Analysis of Five-Extraction Technologies’ Environmental Impact on the Polyphenols Production from Moringa oleifera Leaves Using the Life Cycle Assessment Tool Based on ISO 14040

Abstract

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.