Abstract: A process for packaging units of food in which the food units are placed on a bottom film and slits made in the film. The film with the food units thereon is passed into an open chamber, the chamber closed, and a vacuum drawn on it followed by back-filling with a substantially oxygen-free gas. The film with the food units thereon and a top film over the units is then subjected to vacuum and the top and the bottom films sealed. Alternately the package may be back-filled with oxygen-free gas prior to being sealed about the food unit. The disclosure includes also the steps of partially sealing food units between top and bottom films in a first chamber, back-filling with a substantially oxygen-free gas, then vacuumizing in a second chamber, and fully sealing the packages in a second chamber, or alternately back-filling with the oxygen-free gas before fully sealing.