The question is what kind of preservatives. Formaldehyde is a preservative. Acetic acid is a component of long-ferment lean dough such as sourdough, and an insignificant component of short-ferment (~2 hours) enriched dough, such as sandwich bread. It will not help with enhancement and preservation of texture, in this case the gelatinization of starch in the finished product.

Unless you're suggesting that the pita bread you threw out was preserved with formaldehyde, there isn't much of a question here. Taking issue with bread keeping its freshness is in-and-of itself no bad. If you have issue with a specific preservative, perhaps discuss that specificity.