Olive oil is a core component of the Mediterranean diet known for its nutri@onal properties and health
benefits. Multi-phase decanter technology is a modern two-phase system producing, in addition to extra
virgin oil, a solid waste called ‘Pâté’ consisting of a wet fraction composed by pulp, skin, and vegetative water.
Pâté is enriched of bioactive molecules of great interest as bioprotectants against microbial pathogens. By
exploiting the tangential-flow membrane filtration (TFMF) eco-friendly technology, the vegetation water,
recovered from Pâté, was sequentially fractionated through a combination of microfiltration (MF),
ultrafiltration (UF) and nanofiltration (NF). NMR spectroscopy indicated the presence, in specific TFMF
fractions, of bioactive phenols such as tyrosol, hydroxytyrosol and oleuropein with a known antimicrobial
activity. High Performance Anion Exchange Chromatography with Pulsed Amperometric Detection (HPAECPAD)
profile showed the enrichment, of pectin-derived oligogalacturonides (OGs) a class of elicitors of
defense responses against microbial pathogens especially in UF concentrated fraction (CUF). CUF was able to
activate defense responses including the transient accumulation of cytosolic calcium and inductions of
defense genes in A. thaliana plants. CUF enriched in bioactive molecules, also induced resistance of A.
thaliana against Botrytis cinerea and Pectobacteriun carotovorum. This finding highlights the potential
valorization of olive mill by-products to be exploited as sustainable plant protectants against microbial
pathogens in alternative to chemical pesticides consistently with 'Green Deal' goals to halve the use of
chemical pesticides by 2030.