In a world I am creating, some people have colonized Ceres-like and Moon-like worlds - that is, they live in domes or underground, in pressurized buildings. The planets have no atmosphere for all practical purposes.
I am now working on such people's cultures, and I'm considering food. Would it be possible to use the vacuum of space to prepare, or at least conserve food?
What I imagine is exposing vegetables to the vacuum of space to dehydrate and freeze them at the same time. One could expose milk to vacuum to remove its water content and get condensed milk. Airlocks could double as cattle slaughtering devices - kill and freeze the meat in one go.
I'm also thinking that all that UV could help kill microbes, if the cold didn't already. Otherwise if radioactivity is an issue, food could be exposed to vacuum underground or in the shade of a hill or mountain.
Would this be feasible, or is it just another ignobel waiting for us to colonize space before it happens?