A Life Cycle Assessment of Bread Production: A Cuban Case Study

Karel Dieguez Santana,Yannay Cacas-Ledon,Julio A.Loureiro Salabarria,Amaury Perez-Martinez,Luis E.Arteaga-Perez

1 Facultad Ciencias de la Vida,Universidad Estatal Amaz′onica,Paso Lateral km 2 1/2 V′?a Tena,Puyo,Pastaza,Ecuador

2 Department of Environmental Engineering,Environmental Science Faculty EULA-Chile Center,University of Concepci′on,Chile

3 Escuela Superior Polit′ecnica Agropecuaria de Manab′? Manuel F′elix L′opez,Calceta,10 de agosto#82 y Granda Centeno,Manab′?,Ecuador

4 Facultad Ciencias de la Tierra,Universidad Estatal Amaz′onica,Paso Lateral km 2 1/2 Via Tena,Puyo,Pastaza,Ecuador

5 Laboratory of Thermal and Catalytic Processes(LPTC),Wood Engineering Department,University of Bio-Bio,Concepcion,Chile

Keywords LCA Bread Cleaner production Inorganic respiration Cuban food industry

Abstract The bread production sector is a major food business for Cuban population,which has grown slightly in recent years. In an attempt to pro-vide a better understanding about the food industry sustainability in Cuba,this paper presents an environmental life cycle assessment to estimate the impact of bread production on the environment. This study evaluates from factory gate to output analysis of the processing factory,which includes processing each product and packaging. Two scenarios were compared to assess the effect of bread production on deteriorated technology, the potential benefits of incorporating new technology and clean production practices. The main results show that the Bread Production System-year 2011 (Scenario 1), presents the main impacts on humans and the ecosystem; where the bread production process shows the greatest impacts,with inorganic respiration and acidification/eutrophication being the most relevant categories of this environmental study. In the comparative study,the implementation of new technology in the bread production process allows for greater environmental compatibility,and reduces the overall effects related to the different impact categories by 44%,and damage categories by 47%. Finally,the environmental results were compared with other published studies on bread production in different countries,and various improvement measures are proposed to reduce the environmental impacts of the production process.

1 Introduction

Nowadays, ecological and environmental indicators are increasingly seen as necessary tools for sustainable development (Gong and Wall, 2001). There is increased awareness that the environmentally conscious consumer of the future will consider ecological and ethical criteria in selecting food products (Andersson et al.,1994). It is thus essential to evaluate the environmental impact and the resource use in food production for sustainable consumption. An ecological analysis should be one of the basis of food pro-duction structures and consumption. Minimal environmental impact combined with an efficient and natural use of resources must be important criteria for food product development as well as in the food system selection. (Mattsson and Soneson,2003) mention that to satisfy societal demand, an increasing food requirement has been observed. The food industry is one of the world’s largest industrial sectors. In parallel, the environ-mental impact related to this sector has also experienced an increasing attention. (Gonz′alez-Garc′?a et al., 2013; Iribarren et al., 2011), etc.With a production of 9 billion kg per year (Cho and Peterson, 2010). In 2011, 524000 tons of bread were produced in Cuba according to the Statistics National Bureau (Oficina Nacional de Estad′?sticas, in Spanish)(ONE, 2011). In Villa Clara, the Provincial Food Production Company has 134 production units distributed among 13 municipalities. Within this small industry, the “Pinto” Bakery, located in the center of the province capital, shows the highest production volumes. It has a continuous working system, solid waste generation,gaseous emissions from the cooking process with fossil fuel(diesel)in a very populated area,and liquid wastes with a high proportion of solids,fats,and organic load,which become a source of greater environmental impact.The impacts of waste generated by industry are varied,such as the same affecting: humans,water(all together flora,fauna and landscape units indirectly),air,land,and soil(Di′eguez-Santana et al.,2013).

One of the most widely accepted international methods to quantify the environmental impacts of food products is Life Cycle Assessment (LCA) (Roy et al., 2009). This standardized and holistic methodology allows identifying the environmental implications of a product life cycle, by evaluating potential environmental impacts along its entire production life cycle. (ISO,2006a). Life cycle assessment(LCA)is a tool for calculating environmental effects of a product,process,or activity throughout its life cycle or lifetime,which is known as a‘from cradle to grave’analysis(Casas-Led′on et al.,2015).

LCA method has been selected by several authors to conduct environmental assessments of a varied range of food products such as beer and soft drinks(Cordella et al.,2008),dairy products(Gonz′alez-Garc′?a et al.,2013),meat,and fish products (Driscoll et al.,2015; Huerta et al.,2016), fruit,and vegetables processing (Andersson et al.,1998;M¨uller et al.,2015),and food products such as basic carbohydrate foods(Dolci et al.,2016;Fusi et al.,2015).

Although bread production has already been the subject of several LCA studies (Andersson and Ohlsson,1999; Bimpeh et al., 2006; Geerken et al., 2006; Kulak et al., 2015; Kulak et al, 2016), they generally focus on the production of cereal and other raw materials(Korsaeth et al.,2012),distribution chains(Gr¨onroos et al.,2006),or greenhouse gas emissions(Espinoza-Orias et al.,2011;Jensen and Arlbj?rn,2014;Notarnicola et al.,2015),without a more detailed analysis of the production process.

In the present work,a comparison between two different alternatives for the use of by-products and wastes of bread production in Cuba is made, by means of LCA and using the SimaPro 7.2 software. Therefore, in an attempt to provide a better understanding of the environmental consequences of this sector, this paper presents the life cycle impacts of Cuban manufactured bread as well as the related impacts on the environmental performance of the Cuban food industry. Moreover,detailed inventory data has been reported which can help the LCA community focus on the environmental impact quantification derived from bread, which is basic in the Cuban people diet.

2 Materials and methods

In the present study, the Eco-indicator 99 (EI99) methodology has been used in order to identify and quantify the aspects that have the greatest environmental impact,and also to evaluate environmental improvement opportunities of both aspects in “El Pinto” Bakery. It produces around 700 tons of bread per year out of the 33178 tons produced in the municipality of Santa Clara in 2013(ONE,2014),where people elaborate a great range of products,mainly for the tourists in Cayo Santa Maria hotels.

This paper is about the application of Cleaner and Sustainable Production principles, proposed by the National Environmental Strategy 2011-2015 (CITMA,2010), and regulated by the Law 81 on Environment Protection(CITMA,1997).

The Life Cycle Assessment methodology was applied in the study. This procedure consists of four interrelated stages: i.) Goal and scope definition, ii.) Life Cycle Inventory (LCI),iii.) Life Cycle Impact Assessment(LCIA),and iv.) Interpretation (ISO,2006a,2006b)

2.1 Goal and scope definition

The life cycle analysis is carried out using SimaPro7.2 software, which aims to determine the environmental impacts associated with bread production for both technological variants.

We begin from the assumption that environmental loads are assignable to the processes of obtaining raw materials,associated with the production of inputs(wheat flour,vegetable fat,sugar,salt,and dry yeast)which are included in the environmental analysis. Environmental loads related to auxiliary materials(consumption of water,cleaning products,packaging materials)are assigned to the production of each one.

In the case of energy loads, these are assigned to diesel consumption and electricity used in industry (for baking products). The generation of electricity is considered to be based on the Cuban energy matrix. Solid waste management loads assignable to the disposal of solid waste in a landfill, or recycling processes of the recoverable fractions in the Bread Production System-year 2013(Scenario 2),were considered as products to be avoided. We also assume that transporting inputs to the factory or transportation intended for distribution is not included.

The chosen functional unit(FU)was 202kg of bread,equivalent to a production lot of 2520 loaves of bread(80g soft bark)ready for consumption.

2.1.1 Description of the case study

Scenario 1: Bread production is mainly based on electricity and diesel technologies. The Bakery Equipments were acquired on a date before the year 2000,and were deteriorated due to overuse. It is a process that combines a steady-state operation with several discrete stages (mixing, forming, dilation and cooking). This process requires high-energy consumption due to some oversized equipment,an oven with great difficulties of insulation and the consequent escape of heat.

It generates a liquid waste volume (8m3), coming from sanitation processes and sanitary facilities. The pollutant load is variable and frequently includes spills during the production process of fats, detergents and chemicals as disinfectants and degreasers. Solid waste is generated from raw material packaging, office waste,and food waste from the process, which are directly taken to the municipal landfill. (See left section of Figure 1)

Scenario 2: It is very similar to the previous one in terms of equipment, same mixing procedure (spiral rod),forming machine,stove with temperature regulation and a rotating furnace using diesel power. The biggest differences are in the key equipment renewal for process optimization, adjustment of nominal capacities, and structured design of production flow. Energy-efficient equipment which results in low electricity consumption,cooking oven with greater energy efficiency, and well thermally insulated. Cleaner production and other modifications are incorporated in the auxiliary systems: restructuring the sewer system including the treatment prior to dumping water into the sewer system. The solid waste is reused or recycled, the organic matter content decreased by 60%for organic waste of animal feed(formerly collected after sanitation activities and mixed with solid waste before going to the sanitary landfill). Moreover, paper, paperboard, and hard plastic are recycled to join recycling chains in Villa Clara Materials Recovery Company,having a positive impact on the waste and process. Water consumption is reduced by 20%. In the case of wastewater treatment, filters for coarse solid retention, grease and sand traps were installed, which together with organic matter decline so that it can be reused. The implementation of cleaner practices by training workers and production assistants, decreases the contaminant load received by the B′elico River. (See right section of Figure 1).

Fig.1 Overview of the case studies. Scenari1 and Scenario2. For the production of 202 kg of bread(soft bark)52.97 kg of wheat flour,2.12 kg of vegetable oil,4.24 kg of sugar,1.06 kg of salt,and 0.53 kg dry yeast are respectively required.These raw material quantities are the same for both scenarios.

2.2 Life cycle inventory(LCI)

Most of the data corresponding to annual average values have been provided by the factory (2011-Scenario 1,2013-Scenario 2),and therefore,the results of mass balance with the highest quality. Other data were measured(paperboard, paper, plastic, etc.). The value of commodities, hygiene supplies and water consumption, is the same for both categories.

Wastewater: The liquid waste was collected and analyzed at the Applied Chemistry Study Center (CEQA,acronym in Spanish), “Marta Abreu” Central University in Las Villas. The methods used for water analysis,were based on Standard Methods for Water and Wastewater Examination. No 21. Edition, 2005 (APHA &AWWA,2005)

Gaseous emissions: Gaseous waste from the furnace outlet, which is released freely into the environment,is produced by combustion. It takes part in heat circulation and the bread cooking process. Emission values are estimated by the Environmental Protection Agency(EPA)(USEPA,2000)based on furnace carbon balance,composition and fuel consumption.

Solid waste: To determine the amount of garbage and analyze the physical composition, the Standard Test Method for Determination of the Composition of Unprocessed Municipal Solid Waste(ASTM,2008)was considered to perform the manual classification of residues in individual components during several weeks along the study period.

2.3 Life cycle impact assessment(LCIA).Impact assessment methodology

The impact evaluation stage was based on the standardized LCA methodology (ISO 14040,2006). For classification,characterization and weighting,Eco-indicator 99(H)2.05/Europe EI 99 H/A was selected. This belongs to the LCIA damage-oriented methodologies or endpoint methodologies. The eleven impact categories of this indicator were evaluated using weighting based on the hierarchist cultural perspective. These impact categories are grouped into three categories of damages: Human Health, Ecosystem Quality, and Resources (Contreras et al.,2009;Goedkoop and Spriensma,2001).

3 Results and discussion

3.1 Summary of inventory data per functional unit

Table 1 provides key information about analyzed systems. Auxiliary materials, water and cleaning products consumption, liquid, gaseous emissions and solid waste final disposal for both scenarios (1 and 2). Scenario2 shows the waste amount that is reused(recovery rate,Animal feeding and Recycling 100%)and the rest goes to the city landfill,mixed with other material in the garbage truck.

Liquid effluent generation with high organic content, large amounts of sludge, and solid waste represent a common problem for all food industries (UNEP,1995). It is recommended, as expressed by McComas and McKinley(2008), to reduce and eliminate waste at the source, or the implementation of integrated waste management systems that allow the environmental burdens reduction in the process.

Strategies to minimize waste production as proposed by Hyde,Smith,Smith,and Henningsson (2001), energy efficiency, water and raw material saving, increasing the reuse and recycling at the site, are some of the practices implemented in Scenario 2. This study shows a 20 percent reduction of water and 25 percent of chemicals used in the sanitation process,along with a use rate of over 95%of solid waste,when performing trainings or workshops with operators,technicians and administrative personnel,and cleaner production is implemented.The productive process organization, and the incorporation of a much more efficient technology,reports significant improvements in energy indicator,consequently,in the air emissions.

3.2 Evaluation of the impact

Fig. 2 shows the most significant adverse outcomes throughout their life cycle, for both bread production alternatives. The most affected impact categories are breathing inorganic and acidification/eutrophication. They are associated with particulate matter emissions, nitrogen oxides (NOx), sulfur dioxide (SO2), and sulfate /nitrate/phosphate as the main contributors respectively. Other impact categories with lower rates are climate change by gaseous emissions,land use for the production of raw material,production of disinfectants, and fuel consumption.

Scenario 2 shows significant improvements from an environmental point of view,reducing total impacts by approximately 44%. This result only reflects impacts related to the bread production process and raw material production, focusing specifically on the use of diesel and electricity production. The auxiliary processes (productions of inputs such as flour, sugar, yeast, oil, etc.) present the same environment contribution for the two alternatives under study, since the same quantities are used for the functional unit (202kg of bread) defined in the LCA.

It shows the significant reduction in environmental impacts associated with diesel and electricity saving in the process, as well as wastewater treatment and solid waste disposal as recyclable material shown in the life cycle inventory (Table 1-2). The high consumption diesel furnace of Scenario 1, given the deficiencies mentioned in section 2, has the main negative impacts on bread production, and according to other studies,carried out in Scandinavia (Andersson and Ohlsson, 1999; Gr¨onroos et al., 2006), the cooking process is the most energy consuming stage of the entire bread production process.

Table 1 Life cycle inventory-Main data for 202 kg of bread(FU).

Fig. 2 Comparison between the two scenarios in bread production. Method Eco-Indicator 99 (H)V2.04. Europe EI 99 H/H.Ponderation.

The diesel and electricity amounts used in bread production are reduced in Scenario 2 by 58% and 37%,respectively, which results in a reduction of the impact categories (Fossil fuels) of the production processes of these materials throughout the whole cycle of life. On the other hand,the high-efficiency furnace contributes to the reduction of CO2,SO2,NOx,and particulate material emitted into the atmosphere,the latter being the main precursor for the impact category on inorganic respiration, so the environmental load is smaller in Scenario 2. This coincides with that mentioned by Calder′on, Iglesias, Laca, Herrero, and D′?az (2010), in the ready meal products industry, life cycle evaluation applies the Eco-indicator 99 method and it turns out that the fossil fuel consumption, inorganic respiration and Eutrophication potential are the most affected impact categories.Sundkvist, Jansson, and Larsson(2001), report a similar result,but in this case the product distribution and the raw material transport are responsible for one-third of the impacts, while transport influence was not analyzed in our study.

Emissions directly generated by the cleaning process, such as N, P, and COD present in the water (emissions) effluents, contribute significantly to the Eutrophication/acidification Potential, which is reflected in the consequent decrease of these inputs, and treatment of pollutant loads in water of Scenario 2, as well as by the decrease of NOx,SOx,among other polluting gases.

It is important to add that, although the global warming category does not show significant impacts as described above, the impact decreases by approximately 50%in Scenario 2,and is of considerable importance due to the geographic location of the facility (downtown, high population). This impact is mainly caused by diesel combustion for bread cooking,and also by electricity consumption derived from the Cuban energy matrix,95.75%among crude oil,fuel in thermal power stations,engines,diesel,and other fossil fuels. This category is the most affected in Scenario 1,where fuel and electricity consumption are greater than 4%. This is consistent with other studies in the literature(Calder′on et al.,2010;Sundkvist et al.,2001)as one of the main measures to achieve sustainability, and for saving electricity during food production processes.

On the other hand, according to Kulak et al. (2015) the cooking process affects the ozone formation categories and their human toxicity due to emissions such as: nitrogen oxides, benzene derivatives, and polycyclic aromatic hydrocarbons from diesel and wood combustion. The baking of bread based on electric energy shows great environmental benefits,since it provides an energy mix based on renewable sources,something that in our case would not be important to analyze because the Cuban energy matrix,as mentioned above,depends almost entirely on fossil fuels.

3.3 Evaluation of the damage category

The impact analysis by damage category shows that the most marked detrimental impact is on Human Health,(See Figure 3). This is mainly caused by emissions of respiratory inorganic compounds,previously explained in section 3.2. In previous studies,the high incidence in the damage to human health and the inorganic com-pound category has been shown. Particulate matter (PM) is a major contributor of damage to human health (Fantke et al., 2015; Gronlund et al., 2015). The PM impact assessment has been developed by Hofstetter (1998), and employed in the EI99 in relation to damage to human health (Goedkoop and Spriensma, 2001), expressed in years of disability-adjusted life(DALYs)(WHO,2014)with effects such as cardiopulmonary disease and lung cancer(Notter,2015). The bread production segment demonstrated a significant impact in terms of respiratory diseases (higher than 54%for both scenarios). The PM2.5 were related to nitrogen oxide emissions, especially during the baking process, which are being emitted into the atmosphere of a highly populated area. Particles<2.5 mm,mainly due to combustion of Cuban diesel, large amounts of impurities and sulfur dioxide, derived from the electricity consumed.

Fig. 3 Damage categories of environmental profiles for the scenarios considered. Method Eco-Indicator 99 (H) V2.04.Europe EI 99 H/H.Ponderation.

The main factor in ecosystem quality degradation is related to the acidification and eutrophication that represented (63.3% Scenario 1) of this category, also promoting the use of cultivable soil to obtain raw materials causes 23%of the damages. This is caused by the use of the wheat production system and also because of sugar and other cultivated products remains.

Electricity and heat production contributed to environmental impacts(Fig.3),which mainly affect the minerals,Global Warming Potential(GWP),and Acidification Potential(AP)categories,as in the case of(Gonz′alez-Garc′?a et al., 2014), who attributed the fossil fuel dependence to the energy generation. Also, in terms of mineral resources, a large part of the total impact is related to the extraction of diverse resources necessary for the production process and also for auxiliary activities.

The effects on damage categories are proportional to the impact categories and these,in turn,release emissions (water, earth, and air) to the environment, hence reduction of pollutants released into the environment is reflected in the overall impacts,both impact categories,damage categories,which can be verified in(Fig.3)that shows the contribution per damage category. Scenario1 was the most relevant in relation to bread pro-duction,because when compared with Scenario 2,it is 109%more harmful for human health,58%for eco-system quality, and 25% for resources, respectively. Therefore, Scenario 2 presents the lowest impact on all categories of damages expressed in points(Pt).

3.4 Comparison of LCA results with other studies

As pointed out previously and shown on table 2, there are several works related to LCA in bread production.Many of these results differ. The differences depend mainly on the country in which the study was performed,data quality(the use of primary or secondary data),types,sources and ingredient composition,processing technologies employed, transport operations, co-products/ waste handling, among other criteria. Even when some of these elements are known through previous studies,it is not possible to determine the exact reasons for these differences.

The work mentioned in Table 2 has been carried out mainly in European countries except Narayanaswamy,Altham, Van Berkel, and McGregor (2004) conducted in Australia. Most of them have taken 1 kg of bread as functional unit. There is a tendency in these studies to analyze greenhouse gas emissions mainly, but there are also works such as (Korsaeth et al., 2012; Kulak et al., 2015) that examine and evaluate various impact cate-gories.

In the category of Human Health, Geerken et al. (2006) showed the photochemical oxidation and GWP de-crease in the Belgium bread production compared with the last 200 years,which is being strongly related to the use of cleaner energy sources, unlike brushwood and coal used for cooking, and raw material transport in the year 1800.

For its part, according to a study made by Kulak et al. (2016), the baking process contributes around 20 to 25% of human toxicity, so cereal crop yields and the use of organic waste brings positive impacts in these categories and the GWP. Jensen and Arlbj?rn (2014) mention the processing stage, which is the second CO2 emission hotspot, due to high energy use(electricity and natural gas)and adds that the recovery of solid waste is the best evaluated option,as in our study. Similarly,Espinoza-Orias et al. (2011)states that wholemeal bread packaged in plastic bags has the lowest carbon footprint,if it is preserved to environmental conditions, because toasting and refrigerated bread storage increases energy expenses and CO2 emissions.

The energy matrix of each country has a high incidence in the environmental impacts because according to Notarnicola et al. (2015). French baguette is the best among 21 different kinds of European bread studied,despite not being one of those that require the least use of energy in the cooking stage, this is due to an electricity mix based on nuclear power, although wheat production, which presents high yields in French farms,has a positive effect on sustainability among damages to ecosystems,(Korsaeth et al.,2012;Narayanaswamy et al., 2004) have significant results for eutrophication and terrestrial ecotoxicity impacts, but the main im-pacts occurred at the farm-gate,being the management of the farm one of the main keys to reduce the bread production environmental footprint. Likewise,Geerken et al.(2006),the acidification and eutrophication po-tential increase significantly due to the increased use of mineral and chemical fertilizer in the raw material production activities from agriculture today,for that reason(Gr¨onroos et al.,2006;Reinhardt et al.,2003),propose organic crops with the organic waste application in agricultural land as the best scenario. Organic fertilizer avoids the production of a certain amount of N, P, and K. Mineral based fer-tilizers are a sustainable alternative that diminishes the acidification /eutrophication potential effects and mineral resource consumption. These categories are affected in our study but this is mainly due to air and wa-ter emissions during the production process.

In addition,industrial processing was demonstrated to be preferable over local bakeries and domestic breadmaking(Andersson and Ohlsson,1999;Kulak et al.,2015;Reinhardt et al.,2003). The only study that differs is the one conducted by Sundkvist et al. (2001),because the distances for raw material transportation and fin-ished products,from the mainland to Gotland island,Sweden affect the process sustainability. While,the pro-duction processes and distribution chains centralization improve the efficiency and sustainability, these results support the centralized productive proposals,the improvements and productive increases to be achieved with-in Scenario 2.

4 Conclusions

In this investigation, a study was carried out on the LCA of two different alternatives for the use of by-products and wastes derived from bread production in Cuba. LCA by Eco-indicator 99 methodology was used to identify critical environmental aspects, and implement sustainable improvements in the way Cuba manufactures bread.The bread production process using both alternatives showed the greatest environmental impacts throughout its life cycle, where inorganic respiration and acidification / eutrophication categories have the most relevant impacts in the environmental study.

An analysis was performed by damage category for each of the scenarios considered. The results show that the most notable and detrimental impact is on Human Health. Bread processing in Scenario 1 seems to

be the most polluting in general, due to its high fuel and electricity consumption in particular, and polluting wastes. Additionally, it was determined that Scenario 2 shows a reduction of the overall impacts related to impact categories by 44%, and damage categories by 47%. The study compared the results with other published documents on bread making. Although various bread making processes use different technologies and raw materials to obtain the final products, environmental impacts such as greenhouse gas emissions, resource use,and human toxicity are common in different studies of this sector.

Table 2 Comparison with other LCA studies previously published.

Finally, it is recommended that the Cuban food industry be urged to develop similar investigations as well as the corresponding economic analysis. It is also necessary to carry out a study on the impact of raw materials at the farm stage,which in the case of our study(wheat flour)comes from non-local sources.