Raman analysis of white spots appearing in the shell of Argentine red shrimp (Pleoticus muelleri) during frozen storage

Abstract

We report on the Raman spectra of white spots formed during frozen storage of shrimp on the shell in Pleoticus muelleri argentine, measured in situ. From Raman analysis this study determined that ikaite is the predominant calcium carbonate crystal formed on the inner shell side, while ikaite crystals are accompanied by significant amounts of calcite on the outer side. Calcite could be a dehydration compound appearing during sample preparation. On the basis of data from Raman spectroscopy, there seem to be no significant protein and/or chitin conformational changes accompanying the precipitation of ikaite.