Using acorns in innovative foods for human consumption could contribute to preserving Portuguese agroforestry systems and the environment

Modern food systems require diversification across both production and consumption to achieve better health for planet and people. We study the environmental impact associated with the use of acorns as ingredients for direct human consumption – as opposed to animal feed – from an agroforestry (montado) system in Portugal, using different allocation approaches for land occupation and carbon sequestration. We show that the four acorn-based products assessed - burger patties, pâté, flour and fermented acorns - are associated with carbon savings when above- and below-ground carbon sequestration is accounted for, with (negative) carbon footprints as low as -88.1 kg CO 2 equivalents per kg of flour. Whilst meat-substituting acorn products are associated with significantly lower environmental burdens than their conventional alternatives, fermented acorns and acorn flour, which replace plant-based foods, are associated with significantly higher burdens across other impact categories, notably marine eutrophication 28 to 267 times higher for fermented acorns than olives. Higher burdens across these categories largely reflect high nitrogen input from animal manure deposition, which exceeds the critical load range for N for this type of ecosystem and should be reduced. Production of novel food products from acorns could support maintenance or expansion of montado systems, enhancing diversity and carbon storage in the landscape whilst displacing more environmentally damaging food products.