the result of hedonically assessment was formula 2 (fresh H. macroloba with chitosan 2%), while the most preferred for thickness and texture was formula 5 (dried H. macroloba with chitosan 2%).

PSVIII-7 In vitro fermentation of different dietary fibers selectively changed sow gut microbiota composition

Abstract In vitro fermentation experiments with modified starch 1 (MS1), modified starch 2 (MS2), guar gum (GG), xanthan gum (XG), konjac flour (KF), wheat brain (WB), and inulin (I) were conducted for 48 h to investigate the effects on gilt gut microbiota. Fecal examples were obtained from three gilts; the fermentation kinetics parameters were analysed in Logistic-Exponential (LE) model such as the final asymptotic gas volume (Vf, ml/g), initial fractional rate of degradation at t-value=0 (FDR0, h-1), fractional rate of gas production at particular time (k, h-1) and half-time to asymptote (T1/2, h). Samples were collected after fermentation for short chain fatty acids (SCFAs) and 16S rDNA microbial analysis. MS1, MS2, and I had the highest Vf (P < 0.01). The k of GG and I were significant higher (P < 0.01). FDR0 of MS2, GG, and I were the lowest following KF, MS1, WB, and XG, successively (P < 0.01). T1/2 of MS1, KF, WB, and GG were lower (P < 0.01). MS1, MS2, and GG produced more acetate (P < 0.05) and total SCFAs (P < 0.01), and butyrate produced by MS2 was significant higher (P < 0.01). The microbiota composition changed dramatically after fermentation, decreasing bacteria abundance and alpha-diversity (P < 0.01). The relative abundance of phyla Firmicutes and Bacteroidetes decreased, while phyla Spirochaetes, Proteobacteria, Kiritimatiellaeota, and Fusobacteria were selectively promoted by DF. The LEfSe analysis showed Proteobacteria, Gammaproteobacteria, and Aeromonadales were enriched in MS1 treatment; Clostridiales, Clostridia, and Anaerosporobacter were enriched in MS2 treatment; Bacteroidales, Bacteroidia, and Bacteroidetes were enriched in GG treatment; Ruminococcaceae and Ruminococcaceae_UCG_013 were enriched in XG treatment; Lachnospiraceae, Lachnospiraceae_NK4A136_group, and Ruminiclostridium were enriched in KF treatment; Enterobacteriales, Enterobacteriaceae, and Lactobacillales, were enriched in I treatment. In conclusion, different type of DFs may play a specific role in gilt gut microbiota changing and composition.

Chemical and physical characterization of Konjac glucomannan-based powders by FTIR and 13C MAS NMR

Konjac glucomannan (KGM) is extracted from Amorphophallus konjac tuber and composed of β-1,4 linked D-mannose and D-glucose. We aimed to produce and characterize KGM-based powders manufactured from dried (55°C-KF55 and 75°C-KF75) konjac tubers and compare to a commercial konjac glucomannan (CKG) powder. Structural characteristics on molecular, compositional, and microstructure levels as well as rehydration properties were assessed. Both compositional analysis as well as FTIR and 13C MAS NMR spectral analysis demonstrated a higher amount of protein than KF55 sample. The ratio between the two monomer units (D-mannose and D-glucose) was 1.6:1 in KF75, whereas it was 1.4:1 and 1.2:1 for KF55 and CKG, respectively, indicating slightly higher Man:Glc ratios in the KF samples. Decreased rehydration properties and flow index behavior (in solution) were observed in the konjac flours. Thus, differences were significant; konjac flours also presented good functionality, thereby, a good alternative to be used as hydrocolloid in food formulations.

Identification of antifungal compounds in konjac flying powder and assessment against wood decay fungi

Public concern for the environment has stimulated the development of natural wood preservatives. The antifungal activity of konjac (Amorphophallus konjac K. Koch) flying powder (a by-product produced during mechanical processing of konjac flour) ethanol extracts was evaluated against wood decay fungi in poplar (Populus nigra L.). Compounds associated with antifungal activity in the extracts were isolated and purified by silica gel column chromatography. The antifungal active fractions were identified by ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS). The ethanol extracts showed better activity against the brown-rot fungus, Gloeophyllum trabeum (Pers.: Fr.) Murr. than the white-rot fungus, Trametes versicolor (L. ex Fr.) Quél. in poplar. The antifungal active fractions were mainly composed of organic acids and plant essential oils. Salicylic acid, 2,4,6-trichlorophenol, vanillin and cinnamaldehyde were present in the active fractions. These compounds showed high efficacy against both fungi in poplar. The results indicate that konjac extracts have potential as natural wood protectants and suggested that some fractions of konjak flying powder may be useful for protecting wood against fungal attack.

Impacts of Hydrocolloids on Physical, Microbiological and Sensorial Qualities of Swai-Fish-Based Emulsions Subjected to High Pressure Processing

ABSTRACTThe objective of this study was to examine how konjac flour or carboxymethylcellulose (CMC) could improve the physical, microbiological, and sensorial qualities of pressurized Swai fish-based emulsions. The properties of the pressurized batches were also compared with those of the heated emulsions. Accordingly, Swai fish-based emulsions containing mixed fermented-soybeans were stabilized by either konjac flour or CMC, 0.1–0.3%. The fish batters were then subjected to pressurization (600 MPa/25°C/20 min) or thermal treatment (72°C/30 min). The results showed that both hydrocolloids enabled improvement of the color of fish emulsions. Regarding the impact of hydrocolloids on other properties, CMC addition enhanced water holding capacity, gel strength, and elasticity more than konjac flour addition. Regarding processing effects, pressurization gave rise to products with greater water holding capacity and higher sensorial scores than the thermal treatments. However, thermal treatments increased the gel strength and elasticity of the products more than pressurization. Overall, both processes could equally inhibit bacterial cells and some spores of B. subtilis.

Manno‐oligosaccharide preparation by the hydrolysis of konjac flour with a thermostable endo‐mannanase from Talaromyces cellulolyticus

A thermostable endo-mannanase from the fungus Talaromyces cellulolyticus was identified to facilitate manno-oligosaccharide preparation from Konjac (Amorphophallus konjac) flour. A putative endo-1,4-β-mannanase from the T. cellulolyticus was obtained and efficiently expressed by improving its gene dosage in the genome of the host. After cultivation in a bench-top bioreactor for about 120h, the protein content and enzyme activity of mannanase increased to 3·4gl-1 and 17500Uml-1 respectively. Enzymatic characterization showed that this enzyme has an optimal temperature of 80°C, optimal pH of 5·0. Under the optimized hydrolysis conditions of pH 5·0, 70°C, and an enzyme concentration of 200Ul-1 solution, this enzyme could efficiently hydrolyse 0·5% konjac flour into manno-oligosaccharides (MOSs) with the degree of polymerization range from 3 to 7. The possible mechanism by which the enzyme produced MOSs was also discussed. Talaromyces cellulolyticus endo-mannanase is thermostable and has a broad pH range adaptability. Method of improving the dosage of mannanase gene in the genome could realized its high-level impression. This enzyme could efficiently hydrolyse konjac flour into manno-oligosaccharide products. This study has enriched endo-mannanase resources, facilitated its bulk production and provided a strong reference for its application in manno-oligosaccharide preparation from the natural glucomannan of konjac flour.

Effect of dietary fiber-rich fractions on texture, thermal, water distribution, and gluten properties of frozen dough during storage

The effect of dietary fiber-rich fractions on the texture, thermal, water distribution, and gluten properties of frozen dough during storage was investigated. These fractions could greatly improve retention of the texture properties, which was mainly related to water loss, and changes in freezable water proportion (FW) and gluten secondary structure. Kinetic studies showed that the fractions could change the nucleation type and ice crystal growth rate, with konjac flour significantly decreasing the ice growth rate from 0.0177 to 0.0048. These fractions could decrease FW by 15%–27% and restrict water mobility during storage. Moreover, gluten β-sheets shifted toward β-turns, while the β-sheet values of potato and okara flours showed no significant change during storage. SEM confirmed that okara flour could suppress the deterioration of gluten. Generally, the potato, okara, and konjac flours represent excellent fortification materials that could improve the texture, reduce water mobility, and suppress deterioration of frozen dough during storage.

Local tubers and beans processing innovation for micro enterprises diversification

Local commodities such as tubers and beans are abundant throughout Indonesia, but its economic value is low and still only a minor source of income for the rural areas community. The purpose of this study was to improve technological access of inferior local tubers and beans processing thus increasing the added value and facilitates the community economic revenues. The first step of this study was conducted to identify the nutrients content of local commodities correspond to the requirements of food bars production. The second stage done to seek the composition of each component i.e. sweet potato flour, cowpea flour, and mung beans flour and also konjac flour addition to reach a good food bars characteristics. The product was then evaluated in terms of product appearance, nutritional value, and acceptance by consumers. The outcome of this study was to utilize local commodities convert to product that can be adopted by the rural community. The result show that the composition of sweet potato flour, cowpea flour, and mung bean flour of 50: 20: 30 with the addition of 25 grams konjac flour was the best composition. Glucomannan of konjac flour affects to the quality of food bars especially to its strength.

Influence of the Addition of Potato, Okara, and Konjac Flours on Antioxidant Activity, Digestibility, and Quality of Dumpling Wrappers

To improve the antioxidant activity (AA), digestibility, and quality of fiber-rich dumpling wrappers, potato, okara, and konjac flours were added to wheat flour. The contents of these additional ingredients in the dumpling wrapper were optimized using the response surface methodology and the synthetic evaluation method. The dietary fiber content (DFC) and AA of blend flours and the optimized cooking time (OCT), cooking loss (CL), hardness, chewiness, firmness, color, and sensory evaluation (SE) of dumpling wrappers were evaluated as response quality parameters. The optimized flour was identified containing 17.5 g of potato flour, 8.5 g of okara flour, and 1.2 g of konjac flour per 100 g of blend flour, which resulted in a higher synthetic evaluation index value (0.71 compared with 0.68 for wheat flour). The qualities of the optimized flour dumpling wrappers were compared with those of wheat flour dumpling wrappers to verify the practicality of the optimized flour. The results showed that the optimized flour showed better comprehensive qualities, especially regarding DFC (9.59%, fourfold higher than that of wheat flour) and AA. Furthermore, the predicted glycemic index (GI) of the optimized flour (74.93%) was lower than that of the wheat flour (81.47%). Overall, the addition of potato, okara, and konjac flours can significantly (P<0.05) improve DFC, AA, and digestibility of wheat flour. The optimized flour not only maintains excellent dumpling wrapper quality but also increases the utilization of potato and okara flours, which has great potential for industrial applications.

Konjaku flour reduces obesity in mice by modulating the composition of the gut microbiota.

Changes in the intestinal flora composition is referred to as dysbiosis, which is related to obesity development, thus supporting the potential roles of nutrients acting on intestinal flora to exert salutary effects on energetic metabolism of host. Dietary fiber has been known to affect the composition of intestinal flora. The aim of the present study was to investigate the functional effects of konjac flour (KF) on obesity control in respect to improving inflammation, metabolism, and intestinal barrier function, and the possible association of the effects with intestinal flora composition changes. Mice (n = 30) were randomly divided into control group (n = 10), high-fat-diet (HFD) group (n = 10), and KF intervention group (n = 10), followed by feeding for 12 weeks and with adding a KF daily supplementation for the treatment group. Body weight, fat accumulation, inflammation, and energetic metabolism markers in multiple tissues and the gut microbiota of the mice were examined at the end of the experiment. The KF supplementation significantly reduced the gains in weight, fat mass, as well as adipocyte size of HFD mice and lowered the serum TC, leptin (LEP), thiobarbituric acid-reacting substance (TBARS), IL-6, and lipopolysaccharide (LPS) levels in HFD mice. KF also upregulated the expression of intestinal mucosa protein gene Intection and tight junction ZO-1 in HFD mice, as well as upregulate the expression of energy metabolism genes PPARα and CPT-1 as well as the fat metabolism gene HLS in livers and fat tissues, and downregulate that of fat synthesis gene PPARγ (p < 0.05). The KF treatment increases the α-diversity and change the β-diversity of the intestinal microflora in HFD mice and boosted the abundances of some obesity-related beneficial microorganisms (such as Megasphaera elsdenii) in the intestinal microflora of HFD mice, while reduced those of harmful microorganisms (such as Alistipes, Alloprevotella, Bacteroides acidifaciens, and Parabacteroides goldsteinii). The abundance of Alistipes was positively correlated with weight, fat mass, serum TC, TG, LEP, IL-6, and LPS contents as well as PPARγ gene expression; while notably and negatively related to the expression of CPT-1 and HLS genes (p < 0.01). KF remarkably increased the abundance of Aerococcaceae, while reduced that of Alistipes finegoldii (p < 0.01). Supplementation with KF achieves favorable effects on treating obesity, improving inflammatory response, metabolism, and intestinal barrier function, by regulating intestinal microfloral structure in HFD-fed mice.

Preparation and Characterization of Lactobacilli-Loaded Composite Films with Sustaining Antipathogenic Activity and Preservation Effect.

For the sake of the high desires of consumers for food safety and quality, the development of innovative bioactive packaging has attracted wide attention. In this work, the prepared films containing lactic acid bacteria showed great physical property, antipathogenic activity, and fresh-keeping property preservation, and have great application potential in fresh food preservation.

Effect of combination of three texture-improving ingredients on textural properties of emulsified sausage-containing salted egg white.

Response surface methodology based on Box–Behnken was used to assess the effects of three kinds of texture‐improving ingredients, namely, mixed starch (MS) (6%–8%) of sweet potato starch and glutinous rice flour, k‐carrageenan (CG) (0.4%–0.6%), and konjac flour (KF) (0.8%–1.2%), on the firmness, elasticity, and water holding capacity (WHC) of emulsified sausage (ES) made from pork and salted egg white (SEW). The three kinds of texture‐improving ingredients individually presented different effects on firmness, elasticity, and WHC. Their synergistic effects were significant. The three response models obtained by ANOVA were suitable to predict firmness, elasticity, and WHC. These models can also be used to design formulations for different types of sausage with different firmness and elasticity. The combination of MS (7.36%), CG (0.60%), and KF (1.20%) can produce SEW‐containing ES with remarkable firmness (224.04 g), elasticity (8.62), and WHC (8.41).

Digestible energy and metabolizable energy contents of konjac flour residues and ramie in growing pigs.

The objectives of this study were to determine: 1) the effects of konjac flour residues and ramie on digestible energy (DE), metabolizable energy (ME) and apparent total tract digestibility (ATTD) of nutrients in diets fed to growing pigs, 2) the DE and ME contents of konjac flour residues and ramie. Thirty barrows were allotted to 1 of 5 treatments with 6 replicates per treatment. The 5 diets include a corn-soybean meal basal diet (CTL), konjac flour residues diets containing 15% konjac flour residues (LK) or 30% konjac flour residues (HK), and ramie diets containing 15% ramie (LR) or 30% ramie (HR). The experiment lasted 19 days, including 7 days for cage adaptation, 7 days for diet adaptation, and 5 days for total feces and urine collection. The energy values and ATTD of nutrients in each diet were determined, and DE and ME contents of konjac flour residues and ramie were calculated. The results showed that consumption of konjac flour residues significantly increased (P < 0.01) the fecal moisture content compared with the ramie treatment. The LK, HK and HR diets had lower (P < 0.01) DE values compared with the CTL diet. The HR diet had greater (P < 0.01) DE value compared with the HK diet. The LK and LR diets showed greater (P < 0.01) ATTD of DM, OM, GE and CP compared with the HK and HR diets. The HK diet had the lowest (P < 0.01) ATTD of ether extract (EE) among the 5 diets. No differences were observed for the ATTD of NDF and ADF among the 5 diets. Moreover, the DE and ME values of konjac flour residues under 2 inclusion levels (15% and 30%) were 11.66, 11.87 MJ/kg and 10.41, 10.03 MJ/kg, respectively. The corresponding values for ramie were 13.27, 13.16 MJ/kg and 13.07, 12.82 MJ/kg, respectively. In conclusion, the differences in fecal moisture content and the ATTD of EE among the 5 diets were mainly due to the different chemical compositions of konjac flour residues and ramie. Compared with konjac flour residues, ramie has greater DE and ME values under the same inclusion level.

Effects of soluble fiber inclusion in gestation diets with varying fermentation characteristics on lactational feed intake of sows over two successive parities

The effects of soluble fiber inclusion in gestation diets with varying fermentation characteristics (fermentation kinetics and short-chain fatty acids (SCFA)-profile) on lactational feed intake of sows and their piglet growth over two parities were investigated using an in vitro–in vivo methodology. After breeding, 90 multiparous Landrace sows were randomized to one of three experimental diets: the control (CON) diet, konjac flour (KF) diet or sugar beet pulp (SBP) diet. All diets had similar levels of net energy, CP, insoluble fiber and NDF, but KF and SBP diets had higher soluble fiber levels than the CON diet. During gestation, the sows were restrictively fed with three different diets, but during lactation, all the sows were similarly fed ad libitum. The three gestation diets were enzymatically hydrolyzed using pepsin and pancreatin, and enzymolyzed residues were used in in vitro fermentation. Gas and SCFA production were monitored during fermentation. After fermentation, enzymolyzed residues of KF or SBP diets resulted in higher final asymptotic gas volume than those of the CON diet. The enzymolyzed residues of KF diet were mainly part of rapidly fermented fractions, whereas those of SBP diet were mainly part of slowly fermented fractions. In addition, the acetic acid, butyric acid and total SCFA concentrations of enzymolyzed residues of KF diet were higher (P<0.01) than the control and SBP diets. In the in vivo studies, on day 90 of gestation, the KF diet sows had higher plasma SCFA concentration (P<0.05) at 4 h after feeding than the CON diet sows. Furthermore, the KF diet sows had lower plasma free fatty acid (FFA) concentration (P<0.01) at 4 h after feeding, and a lower value of homeostasis model assessment (HOMA)-insulin resistance (P<0.05), but a higher value of HOMA-insulin sensitivity (P<0.01). The KF diet sows also consumed more feed during lactation (P<0.01) and weaned significantly heavier pigs (P<0.01) than the CON diet sows. The overall results showed that the high fermentation capacity KF diet contributed to an increased lactational feed intake and improved performance of piglets in the second reproductive cycle.

Effect of meat enhancement solutions with hydroxypropyl methylcellulose and konjac flour on texture and quality attributes of pale, soft, and exudative pork.

Meat processors could use KHCO with HPMC or KF as ingredients to improve color, texture, and pH of PSE meat. The reduction of variation between PSE and normal pork muscle would improve pork quality and add value to PSE meat products.

Biochemical characterization of thermostable β-1,4-mannanase belonging to the glycoside hydrolase family 134 from Aspergillus oryzae.

A β-1,4-mannanase, termed AoMan134A, that belongs to the GH 134 family was identified in the filamentous fungus Aspergillus oryzae. Recombinant AoMan134A was expressed in Pichia pastoris, and the purified enzyme produced mannobiose, mannotriose, mannotetraose, and mannopentaose from galactose-free β-mannan, with mannotriose being the predominant reaction product. The catalytic efficiency (k cat/K m ) of AoMan134A was 6.8-fold higher toward galactomannan from locust bean gum, than toward galactomannan from guar gum, but similar toward galactomannan from locust bean gum and glucomannan from konjac flour. After incubation at 70°C for 120min, the activity of AoMan134A toward glucomannan decreased to 50% of the maximal activity at 30°C. AoMan134A retained 50% of its β-1,4-mannanase activity after heating at 90°C for 30min, indicating that AoMan134A is thermostable. Furthermore, AoMan134A was stable within a neutral-to-alkaline pH range, as well as exhibiting stability in the presence of a range of organic solvents, detergents, and metal ions. These findings suggest that AoMan134A could be useful in a diverse range of industries where conversion of β-mannans is of prime importance.