Konjac Powder
Chemical Composition
konjac contains 50%-60% glucomannan, 20-30% starch, 2-5% fiber, 5-10% crude protein, 3-5% soluble sugars (monosaccharide and oligosaccharide) and 3-5% ash (minerals).
Chemical Structure of Konjac Glucomannan (KGM)
molecular polysaccharide, is formed when the residues of glucose and mannose are polymerized at the ratio of 1:1.6 by beta -1.4 indican linkage. On C-3 of some glucose residues are side chains composed of Beta--1.3 indican linkage. On the main chain, 1side chain occurs per 3280 glucose residues, and on each side chain there are several or dozens of glucose residues. On average, there is 1 acetyl bonded by ester linkage on the side chain per about 19 glucose residues. The molecular weight of KGM varied from 1,000,000 to 2,000,000 daltons according to konjac species or variety, processing method and storage time of the raw material.
Nutrition & Health Caring Functions of KGM
Konjac is generally grown in mountainous areas of relatively high altitudes, far from the air and water pollution in the urban areas. In addition, little pesticide and chemical fertilizer is used in its cultivation. Therefore the raw material is free from pollution. The major component of konjac is high quality soluble dietary fiber, which has the function of regulating the nutrient unbalance. Its primary physiological functions are:
1 Remarkably reduce the content of blood sugar and cholesterol and regulate lipid metabolism
Taking proper amount of glucomannan can help reduce the content of blood sugar and cholesterol remarkably. Scientific research shows that the capability of different hydrophilic gums to reduce blood sugar is in direct ratio with the viscosity of the hydrophilic gums. The function mechanism for konjac powder to reduce blood sugar attributes to its capability to reduce the absorption of sugar in the tract. According to pharmacological researches, glucomannan can increase the viscosity of gastric stuff and meanwhile produce a barrier around the food to retard the absorption. Konjac powder has achieved very good results in clinical experiments for treating diabetes.
The function mechanism for konjac powder to reduce the content of cholesterol in the blood is generally related to absorbing and combining with the cholesterol in the intestines and increasing the excretion of cholic acid. Konjac powder prevents intestine walls from absorbing cholesterol, cholic acid, heavy metal and edible pigments through its own absorption of the above matters, helping removing these materials from the body and thus significantly lowering the level of cholesterol and triglyceride in the blood.
These researches prove that konjac powder can be used as an effective food accessory or dietary additive to reduce cholesterol content.
2 Prevention & Treatment of Constipation and Obesity
As a natural hydrophilic gum of high water-absorbency, konjac powder swells in volume after absorbing water in the large intestine so as to increase the volume and looseness of dejecta, which is good for defecation. Short-bond fatty acid decomposed from konjac powder through colon bacteria cluster can promote the movement of intestines to shorten the defecation and prevent diarrhea.
Due to its high swelling coefficient after absorbing water, konjac powder can help filling up the stomach and increasing the feeling of fullness. Meanwhile, it can prevent the absorption of nutrient elements that produce heat, thus to achieve the goals of preventing obesity and controlling the weight. Taking orally certain amount of konjac powder each day can result in the obvious effect of weight control.
The Physicochemical Properties of Konjac Glucomannan
KGM has the physicochemical properties of water solubility, thickening, stabilizing, jelling, suspending, film-forming, etc.
1 Water solubility: KGM can be readily dissolved in cold or hot water and can absorb water as much as 100-200 fold in volume. Its water solution is a pseudo-plastic liquid, characterized by shear thinning, i.e. the apparent viscosity is lowered with the increase of shear rate. Therefore, test of viscosity should be carried out under strictly controlled conditions.
2Thickening: Owing to its properties of great molecular weight, high hydration capacity and freedom of electric charges, etc., KGM is a good thickening agent. The viscosity of 1% KGM solution is as high as 5000-40000 mpa, the highest among all natural thickening agents and much higher than that of guar gum and fruit gum, which means that, in practical applications, konjac gum of very low concentration can achieve satisfactory thickening and structure-improving results. Konjac gum has the capacity of maintaining the stability and structural moistening of goods after heating, while other thickening agents fall short of such capability.
3Stabilizing: In comparison with other thickening agents such as xanthan gum, guar gum, locust bean gum, etc., konjac gum is of non-ionic type and is therefore little influenced by the salt in the system. At ambient temperature, konjac gum remains stable even if the pH value drops to a level below 3.5. When konjac gum is used instead of locust bean gum as the stabilizing agent and is added to ice cream, cheese and other diary products, it will stabilizing their quality by preventing the development of ice crystals.
4Jelling: KGM has the unique jelling ability. By putting a little alkali into 2%-3% konjac solution, heating to 85Deg.C and leaving it alone for two hours, an elastic, solid and irreversible gel will be formed. This kind of gel has unmatched high thermo-stability and is hard to melt even under prolonged heating. Other hydrophilic gums such as guar gum and carrageenan cannot form such gel. The test of forming thermo-stable gel can differentiate konjac gum from guar gum, carrageenan and other hydrophilic gums. By utilizing its thermo-irreversible property of konjac gum, it may be used to make a variety of foods, such as konjac cake, konjac noodle, animal food-imitating food, vegetarian food, etc.
5Synergistic Effect with Other Hydrophilic Gums
Konjac gum and xanthan gum do not gelatinize when used alone but can form gel when used in combination under certain conditions and can result in the strongest synergistic effect at pH 5. When konjac gum and xanthan gum is formulated at the ratio of 3:2, the intensity of the produced gel is the highest. The gel produced by combining konjac gum and xanthan gum is reversible and can turn into sol when heated, which can be restored to gel at the indoor temperature.
The combination of konjac and carrageenan can also result in obvious synergistic effect. When konjac and carrageenan are formulated at a ratio of 1:4, the intensity of the produced gel reaches the highest; when formulated at a ratio of 4:1, the gel reaches the maximum viscosity. The carrageenan colloid added with konjac gum features excellent elasticity and tenacity.
Besides, konjac and guar gum can also produce obvious synergistic effect if used together.
Specification:
Konjac gum
1.Normal Powder
Grade 1
Appearance: white powder
Particle sizes:120-200mesh
KGM:85%Min
Viscosity:18000Mpas
Ash:2.8%Max
SO2:0.6g/kg Max
As:0.5PPM Max
Pb:1.0PPM Max
Moisture:11%Max
PH:6-8
Smell:Odorless
2.Grade 2
Appearance: white powder
Particle sizes:120-200mesh
KGM:88%Min
Viscosity:22000Mpas
Ash:2.2%Max
SO2:0.5g/kg Max
As:0.5PPM Max
Pb:1.0PPM Max
Moisture:10%Max
PH:6-8
Smell:Odorless
3.Grade 3
Appearance: white powder
Particle sizes:120-200mesh
KGM:90%Min
Viscosity:30000Mpas
Ash:2.0%Max
SO2:0.5g/kg Max
As:0.5PPM Max
Pb:1.0PPM Max
Moisture:10%Max
PH:6-8
Smell:Odorless
4.High Viscosity Grade Powder
Appearance: white powder
Particle sizes:120-200mesh
KGM:92%Min
Viscosity:36000Mpas
Ash:2.0%Max
SO2:0.3g/kg Max
As:0.5PPM Max
Pb:1.0PPM Max
Moisture:10%Max
PH:6-8
Smell:Odorless
5.High Transparent Grade Powder
Appearance: white powder
Particle sizes:120-200mesh
KGM:95%Min
Viscosity:36000Mpas
Ash:2.0%Max
SO2:0.3g/kg Max
As:0.5PPM Max
Pb:1.0PPM Max
Moisture:10%Max
PH:6-8
Smell:Odorless
Konjac Refined Powder
1.Purificatory Powder
Appearance: white powder
Particle sizes:60-1200mesh
KGM:80%Min
Viscosity:25000Mpas
Ash:2.8%Max
SO2:0.7g/kg Max
As:0.5PPM Max
Pb:1.0PPM Max
Moisture:11%Max
PH:6-8
Smell:Odorless
2.Cleanout Powder
Appearance: white powder
Particle sizes:400-120mesh
KGM:75%Min
Viscosity:20000Mpas
Ash:3.0%Max
SO2:0.7g/kg Max
As:0.5PPM Max
Pb:1.0PPM Max
Moisture:11%Max
PH:6-8
Smell:Odorless
Konjac Powder
1.Superfine Grade
Appearance: white powder
Particle sizes:40-120mesh
KGM:75%Min
Viscosity:24000Mpas
Ash:3.8%Max
SO2:1.6g/kg Max
As:0.5PPM Max
Pb:1.0PPM Max
Moisture:12%Max
PH:6-8
Smell:little
2.First Grade
Appearance: Yellowish powder
Particle sizes:40-120mesh
KGM:70%Min
Viscosity:22000Mpas
Ash:4.0%Max
SO2:1.8g/kg Max
As:0.5PPM Max
Pb:1.0PPM Max
Moisture:12%Max
PH:6-8
Smell:little
3.Second Grade
Appearance: Yellowish powder
Particle sizes:40-120mesh
KGM:55%Min
Viscosity:15000Mpas
Ash:5.0%Max
SO2:2.0g/kg Max
As:0.5PPM Max
Pb:1.0PPM Max
Moisture:12%Max
PH:6-8
Smell:little
Packed in 25kgs net paper bags.
