Department of Pharmacy, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy.
Department of Drug Sciences, University of Pavia, Via Taramelli 12, 27100 Pavia, Italy.
Molecules. 2022 Jun 20;27(12):3963. doi: 10.3390/molecules27123963.
Mill. essential oil is mainly used in the cosmetics and perfumery industry, but it also finds application in the food industry as a flavoring agent. The chemical composition of essential oils is affected by environment, soil, harvesting technique, storage condition, and extraction methods. Nowadays, the study and design of greener, more efficient, and sustainable extractive procedures is the main and strategic focus in the chemical research and development of botanical derivatives, especially as regards fragrances and essential oils. Several technologies are available, and the best method to use depends on the desired chemicals, but conventional extractive processes are often laborious and time-consuming, involve large amounts of solvents, and may cause the partial loss of volatiles, affecting the quality of the final product. In the last decade, microwave irradiation has been successfully applied to classical techniques, often improving the general extractive efficiency and extract quality. In the present paper, as a preliminary analytical screening approach, two microwave-mediated techniques, Solvent-Free Microwave Extraction (SFME) and Microwave Hydrodiffusion and Gravity (MHG), and two conventional procedures, Hydrodistillation (HD) and Steam Distillation (SD), were applied and compared for the extraction of volatile compounds from fresh petals to highlight differences and advantages of the selected procedure and of the obtained extracts useful in a cosmetic context as fragrances or active ingredients. The chemical composition of the extracts was investigated by GC-MS and GC-FID. Sixty-one components, distributed in the four techniques, were identified. SD and HD are dominated by oxygenated terpenes (59.01% and 50.06%, respectively), while MHG and SFME extracts are dominated by alcohols (61.67% and 46.81%, respectively). A relevant variability in the composition of the extracts relating to the extraction techniques used was observed. To point out the correlation between the process and composition of the obtained natural products, principal component analysis (PCA) of the data extracted from GC-FID was used. Taking into account a cosmetic application, SFME shows several advantages when compared with the other procedures. The extract (obtained in a significantly higher amount) contains a meaningful lower level of potential fragrance allergenic compounds and quite a double amount of benzyl alcohol and 2-phenyl ethanol that can also enhance the preservative action in personal care products.
迷迭香精油主要用于化妆品和香水行业，但也作为调味剂应用于食品工业。精油的化学成分受环境、土壤、收获技术、储存条件和提取方法的影响。如今，研究和设计更绿色、更高效、更可持续的提取程序是植物衍生产品化学研究和开发的主要战略重点，特别是涉及香水和精油。有几种技术可用，使用的最佳方法取决于所需的化学品，但传统的提取工艺通常费力且耗时，需要大量溶剂，并且可能导致挥发性物质的部分损失，从而影响最终产品的质量。在过去的十年中，微波辐射已成功应用于经典技术，通常可提高一般提取效率和提取质量。在本文中，作为初步分析筛选方法，应用了两种微波介导技术（无溶剂微波提取（SFME）和微波水扩散和重力（MHG））以及两种传统程序（水蒸气蒸馏（HD）和蒸汽蒸馏（SD）），用于从新鲜花瓣中提取挥发性化合物，以突出所选程序和获得的提取物在化妆品方面的差异和优势，例如香水或活性成分。通过 GC-MS 和 GC-FID 研究了提取物的化学成分。在四种技术中鉴定出 61 种成分。SD 和 HD 主要由含氧萜烯组成（分别为 59.01%和 50.06%），而 MHG 和 SFME 提取物主要由醇组成（分别为 61.67%和 46.81%）。观察到提取物的组成与所使用的提取技术之间存在显著的变化。为了指出所得天然产物的过程和组成之间的相关性，使用了 GC-FID 提取的数据的主成分分析（PCA）。考虑到化妆品的应用，SFME 与其他程序相比具有几个优势。该提取物（以更高的量获得）含有明显更低水平的潜在香味过敏原化合物，并且含有相当两倍的苯甲醇和 2-苯乙醇，这也可以增强个人护理产品的防腐作用。
