The current study evaluates the Pulsed Electric Field (PEF) technique for the extraction of polyphenols from the plants Rosa canina, Calendulaofficinalis and Castanea sativa. These plants are traditionally used both for the preparation of therapeutic decoctions and the aromatization of beverages (alcoholic or not). Pulses of 10 μs duration were used to apply electric field intensities ranging from 1.2 to 2.0 kV cm−1. The period of the phenomenon was set to 1 ms, with a total extraction time of 20 min. The total polyphenol content as well as the identified polyphenolic compounds of the extracts were determined for monitoring and evaluation. To estimate the PEF effect, control extracts were prepared using the same process as PEF extracts but without the application of electric field. For all the three plant materials studied, the PEF technique appeared to be successful in increasing polyphenols extraction. The application of a moderate to high electric field, up to 1.4 kV cm−1, resulted in increased total and individual polyphenols recovery, reaching 63.79% and 84%, respectively, in the case of Rosa canina fruits.

The present study examines, compares, and documents the environmental impact of five extraction techniques through Life Cycle Assessment (LCA). The material used was Moringa oleifera freeze-dried leaves and the assessment was based on their polyphenol content Three out of the five examined techniques are referred to in the literature as “green” techniques, namely Pulsed Electric Field (PEF), Microwave-Assisted Extraction (MAE), and Ultrasound-Assisted Extraction (UAE). The other two examined were conventional extraction techniques and, specifically, boiling water and maceration; the latter served as a control in this study. The analysis utilized special software (SimaPro ecoinvent) for the “cradle to gate” LCA, along with a sensitivity analysis of the model examining the variation in the environmental impact based on the origin of the source of electricity (renewable sources such as photovoltaic arcs), aiming to highlight the optimal technology choice. This LCA study's Functional Unit (FU) was one gram (g) of extracted total polyphenols (dry) produced by a case-specific number of extraction cycles for each technology under assessment (considering their technical efficiency depicted as polyphenols yields), measured by the Folin–Ciocalteu method and expressed as mg Gallic Acid Equivalents per g of dry Moringa oleifera leaves. The study outcome indicates that PEF and MAE deliver the best environmental scores. The main contributing parameters are the Moringa oleifera leaves and the amount and origin of electricity used to make 1 FU. These parameters are dominant in the categories of freshwater ecotoxicity, marine ecotoxicity, human carcinogenic toxicity, and human non-carcinogenic. The better performance of these two techniques is due to the more efficient extraction with reduced electricity consumption, which can become even more environmentally friendly if replaced with renewable sources such as photovoltaic arcs.

In Greece common marigold is one of the major medicinal plants widely used in cosmetics, perfumes and the pharmaceutical industry. A field experiment was conducted at Komotini, Greece, to compare the effect of organic and conventional fertilization combined with arbuscular mycorrhizal fungi inoculation on yield and floral qualitative characteristics of the common marigold during the 2015 growing season. The experiment was set up as a split plot design with three replicates, three main plots (fertilization treatments, inorganic, organic and untreated) and two sub-plots (addition/non-addition of commercial mycorrhiza of the genus Glomus spp.). Floral fresh and dry weight as well as total phenolic and flavonoid content of the dried flowers were recorded. Data analysis confirmed no significant correlation between fresh/dry floral yield, total phenolic and flavonoid content of the dried flowers and type of fertilization. The results also demonstrate a tendency of increase of the fresh or dry weight of the flowers when the commercial mycorrhiza is applied but it is not statistically significant.