We have tried to address your question on our Friday Forum vlog, as well as the Facebook group. Hopefully this helps you.
The water activity (aW) in a almond macaron is typically well below 0.6, due to the high amount of sugar. Mold cannot readily grow without access to water, and as a general guide, needs to be above 0.65 aW. If you are seeing mold on the surface of your macaron, then there is a contamination issue, and also likely a condensation issue.
If what you are trying to do is improve softness to last longer in the center, then there are a number of different approaches possible. Adding mono diglycerides or powdered lecithin may help. Some produces will use a boiled meringue, called an Italian meringue, and replace a portion of the sugar with glucose or corn syrup when cooking.
hopefully this provides you with some useful information.
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.