Re: what would it take for bread to be packaged free of mold spores?

Mold spores and other microorganisms are abundant in our environment. It is virtually impossible to eliminate microorganisms except in highly specialized situations such as aseptic packaging machines or class 100 rooms or hoods with HEPA filters.

Even in hospital operating rooms there are microorganisms in the environment. Flour has many mold spores naturally present. It is however, possible to prevent these mold spore from growing.

Mold needs oxygen to grow. So if you exclude all of the oxygen mold will be inhibited. There are also many preservatives we can add to food to inhibit or slow the growth of mold such as propionic acid, natamycin, sorbic acid, benzoic acid, fumaric acid, mustard, and vinegar to name only a few.