Effect of water activity on the stability to oxidation of spray-dried encapsulated orange peel oil using mesquite gum (Prosopis juliflora) as wall material

Mesquite gum solutions (30% w/v) were used to emulsify orange peel oil in an oil-gum solids ratio of 0.25. Emulsions were spray dried in laboratory scale equipment. The powders were stored in a(w) (s) from 0.108 to 0.743 at 35degreesC. Quantitative analysis of limonene oxide indicated that the sample at 0.628 showed a very good stability against oxidation after thirty d, without caking and stickiness occurring. At this water activity the system was within rubbery state, and the moisture content corresponded to that of the minimum integral entropy.