A friend and I are hoping to start a small cookie business and we are having trouble extending the shelf life of our products to two weeks. We use no preservatives or margarine, and are nut-free. We have tried several natural preservatives (e.g., citric acid), playing around with the recipe to increase/decrease the salt and/or butter, chilling the dough, and other techniques, but have had no luck. The cookies last for only one week and then start to taste rancid/stale. Any suggestion to increase the shelf life would be really appreciated.
On a somewhat related note, is there such an occupation as a food engineer who works on these kind of issues? If yes, how does one find a fairly inexpensive, yet reliable food engineer?