There has never been a clear answer, but in [https://meta.ifixit.com/Answers/View/11772/What+is+the+clear+substance+made+of#answer11783|2018] it was declared to be non-toxic. Best advice in your case is throw the baby food that’s been open around it away if you want to be safe unless there’s information about what’s in it posted.
[https://meta.ifixit.com/Answers/View/14075/How+to+safely+dispose+of+a+punctured+iOpener|In this post], it seems to be a glycerol formulation. It shouldn’t be a problem, but if you’re still leery it’s better to be paranoid in cases like this.
