Method of improving stability of sweet enhancer and composition containing stabilized sweet enhancer

A liquid composition comprising

• a compound having structural formula (II), or a salt or solvate thereof;
• and
• a phenol-based antioxidant, or a salt or solvate thereof, as a photostabilizer for the compound having structural formula (II);
• wherein:
• the phenol-based antioxidant is selected from the group consisting of a dihydrochalcone derivative, a flavanone derivative, a coumarine derivative, a phenylpropenoic carbonyl compound, and a combination thereof;
• the compound having structural formula (II):
• wherein,
• A is —OR9, —NO2, —NHOR9, —NR9COR10, —NR9R10, or —NR9CO2R10;
• R17 is hydrogen, alkyl, or substituted alkyl;
• X1 is —O—, —NR9—, or —S—;
• X2 is alkylene, substituted alkylene, heteroalkylene, or substituted heteroalkylene;
• m is 1;
• Y1 is
• X3 and X5 are independently a covalent bond, —O— or —NR9—;
• X4 is O;
• Rx is halo, —NO2, —CN, —OH, —NH2, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl or substituted heteroarylalkyl;
• n is 0, 1, 2, or 3;
• Ry is hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl or substituted heteroarylalkyl, —NR9R10;
• and
• each R9 and R10 is independently hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl or substituted heteroarylalkyl.