Treatment composition with delivery particles made from acid-treated chitosan

A treatment composition comprising a treatment adjunct and a population of delivery particles,

• wherein the delivery particles comprise a core and shell surrounding the core,
• wherein the core comprises a benefit agent,
• wherein the benefit agent comprises a fragrance material,
• wherein the shell consists of a polymeric material that is a reaction product of an acid-treated chitosan and at least one cross-linking agent,
• wherein the acid-treated chitosan results from treating chitosan with a mixture of a first acid and a second acid,
• the first acid is a strong acid,
• the second acid is a weak acid,
• wherein the first acid and the second acid are present in a normality ratio of from about 35:65 to about 65:35,
• wherein the chitosan is treated with the mixture at a pH of 6.5 or less, and at a temperature of at least 25° C.,
• wherein the at least one cross-linking agent is polyisocyanate, and
• wherein the treatment adjunct comprises a conditioning active.