THE PHYSICOCHEMICAL PROPERTIES OF NANOEMULSIONS CONTAINING CINNAMALDEHYDE (CIN) AT DIFFERENT CONCENTRATIONS (0.025 %, 0.05 %, AND 0.1 %, V/V) AND TWEEN 80 (0.05 %, V/V) WERE INVESTIGATED. ADDITIONALLY, THE EFFECT OF ALGINATE-BASED COATINGS [1.0 %, (W/V), GLYCEROL 0.125 (ML/G ALGINATE)] INCORPORATED WITH CIN NANOEMULSIONS ON THE QUALITY ATTRIBUTES AND SHELF LIFE OF BUTTON MUSHROOMS (AGARICUS BISPORUS) DURING 16 DAYS OF STORAGE AT 4 °C WAS EVALUATED. NANOEMULSIONS WITH A CIN:TWEEN 80 RATIO OF 1:1 REACHED THE SMALLEST DROPLET SIZE (183 NM) AND WERE THE MOST STABLE. THE QUALITY OF THE MUSHROOMS WAS REMARKABLY IMPROVED BY THE INCORPORATION OF CIN NANOEMULSIONS INTO COATINGS, DECREASING THE RESPIRATION RATE, WEIGHT LOSS, PPO ACTIVITY, AND PSEUDOMONAS COUNTS AND INCREASING RETENTION OF FIRMNESS, COLOR, TOTAL POLYPHENOLS, AND ANTIOXIDANT CAPACITY OF MUSHROOMS COMPARED TO THOSE IN THE CONTROL GROUP. THESE RESULTS CAN BE ASSOCIATED WITH THE SMALL DROPLET SIZE OF CIN AND ITS RELATIVELY UNIFORM DISPERSION IN THE COATING. NANOEMULSIFIED COATINGS REPRESENT A PROMISING ALTERNATIVE TO MAINTAIN THE QUALITY OF MUSHROOMS AND EXTEND THEIR SHELF LIFE.