Juicer's food pusher's bottom just sliced off, now it's an empty cylinder
If buying the new one is not a viable option for you, then without knowing the exact type of plastic used in the old one, the only "food safe" multi-purpose adhesives will be either a silicone seal type, which is soft and flexible, so may not work under force, or a two part epoxy type hard bond material. That will take longer to cure, but will likely do the job and is what I would recommend. 

This is just an example, not an endorsement, although Permabond is a well known company with a decent reputation.
https://www.permabond.com/2015/03/02/food-grade-adhesives-permabond/

It's worth noting however that the likelihood of your finding the Food Safe versions in a local hardware store are low, and the cost is going to be roughly the same as buying the new pusher on-line. So were it me, I would just replace it.