Azeotropic Distillation Starting from Fresh Vegetable Materials,an Interesting Alternative to Simple Extractionfrom Vegetable Dried Sources

摘要

The present work aims to realize a comparative study concerning the contents of the free radical scavengers compounds and antioxidant activities of two series of concentrated extracts: one obtained by azeotropic distillation from fresh material and the other starting from dried sources by a simple extraction proceeding. The two series of concentrated extracts are obtained from various, fresh and dried materials: seabuckthom (Hippophae rhamnoides) fruits, french marigold (Tagetes patula) flowers, tomatoes (Lycopersicum esculentum) fruits, common pot marigold (Calendula officinalis) flowers, carrot (Daucus carota) root. Those extracts were analyzed for carotene derivatives and polyunsaturated fatty acids contents and for their antioxidant activities, using UV-VIS spectrometry, High Performance Liquid Chromatography, Gas-Chromatography and biochemical methods. The carotene derivatives contents appreciated by UV-VIS spectrometry, were found not to be in a correlation to their antioxidant-free radicals scavenging activities established by biochemical methods. A large variety of carotene derivatives were identified by HPLC in all concentrated extracts. For the extracts obtained from the same vegetal material, the study emphasized that the contents in carotene derivatives, established by UV- VIS spectrometry, and the antioxidant activities were higher for the extracts obtained starting from fresh material, by azeotropic distillation, than those obtained from dried vegetals by common solvent extraction. The contents in polyunsaturated fatty acids in seabuckthom extracts obtained by GC and derivation, proved to be the same for both proceedings.