Sequential Pressurized Liquid Extraction of Food Matrices: Fractionation, Selectivity, and Scale‐Up

ABSTRACT

Pressurized liquid extraction (PLE), alternatively known as accelerated solvent extraction (ASE), facilitates the extraction of bioactive compounds from foods and food processing by‐products with less time and solvent usage compared to traditional extraction techniques. In sequential mode, the extraction process takes place in two or more sequential steps. Alterations in the solvent composition, temperature, or both during the sequential steps could assist in selecting a particular group of compounds and avoid overlap among fractions. Thus, the aim of the approach is the chemical separation of extractable compounds in different fractions. This review will focus on the design and evaluation of sequential PLE/ASE procedures with specific attention to process performance assessment. Two main variants of sequential procedures are considered: supercritical fluid extraction coupled with PLE/ASE, and multi‐step PLE/ASE with a solvent polarity gradient. Each factor such as temperature, pressure, solvent composition, and time influences the corresponding step of extraction; these factors are interrelated since each preceding step affects the material being processed in further steps. Analytical comparability and scalability aspects will be also discussed. Reported returns and payback periods are process‐specific and should not be generalized without recalculating plant scale, solvent recovery, equipment use, throughput, feedstock cost, and product value.