3. Storage stability constraints

One aspect of encapsulation, which may seem trivial but is all too often ignored in the scientific literature, is that a capsule must be able to retain the active ingredient within it, even over a long storage period in the final product and often under demanding temperature conditions, e.g. 3 months at 50°C. This stability constraint is unavoidable for commercial applications. While good performance can be expected from capsules containing freshly encapsulated fragrances, this performance frequently diminishes rapidly within a few days! Unfortunately, there are countless publications that fail to mention this deficiency, which is so easy to identify.

The main causes of a fragrance capsule's loss of performance over time are :

• capsule deliquescence due to dissolution or degradation of the encapsulating material in...