Extração por micro-ondas e suas aplicações

Abstract

Recently, the obtaining of bioactive compounds has become one of the main focuses of the food, pharmaceutical, and cosmetic industries. The extraction of these substances, traditionally carried out over the years, often had negative impacts on the environment and human health. In this context, modern techniques have emerged, offering greater sustainability and efficiency. This work aims to demonstrate the operating mechanism and the evolution of microwave-assisted extraction (MAE), considered a green technology, from the first uses of microwaves in laboratories to the present day. Through a bibliographic review based on scientific articles from databases such as Science Direct, Google Scholar, ACS Publications, and SciELO, a chronology of experiments carried out over time was elaborated, along with their applications in different matrices. In addition, this study demonstrates, through results obtained in several works, how microwaves promote faster, more efficient, and more sustainable extraction compared to conventional techniques. It also discusses the different versions of MAE, such as Focused Microwave-Assisted Soxhlet Extraction (FMASE), Solvent-Free Microwave Extraction (SFME), Vacuum Microwave Assisted Extraction (VMAE), and Nitrogen-Protected Microwave-Assisted Extraction (NPMAE), as well as hybrid techniques such as UMAE (Ultrasound-Microwave Assisted Extraction) and MAHD (Microwave-Assisted Hydrodistillation). The technological advancement of solvents enabled the emergence of deep eutectic solvents (DES) and ionic liquids (IL), which have been applied to improve MAE. Furthermore, the development of machine learning (ML) and artificial intelligence (AI) has made it possible to effectively determine the optimal point of operation, reducing costs, increasing yields, and allowing the prediction of process simulations under varying parameters. Based on the results obtained from microwave extraction and its applications in different matrices, it is observed that this technique offers shorter operation times with high efficiency. Consequently, the generation of solid waste and toxic vapors is reduced due to lower solvent consumption. Therefore, it is concluded that MAE has developed over the decades and has stood out as a technique that accelerates the extraction process with low environmental impact.