Recent advances in the extraction of bioactive compounds with subcritical water: A review

Background: Because of the important role of bioactive compounds in functional foods and health care, more and more attention has been paid to the active components extracted by green extraction methods. However, how to ensure the extraction yield and biological activity during the extraction process is an urgent problem to be solved. Subcritical water extraction (SWE) is a promising engineering method, which provides an environmentally friendly technology for extracting various bioactive compounds from natural products. Especially, under high temperature and high pressure, subcritical water can change the polarity and dielectric constant of solvents, thus contributing to a better extraction process, improving the mass transfer efficiency of the extracts and maintaining its biological activities, which has a high application prospect. Scope and approach: This review provided an update overview on the fundamental principles and bioactive compounds extraction with subcritical water. This will contribute to deepen the understanding of SWE and provide theoretical basis and reference value for further improving the application of subcritical water. Key founds and conclusions: It is expected that this green and efficient extraction technology will be increasingly applied in the extraction of more bioactive ingredients in the near future. In addition, future research should consider combining SWE with other physical extraction techniques to ensure the retention of the biological ingredients better. These active compounds with SWE have great potential in health care medicine and functional foods. Meanwhile, future researches should focus on consumer acceptability, safety, legal aspects, and commercial availability of health products.