How is food symbolic in The Importance of Being Earnest?

In the play, there are several places which indicate that a character's relationship with food seems to be symbolic of their adherence to, or failure to abide by, social rules and conventions. For example, there are cucumber sandwiches—Aunt Augusta's favorite—before she arrives, but Algernon eats them all and refuses to share any even with his friend Jack. Algernon knows that they are his aunt's favorite, and yet he eats them anyway. Then, he blames his butler Lane for their absence and compels Lane to lie for him. Algernon tells his aunt, "I am greatly distressed, Aunt Augusta, about there being no cucumbers [for sandwiches], not even for ready money." We see, through this exchange, that Algernon is rather selfish and self-centered, and that he is quite willing to deceive for even the smallest pleasure. He will not conduct himself according to the rules of good society.
We can juxtapose this with Aunt Augusta's admission that she had "some crumpets with Lady Harbury," a nod to her own willingness to not only abide by but also attempt to uphold the social mores of the upper class. She eats when it is proper. Further, later in this scene, Algernon tells Aunt Augusta that he will not be able to attend her dinner party that very night, despite her concern that his absence "would put [her] table completely out." In other words, Algernon is again refusing to abide by typical social convention, backing out of the dinner at the last minute and throwing off Lady Bracknell's place settings and seating. He has created an imaginary invalid friend named Bunbury, a total fiction that he has dreamed up in order to get out of social functions that he doesn't want to attend, like the dinner. Such a creation would be considered uncouth and strange by society, and it helps to underscore Algernon's unwillingness to do what is expected of him and his class.
Later, at Jack's country estate, his disagreement with Algernon over how and when one should eat extends this symbolism. Both men are upset about their ruses being discovered by the women they love, and they begin to argue. Algernon starts eating the muffins, which Jack criticizes because he thinks that it makes Algernon seem "perfectly heartless." It seems, then, that—by convention—those who are in "horrible trouble" are supposed to not want to eat. Algernon, on the other hand, says,

Indeed, when I am in really great trouble, as any one who knows me intimately will tell you, I refuse everything except food and drink. At the present moment I am eating muffins because I am unhappy. Besides, I am particularly fond of muffins.

Therefore, Algernon's food habits again establish him as being one who ignores social convention. Not only is he eating muffins at this particularly upsetting time, but he is, according to Jack, eating all the muffins in a very "greedy way." Double the offense!