author(s)
Gajendra, Raju CV, Sarojini A, Amitha, Lakshmisha IP and Arun Kumar P

abstract
The squid processing units produces ink sac as processing waste. Squid processing discard can be utilized to obtain the valuable component. In the present study, ink sac from Loligo duvauceli was used to obtain the melanin free ink (MFI). The MFI was characterized for antioxidant properties by analysing Diphenyl-1-picryl hydrazyl free radical scavenging activity (DPPH FRSA), Ferric reducing antioxidant power (FRAP) activity and inhibition of β-carotene bleaching assay. DPPH FRSA activity of 63.21% was observed at 5 mg/ml concentration. The MFI had FRAP and inhibition of β-carotene value of 0.545 and 0.858, respectively. DPPH FRSA, FRAP activity and β-carotene activity increased significantly with increase in MFI concentration. The result indicates that the MFI which can be obtained from the squid ink sac, a waste from squid processing unit can be used as natural antioxidant in many food products to retard the lipid oxidation and shelf-life of the food can also be enhanced.