Is there a method to estimate water activity?
I have seen the charts with water activity (Aw) for various cosmetic and food products. But would it be possible to design a W/O emulsion with 10% water and a Aw of 0.75?
If I knew the Aw of normal saline and seawater can I use this to estimate the decrease in Aw salt would provide at a given concentration? I think this can be done for an aqueous saline solution, but what about saline solution as part of a W/O emulsion?
Would a saturated sodium chloride solution Aw=0.75 in a W/O emulsion yield an emulsion with Aw of 0.75?
If you also add other chemicals that lower Aw (glycerin or salt) can you estimate the cumulative effect?
Thanks for your help!
I think I posted this is the wrong place but cannot figure out how to move it! Sorry!