Changes in muscle subcellular fractions of baltic herring (Clupea harengus membras) during cold and frozen storage

Abstract

The autolytic enzymic degradation of the muscle of Baltic herring (Clupeu hareugus membrus) was studied by investigating the muscle fractions after two different types of storage corrimonly used in fish handling, i.e. freezing and storage at -3 0 T , and storage at +5"C, comparing them with the muscle fractions of fresh fish. Nuclear, mitochondrial, lysosomal and microsomal as well as soluble fractions were studied by assaying the activities of lysosomal cathepsin D and mitochondrial cytochrome c oxidase. The rnorphology of sedimented fractions as revealed by electron microscopy compared with the enzymic results. After storage, the marker enzymes were detected in the more s!owly sedimenting fractions. Freezing and thawing also resulted in the lysis of mitochondria and lysosomes and in a loose, disorganised muscle structure.

Effect of harvesting stress and storage conditions on protein degradation in fillets of farmed gilthead seabream (Sparus aurata): A differential scanning calorimetry study

“…In the present study, cathepsin B activity was significantly higher for fresh seabream. When muscle is frozen, the formation of ice crystals leads to the rupture of lysosomes, causing the release of enzymes into the muscle fibres (Karvinen, Bamford, & Granroth, 1982). The method used in this study destroys the lysosome membranes during extraction and uses a synthetic substrate, effectively measuring the proteolytic potential of lysosomal enzymes present.…”

Frozen herring as raw material for spice-salting

“…Freezing and thawing of ®sh are known to cause rupture of cellular membranes, lysis of organelles such as mitochondria and lysosomes, and liberation of otherwise bound enzymes. 20,21 A rupture of the acinar cells in the intestine and pyloric caeca may cause leakage of proenzymes of the dominating intestinal proteases, such as trypsin and chymotrypsin, into the intestinal lumen. This may increase the activation rate of these enzymes during thawing.…”

THE BIOCHEMICAL AND SENSORY PROPERTIES OF GILTHEAD SEA BREAM (SPARUS AURATA) FROZEN AT DIFFERENT CHARACTERISTIC FREEZING TIMES

“…1979). Therefore, freezing and thawing may cause lysis of organelles, such as mitochondria and lysosomes, and disintegration of membranes, resulting in a loose, disorganized fish muscle structure (Karvinen et al. 1982).…”