CURING AGENTS AFFECT AMINOPEPTIDASE ACTIVITY FROM PORCINE SKELETAL-MUSCLE

The effect of curing agents (salt, nitrite, nitrate, ascorbic acid, gl ucose and polyphosphates) on the main pure aminopeptidases involved in the release of amino acids during the processing of cured meat produc ts has been studied. Salt strongly inhibited alanyl aminopeptidase and pyroglutamyl aminopeptidase: about 40-50% of their original activitie s were recovered in the presence of 4-5% salt, the typical concentrati on in dry-cured meat products, while leucyl aminopeptidase was not aff ected. However, arginyl aminopeptidase was activated to 2-3 times its control level. Nitrate and nitrite did not affect aminopeptidase activ ity. Ascorbic acid (500 mg/l) slightly inhibited arginyl, alanyl and p yroglutamyl aminopeptidases whereas glucose (20 g/l) activated (to alm ost 5 times its control level) leucyl aminopeptidase activity. Polypho sphates inhibited (25%) alanyl and arginyl aminopeptidases.