The food processing industry is a continuously developing sector that uses innovative technologies to efficiently process food products. During processing, food industries generate substantial amounts of by-products in the form of waste materials. This food waste consists of organic matter rich in bioactive compounds, such as polyphenols, carotenoids, and flavonoids. Improper management of food waste can adversely affect both the environment and human health, leading to environmental pollution and the release of greenhouse gas emissions. Thus, proper food waste management has become an urgent global issue. The presence of bioactive compounds (mainly polyphenols, flavonoids, and anthocyanins, but also carotenoids, alkaloids, proteins, lipids, and carbohydrates) in food waste holds the potential to transform them into valuable resources. Several sectors, including food and energy, have recognized food waste as an innovative source. Recently, much emphasis has been placed on optimizing the extraction yield of such bioactive compounds through the utilization of environmentally friendly and sustainable methodologies and solvents. Pulsed electric field (PEF)-assisted extraction is an emerging technique that holds promise for the utilization of waste materials. PEF technology can efficiently optimize the extraction of valuable compounds within a shorter time while minimizing solvent and energy consumption. In this review, we provide a comprehensive overview of the current state of PEF technology and its implications for recovering bioactive compounds from food waste. The integration of innovative technologies like PEF in the food processing industry can play a crucial role in managing food waste sustainably, reducing environmental impact, and harnessing the full potential of bioactive compounds contained in these waste materials. The objective of this critical review is to provide an overview of the utilization of PEF pretreatment for food by-products and to conduct a comparative analysis with other extraction techniques.

The aim of this study was to evaluate the efficiency of successive extraction (using solvents of increasing polarity, namely hexane, ethyl acetate, acetone, ethanol, and water) of polyphenols from Cistus creticus L. The results were compared with the ones obtained from a single-solvent extraction (ethanol, water, and 50% ethanol: water). According to the results, each solvent used for extraction had a significant effect on the yield of extracted polyphenols and the antioxidant activity of the extracts. The highest extraction yield for successive extraction was achieved with ethanol (95.33 mg GAE/g), whereas a comparable amount could also be extracted with 50% ethanol: water mixture single-solvent extraction (96.51 mg GAE/g). The ethanolic and aqueous extracts had the highest antioxidant activity as indicated by their lowest IC₅₀ values in the DPPH assay, specifically 350.99 μg/mL for ethanolic extract of successive extraction and 341.18 μg/mL for 50% ethanol: water mixture of single-solvent extraction, followed by the extract produced using acetone. However, the acetone extract contained more flavonoids than the other two extracts up to 28.03 mg QE/g. The results obtained were in line with those for the single-solvent extraction. It is concluded that using a range of solvents in succession is a more efficient way of extracting higher amounts of antioxidant compounds with varying antioxidant activity.

Nowadays, more and more researchers engage in studies regarding the extraction of bioactive compounds from natural sources. To this end, plenty of studies have been published on this topic, with the interest in the field growing exponentially. One major aim of such studies is to maximize the extraction yield and, simultaneously, to use procedures that adhere to the principles of green chemistry, as much as possible. It was not until recently that pulsed electric field (PEF) technology has been put to good use to achieve this goal. This new technique exhibits many advantages, compared to other techniques, and they have successfully been reaped for the production of extracts with enhanced concentrations in bioactive compounds. In this advancing field of research, a good understanding of the existing literature is mandatory to develop more advanced concepts in the future. The aim of this review is to provide a thorough discussion of the most important applications of PEF for the enhancement of polyphenols extraction from fresh food products and by-products, as well as to discuss the current limitations and the prospects of the field.