 Smoke is both an antimicrobial and antioxidant, however it is insufficient alone for preserving food as smoke does not penetrate far into meat or fish; it is thus typically combined with salt-curing or drying.Smoking is especially useful for oily fish, as its antioxidant properties inhibit surface fat rancidification and delay interior fat exposure to degrading oxygen.Some heavily-salted, long-smoked fish can keep without refrigeration for weeks or months.