One
idea is to use invertase, an enzyme derived from yeast, as an ingredient to
bring down water activity in your truffle centers. Additionally, syrups such as
honey will work similarly. Or you may also use potassium sorbate. Talk to your
ingredients suppliers to determine the right amount to use for your specific
truffle recipes.
Do
note that if you claim that your products are all natural, you should pay close
attention to how you choose to extend shelf life of your products. See this story on
a bagel company who received a warning from the FDA for labeling their bagel as
all natural because their blueberries contained potassium sorbate.
