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New STAR-ProBio publication “Life cycle assessment of autochthonous varieties of wheat and artisanal bread production in Galicia, Spain”

Câmara Salim, I.; Almeida-García, F.; González-García, S.; Romero-Rodríguez, A.; Ruíz-Nogueiras, B.; Pereira-Lorenzo, S.; Feijoo, G.; and Moreira, M.T.

Abstract

For millennia, bread and wheat have been one of the most important sources of nutrients in many civilizations. Today, mechanization and evolution in agriculture and food processing have intensified yields and modified the biological and nutritional aspects of multiple crops and foods. The Galician bread is a reference value of food heritage in Spain, which is made from common wheat grain and is a mixture of indigenous Galician wheat and conventional Spanish wheat. In the pursuit of product excellence, it is interesting to identify the environmental profile as support criteria in decision-making, not only to analyse product environmental sustainability, but also as a marketing element to improve consumer awareness.

The paper has a twofold perspective to analyse the environmental burdens of wheat cultivation and the bread sector, using life cycle assessment approach: 1) the comparison of the different types of agricultural systems, i.e. the cultivation of Galician wheat following a strategy of monoculture and crop rotation, certified Galician seed production and its comparison with conventional wheat cultivation and 2) the environmental profile of Galician bread. The functional units chosen were 1 kg of wheat grain transported to the milling facility and 1 kg of Galician bread.

The results show that wheat cultivation presents the main environmental impacts of bread production, mainly due to the use of agrochemicals and field emissions. The best cultivation scenario corresponds to a crop rotation system, since chemical fertilisation is not applied. In comparative terms with many staple foods produced in Europe, Galician bread has a low environmental impact. The overall environmental results of bread production draw attention to the dependence of bread and flour manufacturers on the agricultural sector, highlighting the need to share responsibilities across the supply chain. In addition, this study contributes to the stakeholder debate on environmental impacts related to food heritage.

URL: http://www.sciencedirect.com/science/article/pii/S0048969720302308

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Exploring the production of bio-energy from wood biomass. Italian case study.

Sara González-García, Jacopo Bacenetti

The concerns related to the environmental impact related to energy production from fossil fuel are increasing. In this context, the substitution of fossil fuel based energy by bio-energy can be an effective solution. In this study, the production of electricity and heat in Italy in a combined heat and power plant (CHP) based on an Organic Rankine Cycle (ORC) turbine from wood based biomass both from forest and agricultural activities has been analysed considering four potential alternative scenarios to the current energy status: biomass from very short rotation forestry (VSRF) poplar and willow stands as well as residues from natural forests and from traditional poplar plantations. The evaluation has been performed by applying Life Cycle Assessment (LCA) method and an attributional cradle-to-gate approach has been followed. The expected savings of greenhouse gases emission and fossil fuels demand have been quantified, as well as derived emissions of toxic pollutants and substances responsible for acidification, eutrophication and photochemical oxidant formation. The results have been also compared with the conventional Italian scenario considering the current Italian electricity profile and heat production from natural gas. Among the different scenarios, due to the lower transport distance, the use of biomass from traditional poplar plantation residues shows the lowest impact. The biomass combustion emissions are the main hotspot for several evaluated impact categories (e.g., particulate matter formation, human toxicity). In fact, when the produced bio-energy is compared to the reference system (i.e., electricity produced under the Italian electric profile) the results do not favor bio-energy systems. The results reported in this study support the idea that forest residues would be an interesting and potential feedstock for bio-energy purposes although further research is required specifically with the aim of optimizing biomass supply distances.

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Estimating the environmental impacts of a brewery waste–based biorefinery: Bio-ethanol and xylooligosaccharides joint production case study

Sara González-García, Pablo Comendador Morales, Beatriz Gullón

In the food industry, the brewing sector holds a strategic economic position since beer is the most consumed alcoholic beverage in the world. Brewing process involves the production of a large amount of lignocellulosic residues such as barley straw from cereal cultivation and brewer’s spent grains. This study was aimed at developing a full-scale biorefinery system for generating bio-ethanol and xylooligosaccharides (XOS) considering the mentioned residues as feedstock. Life Cycle Assessment (LCA) methodology was used to investigate the environmental consequences of the biorefinery system paying special attention into mass and energy balances in each production section to gather representative inventory data. Biorefinery system was divided in five areas: i) reconditioning and storage, ii) autohydrolysis pretreatment, iii) XOS purification, iv) fermentation and v) bioethanol purification. LCA results identified two environmental hotspots all over the whole biorefinery chain: the production of steam required to achieve the large autohydrolysis temperature (responsible for contributions higher than 50% in categories such as acidification and global warming potential) and the production of enzymes required in the simultaneous saccharification and fermentation (> 95% of contributions to terrestrial and marine aquatic ecotoxicity potentials). Since enzymes production involves high energy intensive background processes, the most straightforward improvement challenge should be focused on the production of steam. An alternative biorefinery scenario using wood chips as fuel source to produce heating requirements instead of the conventional natural gas was environmentally evaluated reporting improvements ranging from 44% to 72% in the categories directly affected by this hotspot.

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