sweetening vs sweetener

sweetening and sweetener both are nouns.

Word	Noun	Adjective	Verb	Adverb
sweetening	Yes	No	No	No
sweetener	Yes	No	No	No

As nouns, sweetening and sweetener are synonyms defined as:

sweetening and sweetener: something added to foods to make them taste sweeter

sweetening (noun)	sweetener (noun)
the act of adding a sweetener to food	anything that serves as an enticement
an improvement that makes something more agreeable	something added to foods to make them taste sweeter
something added to foods to make them taste sweeter