Measurement of fish freshness: Flow cytometry analysis of isolated muscle mitochondria.

Mitochondria are real sensors of the physiological status of tissues. After the death of an animal, they maintain physiological activity for several days. This activity is highly dependent on the availability of nutrients in the tissue.

Mitochondrial activity as an indicator of fish freshness.

The current methods used to routinely assess freshness in the fishing industry reflect more a state of spoilage than a state of freshness. Mitochondria, the seat of cellular respiration, undergo profound changes in post mortem tissues. The objective of this study was to demonstrate that mitochondrial activity constitutes a putative early fish freshness marker.

Use of Ratiometric Probes with a Spectrofluorometer for Bacterial Viability Measurement.

Assessment of microorganism viability is useful in many industrial fields. A large number of methods associated with the use of fluorescent probes have been developed, including fluorimetry, fluorescence microscopy, and cytometry. In this study, a microvolume spectrofluorometer was used to measure the membrane potential variations of .

Assessment of freshness and freeze-thawing of sea bream fillets (Sparus aurata) by a cytosolic enzyme: Lactate dehydrogenase.

The evaluation of freshness and freeze-thawing of fish fillets was carried out by assessment of autolysis of cells using a cytosolic enzyme lactate dehydrogenase. Autolysis plays an important role in spoilage of fish and postmortem changes in fish tissue are due to the breakdown of the cellular structures and release of cytoplasmic contents. The outflow of a cytosolic enzyme, lactate dehydrogenase, was studied in sea bream fillets and the Sparus aurata fibroblasts (SAF-1) cell-line during an 8day storage period at +4°C.

Chemical structure and biological activity of a highly branched (1 → 3,1 → 6)-β-D-glucan from Isochrysis galbana.

A highly branched (1 → 3,1 → 6)-β-D-glucan was isolated from the microalga Isochrysis galbana Parke (Isochrysidales, Haptophyta). The polysaccharide structure was analyzed by methylation and Smith degradation, as well as by ESI and MALDI TOF mass spectrometry and NMR spectroscopy. The glucan was shown to contain a (1 → 6)-linked backbone, where every residue is substituted at position 3 by Glc, which in turn may be substituted at C-6 by a single Glc or by rather short (up to tetrasaccharide) oligosaccharide chains.