Isolation and characterization of Astaxanthin from Portunus sanguinolentus (Three spotted crab), Callinectes sapidus (Blue crab) and Paralithodes brevipes (Spiny king crab)

The goal of the present study was to isolate and characterize astaxanthin from Portunus sanguinolentus (Three Spotted Crab), Callinectes sapidus (Blue Crab) and Paralithodes brevipes (Spiny King Crab) using the three different types of solvent mixture such as Hexane: Isopropanol, DMSO: Acetone and acetone. The biochemical composition present in the shells of three crab varieties were evaluated and subjected to the isolation of astaxanthin. The moisture content of three crab varieties ranged between 72.58 ± 0.58 % to 87.67 ± 0.38 % which was higher than other biochemical compositions such as ash, lipid and protein. The yield of astaxanthin from Portunus sanguinolentus (Three Spotted Crab), Callinectes sapidus (Blue Crab) and Paralithodes brevipes (Spiny King Crab) using Hexane: Isopropanol was 31.23± 0.53µg/g, 48.41± 0.28µg/g and 20.15± 0.18µg/g. The yield of astaxanthin using DMSO: Acetone was found to be 29.01±10µg/g, 39.98 ± 0.43 µg/g and 18.06± 0.23µg/g and yield of astaxanthin using Acetone was found to be 19.24± 0.46µg/g, 30.05 ± 0.32µg/g and 12.13 ± 0.16 µg/g. The highest yield was obtained using Hexane: Isopropanol hence, the isolated compound was confirmed to be astaxanthin by TLC. The Rf values in the range of 0.33 to 0.73 was obtained by TLC which confirmed that the isolated extract contains astaxanthin and its esters which is compared with standard astaxanthin. Further, the standard astaxanthin and isolated astaxanthin were subjected to FT-IR, NMR, HPLC and GC-MS for determining the functional groups and predicting the structural conformation. The peak was obtained in FT-IR, NMR, HPLC and GC-MS analysis for isolated astaxanthin and standard astaxanthin which shows the presence of their functional groups. The resultssuggest that astaxanthin isolated from the shells waste of three crab varieties can be used as natural pigments in various field.