BETA-HYDROXYACYL-COA-DEHYDROGENASE (HADH) ACTIVITY OF UNFROZEN AND FROZEN-THAWED FROG (RANA-ESCULENTA) LEGS

The beta-hydroxyacyl-CoA-dehydrogenase (HADH) activity of unfrozen and thawed frog legs was investigated. The enzyme was extracted by either immersing frog legs in phosphate buffer 0.1 M, pH 6.0 at 25 degrees C for 15 min or pressing them between trichinoscopy glasses. The enzyme activity was assayed using acetoacetyl-CoA as substrate and measured spectrophotometrically at 340 nm. It was possible by both extraction m ethods to distinguish between thawed and unfrozen samples although whe n the juice was obtained by pressing the HADH activity of the dilution was similar to 1.5 times higher than that obtained by immersion. The HADH activity was significantly higher (P < 0.001) in frozen-thawed fr ogs than in unfrozen legs because during freezing there is a release o f HADH. No significative differences were found in the HADH activity i n samples frozen in the temperature range -10 to -196 degrees C. HADH activity was not affected by the storage time in crushed ice up to 6 d ays.