Optimization of Extraction of Bioactive Compounds: Influence of Parameters on the Efficiency of the Microwave-Assisted Technique

The use of bioactive compounds (BACs) in various industrial sectors has grown considerably due to their health-beneficial properties. BACs can be extracted from different plant matrices, such as plants, fruits and their by-products. Various extraction techniques have been developed to maximize efficiency and reduce costs. Microwave-assisted extraction (MAE) is presented as a more ecological and cost-effective alternative. MAE is based on solvent extraction and the heating capacity of microwaves, where electromagnetic energy penetrates the plant matrix and interacts with polar molecules, generating heat and pressure that accelerates the extraction and solubilization of the compounds. However, high temperatures, high extraction times and high pressures could lead to the degradation of specific BACs. For this reason, the optimization of MAE operational parameters such as pressure, temperature, microwave power, exposure time, as well as matrix and solvent characteristics is essential to obtain a maximized extraction yield. In this sense, the application of mathematical models such as the implementation of the response surface methodology (RSM) and the central circumscribed composite design (CCCD) is necessary to describe the combination of MAE operational parameters to maximize the obtaining of BACs, allowing to predict with greater accuracy the experimental results. This summary highlights the recent advances in the understanding of MAE for BACs extraction, providing a solid basis to optimize extraction methods and maximize the use of BACs in diverse applications. A comprehensive literature review was conducted, covering studies from last five years using electronic databases including PubMed, ScienceDirect, Web of Science, and Scopus searching for peer-reviewed articles using keywords such as "mirowave-assisted extraction", "bioactive compounds", and "extraction optimization".