Stability of monoterpenes encapsulated in gum Arabic by spray-drying.

Microencapsulation using spray-drying was tested with gum arabic and monoterpenes as wall and core materials, respectively. Citral, linalool, beta-myrcene, limonene, and beta-pinene were used at concentrations of 10, 20, and 30% with respect to the wall material. The greatest percentages of retention occurred at a concentration of 10%. Linalool and citral presented the greatest losses with increase in concentration. The hydrocarbons used were the most retained. Of the hydrocarbons, beta-pinene was better retained in the capsules than limonene, and beta-myrcene was the least retained of all. The capsules presented similar external morphologies, with no apparent cracks or porosity and an average size varying between 15.7 and 23.2 microm. The stability of the capsules to temperature was monitored for 33 days. The degradation products of the monoterpenes were evaluated. The results indicated a greater stability of the capsules containing beta-pinene and citral than of those containing linalool and beta-myrcene presenting the lowest retentions.