Araceae Amorphophallus konjac, perennial herb, alkaline plant. There are a lot of konjac tuber glucomannan (KGM), is a polysaccharide by D- glucose and D- mannan according to the molar ratio of 1:1.6 to -1,4 beta sugar Gan bonds, its content is about 44% ~ 64%, polysaccharide chain complex structure determines its unique excellent properties, can be used as gelling agent, thickener agent, stabilizer, emulsifier and additives, widely used in the field of food and environmental protection etc.. Glucomannan is a colorless, odorless and difficult to be digested and absorbed by the human body of a high hydrophilic polymer compounds, with edible, health care, purification of water quality and other effects. With the continuous development of technology and the use of demand, through processing, modification, composite and other ways, so that it has new features and applications, broaden the scope of use and application areas.
Gelation of konjac glucomannan: konjac glucomannan soluble in water, in alkaline conditions and is soluble in water, gel forming solution, because the water molecules in the diffusion migration, konjac particles will swell, the particles in surface layer of thin film viscous liquid, mutual adhesion between particles. In order to play the role of water flowing through the absorption and purification.
The thickening property of konjac glucomannan is due to its high molecular weight, strong hydrophilic ability and no charge, and produces viscous liquid in the process of dissolving water, which makes it have good thickening property.
The stability of konjac glucomannan: stability of konjac glucomannan by temperature, PH, purity and other factors, and decreased with increasing temperature, the change of PH made of konjac glucomannan viscosity decreases, the optimum PH is 3 to 9, the purity is higher, more stable.
The rheological property of konjac glucomannan is that konjac glucomannan is insoluble in organic solvent, and its aqueous solution is pseudoplastic fluid, which has shear thinning property. Its apparent viscosity is inversely proportional to shear rate, and decreases with increasing temperature, and irreversible.
Film properties of konjac glucomannan konjac glucomannan dissolved in water will produce a layer of chitosan dope, can be made into epidural after dehydration of high density and transparency, is not affected by the temperature and acidity, through the use of additives to change its permeability and softness.
Application of konjac glucomannan in food field
Konjac glucomannan is widely used in many aspects of food industry according to its excellent properties and various functions.
1 Food additives
In daily life, the ingredients such as ham and tofu can be increased by adding proper amount of konjac flour, which can also improve the quality of products, increase the beneficial dietary fiber, and make up the plant protein. In recent years in food cooking meat food phenomenon, is to use the same characteristics of konjac irreversible gelation, the plasticity, toughness, smoothness, and other accessories, elaborate, can produce a variety of vegetarian meat products, is the bionic vegetarian products.
In addition, konjac flour can also be used together with xanthan gum, carrageenan, etc., to play a role in increasing the effect. The production process of ice cream, add more than three kinds of edible glue and other materials can be made into ice cream emulsion stabilizer, the ice cream form stable, taste better, not easy to appear the phenomenon of ice crystals, but also can make the production of more simplified, improve production efficiency and prolong the shelf-life time.
2 Food antistaling agent
Traditional fruit and vegetable preservation method is to apply chemical agents such as two butyl hydroxy toluene (BHT) and benzoic acid on the surface of fruits and vegetables. These chemicals can easily lead to harmful effects of toxin accumulation and carcinogenesis in the users, and the cost is relatively low, which is more toxic. By using the gel property of Konjac Glucomannan and the treatment of alkaline alcohol, a new preservative is prepared, which is not only of low toxicity, low cost, good effect, good fresh-keeping effect, easy to eat, and improve the preservation time of fruits and vegetables.
3 Substitute material
Konjac glucomannan contains food fiber and a variety of amino acids and other human elements, can provide a variety of daily food needs for the human body, is an ideal alternative to staple food materials.
Making full use of the thickening and stability of konjac juice can be used to replace agar and pectin of high cost materials, prevent excessive precipitation and affect the taste of drinking, and reduce the cost. Edible packaging paper, jelly and formulated yogurt, etc., in the production process, the use of konjac characteristics, replacement of high cost materials, to reduce costs and improve production efficiency.
Application of konjac glucomannan in environmental protection field
Konjac glucomannan is widely used in the field of environmental protection, including agriculture, construction and other industries.
1 Environmental protection of konjac glucomannan in agriculture
The current agricultural film is mainly composed of polyethylene and polyvinyl chloride production, although it has been widely used, and the result is good, but there are also disturbing shortcomings, this is because these materials are made of plastic to plastic products, not easy to be abandoned after natural degradation, likely to cause environmental pollution problems. Does not comply with the policy of sustainable development in china. Konjac glucomannan has good film-forming property and stability, the use of alternative polyethylene and polyvinyl chloride film production is feasible, but because of konjac glucomannan has strong hydrophilicity, while the swelling will affect the film formation and stability, caused the decrease in hardness, is not stable enough, therefore, in order to solve this the problem, adopted chemical method, the konjac powder and starch, modified, made of biodegradable material, plastic film is not easy to solve the shortcomings of natural degradation, while maintaining its advantages, made an important contribution to the agricultural production and environmental protection.
Modern chemical fertilizers and pesticides are mostly small molecular compounds, which are difficult to dissolve in water. They are easy to be transferred and lost after rain or water erosion, which not only reduces the efficiency, but also causes serious pollution to the environment, such as water eutrophication or toxic water quality. Make full use of Konjac Glucomannan and hydrophilic thickening, adding konjac flour in the production process of chemical fertilizer, chemical fertilizer in the rain is not to make the new transfer into the soil water erosion, but, not easy to lose, and the water swelling effect, increase the viscosity and the adhesion was fully absorbed in around the plant, improve the utility of fertilizer. The spraying of pesticide uses the film-forming property of konjac glucomannan, which makes it easy to form film, cover the surface of plant, enhance the drug resistance, and resist insect pest.
2 Environmental protection of konjac glucomannan in construction industry
The main application of konjac glucomannan in building industry is substitute material and dustproof agent. Modern furniture materials painted surface adhesion part contains a large number of formaldehyde, excessive inhalation of formaldehyde is likely to endanger human health. Konjac glucomannan has strong hydrophilicity, thickening and stability. The use of these characteristics, making low cost, non-toxic, strong stability of adhesives to replace toxic components, greatly reducing the environmental pollution and harm to human body.
In the process of building construction, it is easy to produce a large number of dust pollution environment. Using konjac glucomannan has hydrophilic and gelling properties, through mixing with other reagents to prepare dust agent sprayed around the site, the dust can be absorbed during construction, to achieve dust control effect.
3 Environmental protection of konjac glucomannan in other industries
In the process of wastewater purification, polyaluminium chloride and polyaluminum chloride are usually used as flocculants, but the use of these two materials is easy to cause the two pollution of aluminum. Konjac glucomannan has strong hydrophilic and gelling properties. It is used as a new type of environmental friendly flocculant by blending with protein, and is applied to the treatment of wastewater. The flocculant can be combined into cohesive particles in water and form a adsorption net, which has the advantages of large volume, good adsorption effect, low cost, no two pollution, and conforms to the standards of water purification and protection.
Development prospect of konjac glucomannan
Konjac glucomannan is a kind of natural dietary fiber, which has many excellent characteristics, and is widely used in many fields, such as food and environmental protection, and has good practicability. Through the use of the reaction situation, the use of various aspects of the effect significantly increased, therefore, whether it can be widely used, better performance has become its main research direction. Through a thorough study on its structure and properties, to further understand the interaction of glucomannan molecular conformation and intermolecular, and its modification and blending with each other, and the corresponding experiments, observe the changes in the reaction process and reaction product properties, further research possibility of derivative product characteristics and related application.
Konjac glucomannan by modification can be used in the process of wastewater purification as flocculant, its main function is the removal of suspended particles, good flocculation effect, but whether the flocculant can be reused and recycled, it can completely replace the polymerization aluminum chloride and poly aluminum chloride is widely used in sewage treatment plant and tap water factory, is a question worth considering and the future direction of development. Modified konjac glucomannan can also be used as a new nano material, applied in chemical industry, building, materials and other aspects, is an important direction worthy of further research and development, and laid a foundation for the development of high-tech in the future.
