Just the tonic! Legume biorefining for alcohol has the potential to reduce Europe's protein deficit and mitigate climate change

Just the tonic! Legume biorefining for alcohol has the potential to reduce Europe's protein deficit and mitigate climate change 

Abstract;

Industrialised agriculture is heavily reliant upon synthetic nitrogen fertilisers and imported protein feeds, posing environmental and food security challenges. Increasing the cultivation of leguminous crops that biologically fix nitrogen and provide high protein feed and food could help to address these challenges. We report on the innovative use of an important leguminous crop, pea (Pisum sativum L.), as a source of starch for alcohol (gin) production, yielding protein-rich animal feed as a co-product. We undertook life cycle assessment (LCA) to compare the environmental footprint of 1 L of packaged gin produced from either 1.43 kg of wheat grain or 2.42 kg of peas via fermentation and distillation into neutral spirit. Allocated environmental footprints for peagin were smaller than for wheat-gin across 12 of 14 environmental impact categories considered. Global warming, resource depletion, human toxicity, acidification and terrestrial eutrophication footprints were, respectively, 12%, 15%, 15%, 48% and 68% smaller, but direct land occupation was 112% greater, for pea-gin versus wheat-gin. Expansion of LCA boundaries indicated that co-products arising from the production of 1 L of wheat- or pea-gin could substitute up to 0.33 or 0.66 kg soybean animal feed, respectively, mitigating considerable greenhouse gas emissions associated with land clearing, cultivation, processing and transport of such feed. For pea-gin, this mitigation effect exceeds emissions from gin production and packaging, so that each L of bottled pea gin avoids 2.2 kg CO2 eq. There is great potential to scale the use of legume starches in production of alcoholic beverages and biofuels, reducing dependence on Latin American soybean associated with deforestation and offering considerable global mitigation potential in terms of climate change and nutrient leakage — estimated at circa 439 Tg CO2 eq. and 8.45 Tg N eq. annually.

Authors:

Theophile Lienhardta,b , Kirsty Blackc,d,e,f , Sophie Sagetg , Marcela Porto Costaa , David Chadwicka , Robert M. Reesh , Michael Williamsg , Charles Spillaneb , Pietro M. Iannettae,f , Graeme Walker,d , David Stylesa,b

? a, School of Natural Sciences, Bangor University, Bangor LL57 2UW, Wales, UK: b, Plant and AgriBiosciences Centre, Ryan Institute, National University Ireland Galway, Galway, Ireland: c, Arbikie Distilling Ltd, Inverkeilor, Arbroath DD11 4UZ, Scotland, UK: d, Division of Food & Drink, Abertay University, Dundee DD1 1HG, UK: e, Ecological Sciences, The James Hutton Institute, Dundee DD2 5DA, Scotland, UK f Yeast Research Group, Abertay University, Dundee DD1 1HG, Scotland, UK: g, Department of Botany, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland: h, Scotland's Rural College, West Mains Road, Edinburgh EH9 3JG, Scotland, UK