Comprehensive biorefinery of invasive European green crab (Carcinus maenas) into multiple high-value biomolecules

European green crab (Carcinus maenas) is an invasive species globally and is considered marine waste that needs to be eliminated. In this study, the green crab was biorefined via a clean enzymes-assisted bioprocess into multiple value-added bioproducts, i.e., crab oil, minerals, carotenoprotein, and chitin. The recovered crab oil was rich in unsaturated fatty acids such as EPA and DHA as per GC-MS analysis. Citric acid, as a replacement for conventional hash acids, was found to optimally demineralize the crab powder at 1 M and 4 degrees C for 18 h, where the recovered crab minerals identified using ICP-MS showed a high level of calcium, in form of nutritious calcium citrate. Crab carotenoprotein recovered using trypsin exhibited antioxidant properties. It contained 139.26 mu g/g of carotenoids pigment, mainly astaxanthin and astaxanthin diester, as verified by thin layer chromatography, and the protein component in the carotenoprotein was rich in essential amino acids such as leucine via UPLC-MS. The produced crab chitin from papain-assisted deproteinization showed characteristic physicochemical prop-erties following FTIR and XRD analysis. These biomolecules biorefined from the green crab possess wide ap-plications in food, pharmaceutical, biomaterials, etc. This new biorefinery strategy enhances the sustainability for biowaste utilization.

Automated summary

The European green crab has been biorefined into multiple value-added bioproducts, including crab oil, minerals, carotenoprotein, and chitin, through a clean enzymes-assisted bioprocess. These biomolecules have wide applications in various fields such as food, pharmaceuticals, and biomaterials. This biorefinery strategy enhances the sustainability of biowaste utilization.