It doesn’t matter how clean you think your kitchen is, if is it not sterile and hermetically sealed, then every thing produced in will be exposed to microbes. Microbes are in the air. The minute you take your cakes out of the oven, microbes land on the cake. Your cake is moist. Microbes thrive in a moist environment. Mold is an external problem.
You sell your products to the public. Microbes on food can sicken, and in some cases, causes death.
You are running business. No one here is going to take on your product liability problem by advising on preservatives. It is your responsibility to fix.
You need to conduct a shelf life study which includes hiring a qualified food lab to perform food analysis so you can find out the type of mold, and what and how to inhibit it:
This is an example of an outline of a shelf life study. I AM NOT SAYING THIS IS EXACTLY WHAT YOU SHOULD DO. RATHER, THIS IS JUST TO EXPLAIN HOW TO APPROACH A STUDY.
1. Outline objectives of study: what has to be done or possibly be done. For example
- reason for study
- formula change
- packaging change
- development of new product to replace unsellable product
2. Identify cause of deterioration of product. For example
- hire a qualified food laboratory
- perform microbial analysis
- perform water activity level analysis
3. Determine formula. For example
- based on lab analysis
- identify appropriate preservatives
- reformulate and test formula
4. Determine packaging . For example
- based on lab analysis
- identify best packaging
- test reformulated product in new packaging
5. Cost analysis. For example
- perform cost analysis on reformulated product and packaging
- if product is not profitable with increased costs
- increase price or
- discontinue product and develop a replacement product
- other alternatives?