From Chitin to Chitosan - Chitosan Based Hydrogels: Functions and Applications - page 32

TAble 1.6
Specifications and Requirements of Chitosan Products

Low Medium High Ultrahigh

DD (%) <75.0 75.0-89.0 90.0-95.0 >95.0

Viscosity (mPa/s) 50-499 500-1000

<50 >1000

Industrial grade
Off-white to yellowish

Food grade
Off-white to yellowish, glossy

Color and luster
Appearance Flaker or powder

Smell Allowing a small amount of natural odor

Water content (%) ≤12.0 ≤10.0

Ash content (%) ≤2.0 ≤0.5

Insolubles (%) — ≤1.0

pH 6.5-8.5

Requirements

Arsenic (mg/kg) ≤1.0

Heavy metals (mg/kg) ≤10

Total colony count
(cpu/kg)

≤1000

Pathogenic bacteria —

TAble 1.7
The Standard of Common Chitosan Products

Items Medical Grade Food Grade Industrial Grade

Appearance Off-white powder Off-white powder Off-white to yellowish

semitransparent flaker
or powder

Deacetylation a degree >90%, 95% >85%, 90%, 95% >70%, 80%, 85%

pH value 7.0-8.0 7.0-8.0 7.0-8.0

Loss on drying <8.0% <10.0% <12.0%

Residue on ignition <1.0% <1.5% <2.0%

Insoluble matter <1.0% <1.0% <2.0%

Heavy metals (count
as load)

≤10 ppm ≤10 ppm

Arsenic ≤0.5 ppm ≤0.5 ppm

Total plate count ≤1000 cfu/g ≤1000 cfu/g

Viscosity b 50-800 mPa/s

Particle size 40 mesh, 60 mesh, 80 mesh, 100 mesh

Packing for medical and food grade: 20.0 kg, 25.0 kg/fiber drum (Φ = 38.0 cm × 48.0 cm or Φ = 42.0 cm × 60.0 cm),
or according to demand.
a They can supply high-purity chitosan with DD > 95%.
b The viscosity is determined at 20°C with 1°C chitosan in 1°C acetic acid.