What food did Belushi spit out when he was a zit?

Has there ever been a definitive answer as to what he put in his mouth and spit out?

We were eating last week and I said something to my 9 year grandson about not pretending he was a zit with the mashed potatoes. He, of course, had no idea what I was talking about. But my son did and laughed. My husband then said that it was not potatoes, but a hard boiled egg that Belushi put in his mouth. We got into a big argument about what the food was.

I looked around the net and found many different ideas as to what it was. Mashed potatoes, hard boiled eggs, cream filled cup cake, etc. But all the ideas seemed to be just that - ideas - as to what the food was. We got out the movie and stopped it as he was holding the food before putting it in his mouth. But we still could not really tell what it was other than it was round, looked bigger than a golf ball and smaller than a tennis ball, was white and had enough body to it to enable him to pick it up without it falling apart.

Because he was able to hold it with his fingers seems to eliminate mashed potatoes, but we never could figure out what it was. Any answers here?.....