Application of Microencapsulation Technology to Improve the Stability of Citral in Rodent Diets

Application of Microencapsulation Technology to Improve theStability of Citral in Rodent Diets. KUHN., G. O., MCCAMPBELL,P., SLNGMASTER, G., ARNESON, D. W., AND JAMESON, C. W. (1991).Fundam. Appl. Toxicol. 17, 635–640. Citral is a widelyused flavoring and scenting agent which is employed in numerousfood, industrial, and household products. Although the currentregulatory status of citral lists it as a GRAS chemical on theFDA list, the chemical is a reactive beta-substituted vinylaldehyde that has been shown to induce irritations of skin andmucous membranes, and to exhibit a dose-dependent teratogeniceffect on embryos of white leghorn chickens. Because of thesefactors, citral was nominated by the National Toxicology Programfor carcinogenesis study. Stability studies of dose formulationsof citral (0.02%) in NIH-07 rodent diet indicated a loss of41% of the citral after 1 day in a rat cage, due mainly to volatilityand reactivity with diet components. The chemical was subsequentlymicroencapsulated using a shell medium of food-grade modifiedcornstarch and sucrose, and then formulated into NIH-07 diet(0.02%) for various stability studies. Results after 7 daysin a rat cage showed 95% retention of chemical; diet that hadbeen stored 21 days retained 95% at 5°C storage and 89%at room temperature. An assessment of the purity of the citralin the microcapsules indicated that total impurities increasedfrom 0.7% in the neat chemical to 1.1% in the encapsulated chemical.