First thing I thought of is a sawzall too, but now I'm imagining a few problems. How do you clean it effectively? Lots of them use rubberized/textured grips that I could see being difficult to properly clean, plus the vents to let the motor cool don't love water being introduced. How do you keep food residue from bunching up inside the tool? The one in my garage always has leftover sawdust along the mechanism where the blade goes into the tool. How does the employee use it while also handling food? Do they touch the frozen food and then pickup the tool, hopefully leaving the tool in a safe tray of some sort between handling? Is it efficient enough for the number of cuts the employee needs to make during a shift? So on, so forth...
I think I'd opt for a bandsaw. Take a look at the butchering setups, check some yt videos for examples, but that seems the cleanest and safest method (for food and employee safety).