EXTRACTION OF MELANIN FREE INK ANTIOXIDANT COMPONENT FROM SQUID INK SAC

Cephalopod forms an important fishery in India. About 5 % of fish landing in Karnataka is contributed by cephalopod fishery. Loligo duvaucelii alone contribute about 38% of cephalopod production in Karnataka. During processing of squid and cuttlefish, the viscera along with the ink sac are generated as by-products. This processing waste has low market value and can create serious pollution and disposal problem if it is not managed properly. Ink sac can be used to produce bioactive component and can have application in functional food ingredient. The antioxidant and antibacterial properties of cephalopods ink are well documented. However, the ink has a black color, which may limit its application. The removal of melanin, a black pigment, prior to utilization not only increases its appeal but also widens its application. Melanin free ink extract can be used as functional ingredient in the fish product to enhance the functionality and to increase the shelf life of the product. In the present investigation melanin free ink was extracted from Loligo duvaucelii  and extracted melanin free ink was studied for its antioxidant activity by measuring Diphenyl-1-picryl hydrazyl free radical scavenging activity (DPPH FRSA) and Ferric reducing antioxidant power (FRAP) activity.

Loligo duvaucelii was procured from Mangalore landing center in iced condition. The ink sac was separated from squid by cutting ink duct and the ink was squeezed out. Squid ink was diluted with cold deionized water (4 ºC) and it was subjected to centrifugation. The obtained supernatant is referred as melanin free ink (MFI). The MFI was characterized for its antioxidant activity by measuring DPPH FRSA and FRAP activity. DPPH activity of MFI was increased with increase in concentration (p˂0.05). FRAP activity also increased with increase in MFI concentration (p˂0.05). The results indicate that MFI can be used as antioxidant component.