"The house of Shammai say, a man may not put away his wife, unless he finds some uncleanness in her, according to Deu. 24:1. The house of Hillel say, if she should spoil his food, (that is, as Jarchi and Bartenora explain it, burns it either at the fire, or with salt, i.e. over-roasts or over-salts it,) who appeal also to Deu. 24:1. R. Akiba says, if he finds another more beautiful than her, as it is said, Deu. 24:1 "and it come to pass that she find no favour in his eyes."
(Source: Mishna Gittin, 9.10. See: T. Hieros. Gittin, fol. 49.4; Sota, fol. 16.2; Bemidbar Rabba, 9 (fol. 195.2).)