noun
artificial sweetener
Refers to synthetic sugar substitutes used in foods and drinks.
この飲み物には人工甘味料が使われています。
This drink contains artificial sweeteners.
甘味料 is a general term for sweeteners, including natural ones like sugar. 人工甘味料 specifically refers to artificial sweeteners.
Compound of 人工 (じんこう, 'artificial') + 甘味料 (かんみりょう, 'sweetener').