Stability analysis of zinc oxide-nanoencapsulated conjugated linoleic acid and gamma-linolenic acid

Abstract

Conjugated linoleic acid (CLA) and gamma-linolenic acid (GLA) were encapsulated with hydrated zinc oxide nanoparticles in an effort to improve their time and thermal stability. Encapsulated and nonencapsulated CLA and GLA were stored at 20, 30, 40, and 50°C for 49 d. At various time points, encapsulated CLA and GLA were extracted, methylated, and analyzed using GC-FID. Both encapsulated CLA and control CLA were stable when stored at 20, 30, and 40°C for up to 49 d. However, control CLA was 100% degraded after 28 d at 50°C, whereas encapsulated CLA was stable at 50°C for 49 d. Similarly, both encapsulated GLA and control GLA were stable when stored at 20°C for 49 d, but nonencapsulated GLA was 92% degraded after 49 d at 30°C; encapsulated GLA was stable at 30°C. Therefore, nanoencapsulation improves the time and temperature stability of CLA and GLA. © 2008 Institute of Food Technologists®.