This year the Chemeca conference was held in Sydney, Australia from 29 September-2 October. At Chemeca, Chemmat’s Dr Kaveh Shahbaz presented slides from his recent study with Prof Mohammed Farid and Angela Yan, Chemmat Part III student. Kaveh’s presentation was entitled ‘Axtaxanthin extraction from crayfish heads using deep eutectic solvents.’

Astaxanthin is one of the most powerful antioxidants in the world and is widely distributed in nature, especially in the marine environment. Astaxanthin also plays an essential role in the pharmaceutical, nutraceutical and cosmetic industries. Crayfish, one of our essential organisms, generally inhabits coastal areas of New Zealand and some of our offshore islands. The proportion of the crayfish head is significantly bigger than that of its tail. However, most meat is in the tail which means a large number of crayfish heads are wasted after consumption, and these contain a certain amount of by-products. We were interested in whether any valuable compounds can be extracted from those wastes.

In the past, various techniques have been introduced to extract Astaxanthin, such as ultrasonic extraction, maceration (organic solvents) and CO₂ supercritical extraction. However, these techniques are complicated and require high capital costs, and some are toxic chemicals. Therefore their application and development has been hindered. Recently, we introduced a new, environmentally clean and cost-competitive process to isolate the Astaxanthin from crayfish heads by designing a new Deep Eutectic Solvent. This solvent is based on ethylene glycol with polarity close to that of Astaxanthin which achieves a high extraction yield compared with conventional solvents, that can be recycled and reused later in the process.