Studies On Chemical Components Of Garlic Peel And Antioxidant Activity Of Garlic Peel Extract

Garlic, as a traditional edible plants for Chinese medicine, has already attracted more and more attention of worldwide scholars and scientists because of its excellent pharmaceutical function. Garlic peel, as the low utilizating by-product of garlic deep processing, has lots of bioactive components which are also rich in the garlic. This study analyzed the bioactive components in garlic peel by Gas Chromatography-Mass Spectrometer (GC-MS) and Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). The antioxidant activities of garlic peel extract were investigated, in order to provide the oretical foundation and basis for the development and application of the garlic peel. The main contents are as follows:1. This study summaried the bioactive components in garlic, including extraction, isolation, analysis, biological activity, application, and other aspects, and put forward some viewpoints based on previous studies.2. The chemical compositions in garlic peel were detected and determined by Gas Chromatography-Mass Spectrometer for the first time, in order to contrast also detected and determined the chemical compositions of garlic. The results showed that the main compoents of garlic peel extracts by different methods for fatty acids, also contained a small amount of sulfide compounds and plant sterol, get the kinds of compounds in garlic peel extract which by supercritical carbon dioxide and soak extraction were more than that by ultrasonic extraction and soxhlet extraction, and the two methods to get the extracts contains sulfide compounds which contains in garlic extracts. They both have high medicinal functions and nutritional values.3. The contents of 14 elements (Na、Mg、Cu、P、K、Mn、Fe、Zn、Al、Cd、Sr、Si、Cr、 Pb) in garlic peel were detected and determined by Inductively Coupled Plasma-Atomic Emission Spectrometry for the first time, in order to contrast also detected and determined the elements of garlic. we also detected and determined the elements of the onion which is in the same department and genus. The six elements (Na、Mg、Sr、Fe、K、Si) content of garlic peel were higher than that of garlic, The results suggested that the high content of inorganic elements in flesh and peel were approximately the same, the same genus and department with a high content of inorganic elements in plant composition, were roughly the same, most of which are beneficial to human health, had high edible, nutrional and health function.4. In this study, the active extractions in garlic peel were extracted by using three methods: ultrasonic extraction, soxhlet extraction, and soak extraction. The antioxidant activities were evaluated by the scavenging ability to 1, 1-diphenyl-2-Picrylhydrazyl (DPPH), hydroxyl radical(-OH), superoxide anion(·O2-), and nitrite (NO2-).The results illustrated that the garlic peel extracts by different methods had the higher ability to scavenge four kinds of free radicals, and the higher the mass concentration was, the stronger the scavenging affected. It suggested that the garlic peel extracts had antioxidant activities, in which the active ingredients had thermal stability. Therefore, garlic peel extracts can be used as a potential natural antioxidant.