What is Konjac? Konjac flour, Uses, Safe, Benefits, and Side Effects

What is Konjac? Konjac flour, Uses, Safe, Benefits, and Side Effects


Table of Contents

Konjac is a glucomannan substitute made from the Japanese root of the konjac plant (Amorphophallus konjac). Konjac flour is often used to replace gluten in order to create wheat free and gluten free products. It is also commonly found in vegan and vegetarian recipes.

Konjac flour is the premium food that is obtained from the root of the Konjac plant which is used for weight loss and improving health. The flour consists of 90% protein that makes it a healthy meal for your body. It does not create any adverse effect on your body if you eat it on daily basis. On the other hand, Konjac flour also has numerous benefits that were documented by various researches related to health.

What is konjac?


Konjac is a type of plant that grows in the form of a tuber. These tubers can be used to produce flour and noodles. Konjac comes from the plant Amorphophallus konjac, which is native to Japan.

The konjac plant has been used in traditional Chinese medicine for centuries and is considered one of the top 10 herbs used in Chinese medicine today. Konjac has been shown to have many health benefits including lowering blood sugar levels and cholesterol, improving immunity, preventing heart disease and relieving constipation.

Konjac flour is derived from ground konjac powder or konnyaku flour, both of which are made from the root of konnyaku or kuzu roots. It has been used as a food ingredient for thousands of years throughout Asia and Europe. It is also known as glucomannan or soluble fiber because it can increase stool weight by absorbing water.

Konnyaku flour contains about 75% water-soluble fiber called glucomannan that provides most of its physiological effects on digestion such as lowering serum cholesterol levels, and preventing constipation by increasing stool weight.

What is konjac in food?


Konjac is a pure vegetable fiber that is naturally high in fiber and low in calories. It has been used for centuries to make foods like jelly, noodles and desserts. Konjac flour is made from the root of the konjac plant. Konjac flour contains no gluten and can be used as an alternative to wheat flour in gluten-free baking.

Benefits of Konjac Flour

Konjac flour has many health benefits including:

Low Carbohydrate Content – Konjac flour has a very low carbohydrate content which makes it an ideal ingredient for those following a low-carb diet or those who want to reduce their intake of carbohydrates without sacrificing taste or texture.

High Fiber Content – One cup of konjac flour contains 11 g of fiber which makes it an excellent source of fiber to help maintain healthy digestion and keep blood sugar levels steady throughout the day!

No Gluten – Konjac does not contain gluten so it is an ideal substitute for those who are sensitive to gluten or are following a gluten-free diet.

What is konjac gum?


Konjac gum, also known as glucomannan, is a soluble fiber made from the root of the konjac plant. It is used as a thickening agent in foods and beverages.

Konjac gum is not digested by humans and passes through the digestive system unchanged. It can also be used as a dietary fiber supplement to promote regularity and help maintain a healthy digestive tract.

Konjac gum has been used for centuries in Asia for its medicinal properties, including promoting weight loss and lowering cholesterol levels. There are no known side effects of konjac gum, but it should not be taken by people with certain medical conditions or those taking certain medications.

What is konjac glucomannan?


Konjac glucomannan is a dietary fiber, also known as shirataki, made from the root of the konjac plant. It’s often used in Japanese cooking.

Konjac glucomannan is a dietary fiber, also known as shirataki, made from the root of the konjac plant. It’s often used in Japanese cooking. The fiber comes in two forms: konjac flour and konjac flour with hydrocolloids (or “glucomannan”).

Konjac flour is pure ground konjac root. It has no taste or smell and can be found in any health food store that carries Asian ingredients. Konjac flour with hydrocolloids has been treated with acids or enzymes to make it more soluble in water and easier to use in recipes. You can find this particular form at most supermarkets in the refrigerated section by the tofu or tempeh — look for packages marked “konjac glucomannan” or something similar

What are konjac noodles?


Konjac noodles are a gluten free, vegan alternative to pasta made from the root of the konjac plant. They are very low in calories and carbs, with 1/4 cup providing only 20 calories and 2g of carbs. They are also very high in fiber and protein, with 1/4 cup containing 1g of fiber and 3g of protein.

Konjac noodles have a crunchy texture similar to al dente pasta. They can be eaten raw, but they don’t have much flavor on their own so it’s best to cook them with sauce or vegetables.

Some people find that konjac noodles take a long time to soften in hot water, but if you soak them in cold water for 10-15 minutes before cooking they’ll become softer more quickly (and you won’t need as much salt).

What is Konjac flour?


Konjac flour is a plant-based, gluten-free flour that makes a great substitute for wheat flour in baking and cooking.

Konjac flour is made from the konjac root, a vegetable that grows in Asia. The root is dried, ground into a powder and then added to baked goods and other recipes as a thickener and binding agent. Konjac flour has no flavor or color, so it doesn’t change the taste or texture of the food it’s used in.

The benefits of using konjac flour include:

It’s low in calories but high in fiber, so it can help you feel fuller longer.

It can be used as a substitute for wheat flour to make gluten-free products.

Konjac flour has no fat or cholesterol, making it an excellent option for those who are watching their weight or have heart disease or diabetes.

What are the types of konjac flour?


It is made by grinding dried konjac slices/chips. There are three types of glucomannan based on the purification process: common konjac flour, konjac gum, and konjac glucomannan.

A konjac flour’s color is an important indicator of its quality. Whiter the color, the more glucomannan it contains.

1. Common konjac flour


This refers to unpurified konjac flour with the following properties:

  • Smell: faint sulfur dioxide smell and the inherent aroma of konjac.
  • The appearance of the particles is white, with particles of yellow, brown, or black color with small amounts of yellow.
  • Starch and cellulose are removed through a very simple purification process.
  • No less than 65% glucomannan content.
  • Velocity: 14,000 mpa.s
  • Size of mesh: commonly 40-120mesh and above 120mesh.

2. Konjac gum


Aqueous extraction of konjac flour is used to produce pure konjac flour. Because it is not claimed to be dietary fiber, it has no physiological benefits.

  • It has an inherent konjac smell.
  • Powder appearance ranges from white to cream to light tan.
  • No less than 75% glucomannan content.
  • It has a viscosity of about 23,000 mpa/s.

3. Konjac Glucomannan


Amorphophallus konjac cell walls contain hemicellulose, which is the main component of konjac glucomannan (KGM). In addition to being a dietary fiber, it is also water-soluble.

An excellent hydrophilic, gel-forming, emulsifying, film-forming, and thickening polysaccharide, KGM is a natural high-molecular-weight polysaccharide.

It is for these reasons that KGM is used in food in a wide variety of applications.

Manufacturing process

In order to produce glucomannan, konjac flour is cleaned with water-containing ethanol, as it is easily absorbed by water and insoluble in alcohol.

Through ethanol precipitation, glucomannan is isolated from starches, cellulose, protein, and other components. Following centrifugation, milling, drying, and other processes, pure KGM is obtained.


D-mannose and D-glucose units are linked together by b(1-4)-glycosidic bonds in glucomannan.




Other names
  • Konnyaku
  • Yam flour
  • Konjac mannan
  • Elephant yam
CAS number37220-17-0
Chemical formulaC24H42O21 (Glucomannan)
Molecular weight200,000–2,000,000 (konjac gum)500,000–2,000,000 (konjac glucomannan)





In spite of konjac’s large molecular weight, its large number of hydroxyl groups allow it to absorb around 80-100 times its own quantity of water.



Highest viscosity

After swelling and hydrating in water, konjac forms highly viscous solutions. At the same concentration, 1g of konjac dissolved in 100g of water can produce 20,000cps to 40,000cps of viscosity, the highest viscosity among thickeners,  xanthan gum, carrageenan, and gum arabic are examples.

Since konjac is a nonionic polysaccharide, its viscosity and gel structure is less affected by salt ions (calcium, potassium, or sodium ions) than guar gum, locust bean gum, and xanthan gum.

As a result of its high viscosity, it is effective as a thickening agent in sauces, soups, and dressings.


Xanthan gum and starch have a synergistic thickening effect. In combination with 0.02% to 0.03% konjac, 1% xanthan gum can increase solution viscosity 2 to 3 times. When modified corn starch is mixed with 0.5% konjac, its viscosity is 4-9 times higher than when modified corn starch is mixed with 4.5% modified corn starch. As a result, konjac in food can reduce the need for additional thickeners.



Thermally irreversible gel

An alkaline condition (e.g. calcium hydroxide) can cause konjac to form a thermally irreversible gel. Acetyl groups in water molecules determine its degree of gelling.

With alkali and heat, acetyl groups are removed, forming gels. Besides being thermally stable, this gel is acid and salt resistant.

In addition to calorie-free noodles (shirataki), tofu, rice, pudding, etc., konjac products can also be flavored.

Thermally reversible gel

By heating, a solution containing konjac, xanthan gum, gellan gum, carrageenan, or other hydrocolloids, gels can be formed that is thermally reversible.  As a result of gelling’s synergetic effects.

What is the application of konjac?


The following are some common uses of konjac as a gelling agent:

  • Pasta
  • Noodles
  • Prepared meals
  • Jellies
  • Jams

It is also used as a thickener and stabilizer in bread, cakes, meat products, ice cream, and beverages.


With its thickening, emulsifying, water retaining, and gelling properties, konjac is used in meat as a binder. As a substitute for fat, it is often used in sausages and ham. It improves the texture of meat and reduces fat content while increasing water holding capacity.

Starch products

In addition to improving gelatinization, rheological properties, and texture properties of starch, konjac also agglomerates and crosslinks starch. Food quality, texture, and taste are closely related to these properties. Konjac and starch blends have a better thickening and stabilizing effect. As a result, the gel formed by the mixture is less hard and elastomeric.

When konjac is added to convenient rice, it improves the mouthfeel and makes it taste more like fresh rice.

What are the konjac health benefits?


According to the FDA, konjac glucomannan is a nondigestible carbohydrate that has been classified as a dietary fiber. The following health benefits can be attributed to dietary fiber:

  • Glucose, blood pressure, and cholesterol levels are lowered
  • Increasing laxative efficacy
  • Taking in fewer calories

Weight loss can also be achieved by consuming glucomannan.

Is konjac safe to eat for the body?


Almost no side effects are associated with this natural ingredient. A number of federal agencies have approved its safety, including the FDA, the European Food Safety Authority (EFSA), and an expert committee of FAO and WHO on food additives (JECFA).



The FDA considers konjac flour as a GRAS (generally recognized as safe) food additive.



It is listed in Commission Regulation (EU) No 231/2012 as an authorised food additive and classified under “additives other than colours and sweeteners”. There is a limit of 10 g/kg for their applications in “Group I”.

Safety re-evaluation in 2017


In its studies on carcinogenicity, genotoxicity, and other factors, the European Food Safety Authority concluded that no numerical acceptable daily intake (ADI) was required for konjac gum (E 425 i) and konjac glucomannan (E 425 ii) as food additives and that there were no safety concerns under 10 grams per kilogram of consumption.


According to JECFA, konjac gum and konjac glucomannan are both categorized as konjac flour for emulsification, gelling, stabilizing, and thickening.

In 1996, the ADI was set as “not specific”.

What is konjac made of?


Konjac products are made from the konjac plant, which is a root vegetable that grows mainly in Asia. The root is ground into powder, then combined with water and other ingredients to create a gel.

Konjac powder is made from the konjac plant, which is native to Japan and China. The root of this plant has been used for centuries in East Asian cooking for its texture and taste.

The konjac plant grows in nutrient-poor soil, so it absorbs more nutrients than other crops do. This means that konjac products contain more fiber than most other foods. In fact, 100 grams of cooked konjac root contains about 18 grams of fiber — more than twice as much as cooked broccoli.

Is konjac bad?


There are conflicting reports about whether konjac is healthy or unhealthy. It depends on what study you’re reading and who’s funding it. Some studies have claimed that konjac has caused diarrhea in some people who eat it regularly; others have found that it has no adverse effects at all. If you’ve been eating konjac regularly with no ill effects, then chances are that it’s safe for you to continue eating this food if you want to do so.

What are konjac side effects?


Konjac root is a vegetable that has been used in the Far East for centuries. It is known for its high water content, which makes it an excellent vegetable to use when you are trying to lose weight.

Konjac root has also been used to help with constipation, diarrhea and other digestive issues. However, konjac root can cause some side effects if taken improperly or in large amounts.

The following are possible konjac side effects:


Allergic reaction. If you’re allergic to konjac root powder, you may have an allergic reaction after using this supplement. Signs of an allergic reaction include hives, swelling and itching of the skin, and trouble breathing. Call 911 or seek emergency medical care if you experience these symptoms after using this supplement.

Heartburn and reflux disease. Konjac root powder may cause heartburn and reflux disease (GERD) in some people, especially if you take this supplement with food or beverages that contain caffeine or alcohol. You should avoid these substances while taking this supplement to prevent heartburn and reflux disease from occurring.

Diarrhea. Konjac root powder may cause diarrhea when taken by mouth in large amounts or for long periods of time (months). Diarrhea can lead to dehydration because it causes fluid loss through frequent urination or stool leakage. The most common causes of diarrhea are infections, lactose intolerance, and food allergies, but konjac root powder can also cause diarrhea as a side effect in some people who take it orally over a long period of time (months).

Where to buy konjac?


You can buy konjac from Amazon.com, eBay, Walmart, and Aliexpress.

Amazon has a wide range of konjac products in different shapes, styles, and prices. The best thing is that they offer free shipping on most of their products to the US and Canada. You can also try eBay or Aliexpress if you have time to wait for the package to arrive at your home.

If you buy large quantity konjac, you can consider purchasing from Grade Chemical which is one leading food chemical suppliers in China.



If you have read this article, you should know that konjac flour is a good substitute for wheat. It definitely has a good amount of health benefits, such as reducing cholesterol, keeping blood sugar level and good for digestion. This flour can be used in many cooking methods, so the more you use it, the healthier and more delicious your food will become!

In this prepared statement, we will provide a thorough analysis of what konjac flour is, what it is used for, who can benefit from using this product, possible side effects, and precautions to consider if you are thinking about using it.

What kinds of comments have you found about konjac, feel free to contact us in the comments.

Sophie Feng

Sophie Feng

Sophie Feng is the author of gradechemical.com, she is the co-founder of the grade chemical network. She has been in grade chemical company since 2017, with a working knowledge of food chemical .

Recent Post:

Leave a Comment

Your email address will not be published. Required fields are marked *


One professional food chemical manufacturing company in China, we can supply different types of food additives, flavors fragrances, feed additives, food ingredients, and custom chemicals, etc

Fill out the form and our sales team will contact you with our best prices.

Scroll to Top

Ask for Quick Quote

We will contact you within 1 working day, please pay attention to the email.