Konjac Gum, Konjac Glucomannan, Konjac Flour, Konyaku, Konnyaku, KGM, E425, 37220-17-0

Konjac Gum, Konjac Glucomannan, Konjac Flour, Konyaku, Konnyaku, KGM, E425, 37220-17-0

Konjac Gum (Konjac Glucomannan – E425)

CAS Number: 37220-17-0
E Number: E425
Chemical Name: Konjac Glucomannan
Synonyms: Konjac Gum, Konjac Glucomannan, Konjac Flour, Konyaku, Konnyaku, Amorphophallus konjac root extract
Source: Tuber (root) of Amorphophallus konjac plant (native to East Asia)

1. CHEMICAL IDENTITY

2. PHYSICAL PROPERTIES

3. THERMAL PROPERTIES

4. SOLUBILITY PROPERTIES

Note: Konjac gum swells rapidly in cold water, achieving up to 200 times its original volume. It forms a highly viscous solution at low concentrations (1% solution provides 20,000-30,000 cP viscosity).

5. CHEMICAL COMPOSITION

Polysaccharide Structure:

• Backbone: β-1,4-linked D-mannose and D-glucose

• Molar ratio (mannose:glucose): 1.6:1 to 1.8:1

• Degree of acetylation: ~5-10% (acetyl groups at C-6 positions)

• Molecular weight: 500,000 – 2,000,000 Da

Key Feature: The acetyl groups along the chain provide solubility in cold water. Deacetylation (by alkaline treatment) allows the formation of strong, thermoirreversible gels.

6. TYPICAL PRODUCT SPECIFICATIONS

7. PRODUCTION PROCESS

8. FUNCTIONAL PROPERTIES

9. KONJAC GELATION MECHANISM

Gelation Mechanism (Alkaline):

• Alkaline pH deacetylates the glucomannan molecule

• Deacetylated chains align and form hydrogen bonds

• Heat (70-90°C) promotes chain alignment and crosslinking

• Result: Strong, thermoirreversible gel (Konjac jelly, Shirataki noodles)

10. APPLICATIONS – FOOD INDUSTRY (E425)

11. APPLICATIONS – VEGAN AND PLANT-BASED PRODUCTS

12. APPLICATIONS – HEALTH AND NUTRITION (Dietary Supplements)

Important Usage Warning: Konjac glucomannan must be taken with at least 8 ounces (240 mL) of water. Without adequate water, it can swell in the esophagus and cause choking or esophageal blockage.

13. APPLICATIONS – COSMETICS AND PERSONAL CARE

INCI Name: Konjac Glucomannan or Amorphophallus Konjac Root Extract

14. APPLICATIONS – OTHER INDUSTRIES

15. SYNERGISTIC BLENDS WITH OTHER HYDROCOLLOIDS

Special Note: The combination of konjac glucomannan with kappa carrageenan (1:1 ratio) produces an elastic, thermoreversible gel that is stronger than either hydrocolloid alone.

16. COMPARISON WITH OTHER HYDROCOLLOIDS

17. SAFETY AND TOXICOLOGICAL PROFILE

GHS Classification: Not classified as hazardous under normal conditions of use.

Side Effects (at high doses >10-15 g/day):

• Bloating

• Gas (flatulence)

• Mild gastrointestinal discomfort

Critical Safety Warning: Konjac gum powder must be taken with adequate water (at least 240 mL/8 oz per 1-3 g). Without sufficient water, it can swell in the esophagus, causing choking or esophageal obstruction. Never take konjac supplements in dry powder form without water.

18. REGULATORY STATUS

FDA GRAS Notice: Konjac glucomannan has GRAS status for use as a thickener and gelling agent in food products.

19. STORAGE AND HANDLING

20. SUMMARY AND CRITICAL INFORMATION

Description: Konjac Gum (Konjac Glucomannan, E425, CAS 37220-17-0) is a natural, water-soluble polysaccharide extracted from the tuber (root) of the Amorphophallus konjac plant. It is a high-molecular-weight dietary fiber composed of β-1,4-linked D-mannose and D-glucose. Konjac gum has an exceptional water-binding capacity (up to 200 times its own weight) and forms very high-viscosity solutions at low concentrations (1% solution yields 20,000-30,000 cP). When treated with alkaline reagents (calcium hydroxide, potassium carbonate) and heated to 70-90°C, it forms strong, thermoirreversible gels (Konjac jelly, Shirataki noodles). Konjac gum also exhibits synergistic gelling properties with carrageenan, xanthan gum, and agar.

Key Advantages:

• Exceptionally high water-binding capacity (200x its own weight)

• Very high viscosity at low concentrations (20,000-30,000 cP at 1%)

• Forms strong, thermoirreversible gels under alkaline conditions (unique among hydrocolloids)

• Synergistic gelling with carrageenan, xanthan, and agar

• Natural, plant-based, vegan, gluten-free

• Prebiotic dietary fiber (supports gut health)

• Zero calories – suitable for weight management

• FDA GRAS and EU E425 approved

Key Limitations/Precautions:

• Critical Safety Warning: Must be taken with adequate water (at least 240 mL per dose) – risk of esophageal blockage/choking

• High doses may cause bloating, gas, or gastrointestinal discomfort

• Hygroscopic – requires dry storage in sealed containers

• Strong gelation requires alkaline conditions (pH > 10) and heating (70-90°C)

• Can be gritty if not fully hydrated (requires proper dispersion techniques)

Major Applications Summary:

Comparison to Other Hydrocolloids:

Synergistic Blends:

Safety Summary:

• Very low acute toxicity (LD₅₀ >5,000 mg/kg)

• GRAS and E425 approved

• Generally safe at recommended doses (1-5 g/day)

• Critical: Must be taken with adequate water to prevent choking

• High doses may cause bloating/gas

Storage: Cool, dry, tightly sealed containers; 24 months shelf life.

Conclusion: Konjac Gum (Konjac Glucomannan) is a unique, high-performance natural hydrocolloid with exceptional water-binding capacity and very high viscosity at low concentrations. Its ability to form strong, thermoirreversible gels under alkaline conditions (used for Konjac jelly and Shirataki noodles) sets it apart from other polysaccharides. It also exhibits synergistic gelling properties with carrageenan, xanthan gum, and agar. As a soluble dietary fiber, it supports weight management, digestive health, and blood sugar and cholesterol management. However, due to its high swelling capacity, konjac supplements must be taken with adequate water to prevent esophageal obstruction. Approved as E425 in the EU and GRAS in the USA, konjac gum is a versatile, natural, and sustainable hydrocolloid for food, health, cosmetic, and industrial applications.