Ohe current Brazilian models for producing concentrated orange juice and sugarcane ethanol are not sustainable. The conclusion is part of Consuelo Fernandez Pereira's doctoral thesis, presented to the Faculty of Food Engineering (FEA) at Unicamp. According to the researcher, who based her analysis on a case study, the situation arises from the fact that both sectors are dependent on the use of fossil fuels and cause varying environmental impacts throughout their respective production chains. The research, guided by professor Enrique Ortega, was funded by the São Paulo State Research Support Foundation (Fapesp).

Research can be useful as a planning tool

In her study, Consuelo combined two methodologies to investigate the sustainability of agro-industrial products: Emergy Analysis (AE) and Life Cycle Assessment (LCA). The first measures the consumption of all energy used directly or indirectly to produce a given good or service. “In this calculation, we consider everything from solar energy, which does not have a financial cost, to the human work used throughout the production chain.”, explains the food engineer. The second evaluates all stages of a product's life cycle, from the acquisition of raw materials to the final disposal of waste. In other words, the methodology follows the product’s trajectory from cradle to grave. “By using AE and LCA together, we can obtain a more accurate diagnosis of the environmental performance of products and processes”, adds the thesis author.

Consuelo says she chose the two products for analysis because of what they represent for the Brazilian economy in general and for São Paulo in particular. In the 2005/2006 harvest, the country produced 14,4 million tons of concentrated and frozen orange juice, equivalent to 30% of world production. Of the total, 80% went abroad. As for ethanol, Brazil produced something like 15 billion liters of alcohol in the 2004/2005 harvest, 94% of which was destined for the domestic market. São Paulo alone accounted for 66% of this production. In the case of concentrated orange juice, Consuelo investigated the chain of both conventional and organic products. “Throughout the work, I visited orchards and industries and interviewed several technicians. This gave me a very broad view of the entire production system”, says the researcher.

Still in relation to orange juice, among the items considered in Consuelo's research were the agricultural system, the transportation of the orange to the industry, the transformation of the fruit into juice, transportation to Europe and transportation within European countries. The conclusion of the thesis author is that both conventional and organic products are not sustainable, mainly because they depend heavily on the use of fossil fuels. “This occurs at all stages of the chain, including in the agricultural phase, when fertilizers or irrigation systems are used”, she points out.

Although organic orange juice showed better performance, it also fell short of what was desired in terms of sustainability, according to the researcher. “In general, we can say that only 25% of the energy used in the production of conventional orange juice is renewable. In the case of organic juice, this rises to 30%. These are very low rates,” she says. Another data computed in the thesis refers to the loss of soil caused by the activity. According to Consuelo's calculations, for every liter of orange juice produced, 600 grams of soil are lost. Furthermore, 90 liters of water are consumed to produce the same liter of juice.

Ethanol – To analyze the performance of ethanol, Consuelo considered a level of harvest mechanization of around 15%, which is the average recorded in São Paulo. Although the product performs better than other biofuels, the researcher points out, its renewability rate is low, around 35%. “Although the use of bagasse as an energy source helps to minimize this impact, the sector still uses fossil fuel throughout its chain. In São Paulo, for example, alcohol is transported from plants to distribution bases and from there to gas stations using trucks. Depending on the distances travelled, the environmental impact is greater or lesser.”

Another relevant aspect raised by the thesis is related to carbon dioxide (CO2) emissions. Contrary to what some authors argue, Consuelo does not consider ethanol to be a CO2 mitigater. “The plant, in fact, absorbs much of this gas in the following cycle. It happens, however, that in each cycle emissions occur due to the use of fossil fuel: whether in the agricultural stage or in the ethanol production stage, since industrial inputs are used that generate CO2 during their production”. Another aspect that argues against alcohol in relation to environmental sustainability, recalls the food engineer, is soil depletion.

Sugarcane, according to her, accelerates soil exhaustion, which requires the application of increasingly larger amounts of fertilizers or a change in planting area. “It is for no other reason that many researchers and environmentalists are concerned about the contribution of this crop to deforestation in the Amazon, since it 'pushes' other agricultural activities to more distant regions”, highlights Consuelo. Asked whether it is possible to improve the orange juice and ethanol production models so that they become more sustainable, the researcher assesses that there is still room to improve both systems. In the case of both sectors, she considers the industrial stage to be quite efficient. “However, these activities still offer space for the use of renewable energy and more advanced ecological options. As for the agricultural phase, soil management can be improved to reduce the need for irrigation and the use of fertilizers,” she suggests.

When it comes to ethanol specifically, Consuelo advocates the creation of vegetation conservation areas to offset emissions from the production system. It would also be interesting to adopt new models of alcohol production and distribution, in order to include the construction of smaller plants to serve similarly small areas. “This way, the impact caused by emissions during the production and transportation of the product could be minimized”, he considers. According to Consuelo, the assessment of sustainability based on the combination of AE and LCA can be an important tool for planning more sustainable production models, as well as for the elaboration of public policies and even for the adoption of production systems. certification, an increasing requirement on the part of countries importing Brazilian products.