Color Development of Squid Skin as Affected by Oxygen Concentrations

Abstract

Color development of squid skin was controlled by O2 concentration for storage. When stored above 10% O2, the color index (CI) as an index of color development of skin increased in 24 h, and decreased gradually with further storage. The CI profile at 10% O2 was practically identical to that in air. When stored at 0.1% O2, in the presence of N2, the CI increased partly in 6 h and decreased. Morphological observation of chromatophore distinguished the CI increase at 0.1% and 10% O2 by their shape and size distribution. However, the storage of squid at O2 concentration between 2.5% and 7% practically did not change the CI for at least 48 h. ATP content of skin was kept unchanged when the storage atmosphere contained O2 concentration at 2.5% up to 48 h, while the content decreased rapidly with a half decrease in 6 h when stored at 0.1% O2. It was demonstrated clearly that ATP is regenerated in the presence of O2, but the ATP concentration did not determine the CI change during the storage. Exposure to high concentration of O2 might induce a full color development of squid skin.

Characterization of the Jumbo Squid (Dosidicus gigas) Skin By-Product by Shotgun Proteomics and Protein-Based Bioinformatics

“…The most prominent classes were oxidoreductases (37.0%), nucleic acid binding proteins (12.1%), hydrolases (12.1%), calcium-binding proteins (12.1%), transferases (9.8%), and enzyme modulator (9.8%). Thus, in the jumbo squid skin, oxidoreductases are mainly involved in the energetic metabolism, antioxidant defense and cephalopod coloration [38]. Another significant protein class is that of calcium-binding proteins, which are involved in muscle relaxation and nervous transmission in the marine skin species [39,40].…”