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Oxidative rancidity in herring and redfish was studied as a function of the applied irradiation dose, the storage time and storage temperature and the packaging conditions.--Measurements of the TBA (thiobarbituric acid) value and the peroxide value were used to evaluate the degree of oxidation of lipids, and were related with sensory scores.--Especially for the fatty fish species (herring) irradiation accelerated lipid oxidation and induced oxidative rancidity. Irradiation of vacuum-packed herring fillets and subsequent storage at +2 degrees C seems to be an interesting process. For the experiments conducted on a semi-fatty fish (redfish), oxidative rancidity was never the limiting factor for organoleptic acceptability.

The retention of l*C-labelled ethyl acetate, n-propanol and acetone in freeze-dried food gels is studied. Fractional retention of the initially present volatiles increases with increasing solids concentration and decreases with increasing initial volatile content. Retention also decreases with increasing sample thickness in fast-frozen samples, and is lower in rapidly frozen than in slowly frozen samples.Humidification causes release of retained volatiles, the new level of retention depending upon relative humidity. The results indicate that the predominant retention mechanism is entrapment in microregions, with a small contribution due to adsorption.

SummaryAmidolytic assay of antithrombin III on capillary blood can validly substitute for similar assays performed on venous blood, as an excellent correlation exists (r = 0.95).For the amidolytic assays of heparin cofactor activity, a much less satisfactory correlation is found (r = 0.81). Results are far more dispersed and a decrease is observed in late capillary samples.Using a low heparin concentration to assay heparin cofactor activity leads to surprisingly high activities for capillary blood. The same type of discrepancy is observed during the earliest stages of clotting of venous blood.

Die vier folgenden analytischen Methoden zur Bestimmung der proteolytischen Aktivität von Waschmitteln und Enzymen wurden verglichen: 1) Spektrophotometrische Bestimmung (im UV) der Abbauprodukte von Kasein; 2) kolorimetrische Bestimmung der Abbauprodukte von Azokasein; 3) polarimetrische Bestimmung (im UV) der Abbauprodukte von Kasein; 4) titrimetrische Bestimmung der Abbauprodukte von Kasein. Die Aktivität der Enzyme kann durch Bestandteile der Waschmittel erhöht oder erniedrigt werden. Stark störend wirkt besonders Perborat. Die polarimetrische Methode ist am genauesten und einfachsten, erfordert aber eine kostspielige Apparatur. Die spektrophotometrische und kolorimetrische Methode sind der titrimetrischen hinsichtlich Genauigkeit und Reproduzierbarkeit überlegen.