Processing of chitin from crab shells and insect skeletons

Structural formula of chitin.
Structural formula of chitin
Crabs as a renewable source of chitin.
Shrimps as a renewable source of chitin.
Insect cocoons as a renewable source of chitin.
Insect cocoons as a renewable source of chitin.

Chitin is the second most abundant natural polymer on earth: about 1010-1011 tons are produced annually in nature. Due to its high bioavailability, this resource has great potential. It is formed by a variety of organisms, including fungi, insects and crabs as a structural component. Current commercial use is under-represented and focuses solely on isolation from crab shells.

Chitin isolation

Besides enzymatic hydrolysis to chitosan (see enzymatic conversion of chitin from crab shells and insect exoskeletons), our group is working on methods for isolating chitin, which are mainly based on mild chemical and enzymatic processes. Enzymatic processes include the use of individual enzymes or enzyme cocktails to remove contaminants from the chitin matrix.

In contrast, the Industrial Biotechnology Group also pursues the strategy of extracting the desired substance from the matrix by converting chitin into low-molecular chitin or chitosan. Wet-chemical methods are used with the aim of separating impurities as effectively as possible while preserving the chemical-physical properties of chitin. In this context, the preferred use of aqueous media over organic solvents, which require increased safety precautions in an industrial process, should also be mentioned.


Innovative approaches also include the transfer of purification methods from the isolation of other natural substances. For example, chemical-physical processes such as the organosolv process are also used for chitin preparation. An increase in efficiency and thus also a conservation of resources is achieved by a tailor-made process engineering design of the process. The adaptation of the purification process to the respective chitin resource is based on the use of statistical tools, which results in a reduction of waste products in the process. Any by-products are not identified as waste but as the starting point for new value creation. For example, the minerals extracted from the processing of insect and crab chitin could potentially be used as an additive in fertilizers.

The purification techniques we have developed are aimed at being able to produce the products later on in a large-scale process. The calculations required for scaling up are also part of our portfolio.


Hahn, T., Roth, A., Ji, R., Schmitt, E., Zibek, S. 2020. Chitosan production with larval exoskeletons derived from the insect protein production. in: Journal of Biotechnology, Vol. 310, pp. 62-67.

Hahn, T., Roth, A., Febel, E., Fijalkowska, M., Schmitt, E., Arsiwalla, T., Zibek, S. 2018. New methods for high-accuracy insect chitin measurement. in: Journal of the Science of Food and Agriculture, Vol. 98, pp. 5069-5073. Doi:10.1002/jsfa.9044


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Reference projects


February 2021 – January 2024


Expanding the possible applications of renewable raw materials in textile finishing based on the biopolymer chitosan

A project coordinated by Fraunhofer IGB has successfully demonstrated how textiles can be finished using chitosan in combination with bio-based hydrophobic molecules – as an environmentally friendly alternative to perfluorinated chemicals. This innovation could replace PFAS finishes with fewer requirements. The developed formulas have already been successfully adapted to various materials, including paper and cardboard.


January 2021 – December 2023


Treatment of complex process wastewater with bifunctional biobased flocculant

The aim of the LaChipur project is to develop a biobased and functionalized flocculant for the efficient purification of seasonally occurring complex agro-industrial wastewater using residual materials from the food industry. The sustainable flocculant should be customizable to the respective load by varying the composition and thus show optimized efficiency.


August 2017 – January 2021


Bio-based hydrophobic and dirt-repellent finish for the substitution of pPerfluorochemicals (PFCs) on textile surfaces with chitosan derivatives

The aim of the Hydrofichi project is to modify textile surfaces using renewable raw materials in order to replace environmentally harmful and toxic agents that have been used up to now. For this purpose, a chitosan-based hydrophobic finishing of textiles is being developed.


March 2015 – March 2018


Development and production of new insect chitosans and chitosan-based functional coatings for yarns and textiles

The aim of this project is the development of insect chitin as a novel and sustainable source of chitin for use as a functional surface coating for yarns and textile surfaces, especially for technical applications.


November 2011 – October 2014


Development of an integrated biorefinery for the production of special and fine chemicals from waste containing chitin

The aim of this project is to refine fishery waste into nitrogenous platform and basic chemicals via the chitin intermediate.