Spectral changes in fillet of Atlantic salmon as affected by freshness loss and spoilage during cold storage.

Abstract

Spectral effects of microbial growth, packaging atmosphere and heme oxidation were investigated with fresh salmon. The presence of microorganisms and their growth have little effect on the development of spectral features in fresh salmon during storage prior to extensive spoilage. Important spectral changes occur at 606 and 636 nm in the spectra of fresh salmon during storage. Heme oxidation is the primary source of spectral changes occurring at 636 nm in fresh salmon fillets during air storage. The origin of the shoulder peak appearing at 606 nm is absorption due to water in the salmon muscle. The spectral variations at 606 nm depend on the dominant oxidation state of heme in the muscle and the change in the visibility of the water shoulder peak in the spectrum.