Food safe techniques for cold bonding aluminum for structural support

I am looking for an inexpensive method of bonding reinforcing bars (bar stock, square tube or channel)across the aluminum deck plates of a commercial ice cream display case. The bars will span about 27" and be parallel at approximately 8" on center. The aluminum bars will be bonded to flat aluminum plate about 1/8" thick. I was looking at welding but can't have any distortion of the plate. The joint must be seamless to the extent that it will not allow a space or gap that will harbor bacterial growth.

In the aerospace industry they use phosphoric acid anodizing and adhesives for bonding aluminum. I don't know whether that fits. "Anaerobic sealants" are quite common for sealing lapped or spot-welded joints; there probably are some food-safe ones, although that's not within my experience.