Stabilization of all-trans-lycopene from tomato by encapsulation using cyclodextrins

The stabilization of all-trans-lycopene from tomato by encapsulation using alpha-, beta- and gamma-cyclodextrins (CDs) was evaluated. To that end, two different encapsulation methods were comparatively studied: a conventional method and a supercritical fluid extraction (SFE) process. An optimization procedure considering distinct molar ratios of CD/lycopene (1/0.0026, 1/0.005 and 1/0.05) as well as the type of cyclodextrin to be used was accomplished. The encapsulation was determined by using micro-Raman spectroscopy. All-trans-lycopene employed was obtained by SFE with a purity around 90-95%. As a result, a molar ratio CD/lycopene of 1/0.0026 was selected as it provided the best complexation yields (93.8%) whilst P-CD seemed to be the most favorable to be used to stabilize lycopene. A comparison of the two methods studied reflected higher encapsulation yields from the conventional method. However, the supercritical fluid approach offers numerous advantages such as the possibility of performing the extraction, fractionation and encapsulation of lycopene from tomato in one step, shortening notably the overall procedure time and minimizing the sample handling. (c) 2007 Elsevier Ltd. All rights reserved.