Finely ground samples (3g) of thawed fillets were homogenized
with 27 ml of 0.6 M KCl buffer (pH 7.0, 20 mM Tris-HCl) before
centrifugation at 20,000g at 4 °C for 30 min. So of the supernatant was
determined by ANS reagent (pH 7.4, 8×10−3 M ANS, 0.1 M sodium
phosphate buffer)