Principles of Green Food Processing (Including Lifecycle Assessment and Carbon Footprint)

G. J. THOMA, S. W. ELLSWORTH AND M. J. YAN

1.1 Introduction

The global food and agricultural sectors are facing numerous pressures, including the burgeoning global population, the expanding middle class and the increasing desire of more people to have high-quality, low-cost food. Numerous studies have shown that the main environmental hotspots within the food supply chain are associated with upstream activities (agricultural production, cultivation of crops and animal husbandry) and as a result have received the most attention from the consuming public, governmental organizations and non-governmental organizations (NGOs). These studies suggest that 70–90% of most environmental impacts in a full supply chain assessment can be attributed to the primary production phase; however, many of the same studies point to the food processing and manufacturing stage of the supply chain as being responsible for 10–20% of supply chain impact. Also, although it is tempting to focus only on those upstream activities where the majority of impact arises, sustainability cannot be achieved by focusing on those activities alone, but must also identify opportunities and implement improvements at later stages of the supply chain.

It is for that reason that this book is an especially strong addition to the literature for its focus on the food processing sector and the technologies and opportunities that exist for improvement of the environmental performance of food supply and improving food security.

The food manufacturing industry has traditionally held the role of ensuring food safety, regulatory compliance (for example, nutritional labeling), marketing and profitability. More recently, an additional layer of providing both information and documenting progress towards a sustainable food supply has been added. It should be clear that concerns over environmental sustainability of the food system will have secondary importance to the sector's traditional functions: unsafe, but environmentally friendly products will never be marketed. Hence the context of this chapter is to define the available operating space and useful techniques for understanding the role that environmental sustainability has in the food processing sector.

There is a consensus that the assessment of sustainability requires a holistic perspective of the system being evaluated. This includes the full supply chain, from cradle to grave, in addition to a full complement of environmental indicators. The cradle-to-grave perspective includes all activities necessary for the production of the item under study, extending back in the supply chain to the original extraction of resources. This means, for example, that coal mining and transport to the power plant to produce electricity for pumping or refrigeration are included. In addition, processes associated with consumption and end-of-life treatment are included. An example of the importance of including the full supply chain is in the evaluation of food packaging. One role of packaging is protection of the product, which reduces loss. Light weighting a package will make the package itself more sustainable, but if it leads to even a slight increase in food loss, the overall effect would very likely be a reduction in the overall sustainability of the system because of the relatively large impacts associated with the production of the food itself. By adopting a system perspective, tradeoffs between supply chain stages can be identified, which helps to avoid unintended consequences. In addition, a range of environmental categories should also be included in the overall assessment. Multiple categories allow the identification of potential tradeoffs between environmental impacts. For example, water use efficiency in a processing facility may be achieved at an additional energy cost and therefore the tradeoff of improved water use comes at the cost of an increased carbon footprint. This highlights the truism that "one size does not fit all." For example, in water-scarce regions a higher footprint for global warming may be a necessary and acceptable tradeoff.

1.2 Sustainability Assessment Tools

Sustainability is a complex concept with a deceptively simple definition: to meet the needs of current generations without compromising the ability of future generations to meet their needs. In general, sustainability is considered to have three pillars: social, economic and environmental. The complexity arises in attempting not only to balance environmental tradeoffs as mentioned above, but also to balance these tradeoffs with social and economic values that are deemed important. A major goal of sustainability assessment is therefore to identify the tradeoffs and tensions in the system so that fully informed decisions can be taken in an effort to maintain our collective ability to provide prosperity. Among the tools used for sustainability assessment are lifecycle assessment (LCA), lifecycle costing (LCC), social lifecycle assessment (SLCA), lifecycle sustainability assessment (LCSA), organizational lifecycle assessment (OLCA), environmental risk assessment (ERA) and, in the context of food safety, microbiological risk assessment (MRA). Some of these tools can be used in conjunction with each other or, depending on the needs of the assessment, may be used alone. An emerging paradigm in the context of systems is the so-called circular economy. In this paradigm, there is an explicit and conscious attempt to design products in a manner that makes the utilization of materials at the end of their intended life as raw materials for a subsequent use as streamlined and efficient as possible. Clearly, a fundamental principle of sustainability is resource use efficiency, and in the context of food processing this translates to minimizing energy and water use and food loss while simultaneously producing high-quality, nutritious and safe foods to enhance food security.

The most commonly used tool for system scale assessment of product systems is LCA, which is codified through a series of international standards, including general guidance in addition to specific guides for water footprint and carbon footprint. These standards are targeted at providing guidelines for products and services and specifically require a full lifecycle perspective for the reasons outlined above. The International Organization for Standardization (ISO) has not published guidelines at the organizational level; however, the UNEP/SETAC Life Cycle Initiative and World Resource Institute have published guidelines for adapting LCA to the organizational scale. LCC is a tool to permit the full cost of a product to be considered using the same system as used in LCA. The goal of LCC is to provide a full cost accounting of the production (including delivery and installation), operation and end-of-life costs (decommissioning and disposal) associated with a product. It may additionally include costs of externalities; for example, where environmental pollution costs that are borne by society can be quantified and verified, these externalities can also be included in the cost assessment. Integration of LCC and LCA remains relatively uncommon, yet is an important area because all enterprises must be both economically and environmentally viable. SLCA arose from efforts within corporate social responsibility initiatives to quantify the societal metrics associated with production and consumption. SLCA is the least developed methodology, but recently guidelines have been published and databases created that allow the assessment of social risks in supply chains. SLCA attempts to evaluate and quantify socially relevant indicators, including forced child labor, excessive work time, collective bargaining rights, health and safety and human rights. The European Commission, through the European Platform on Life Cycle Assessment, initiated an effort to extend the framework of LCA to incorporate LCC and SLCA to create LCSA. There remain clear challenges associated with collecting and maintaining up-to-date data in the social databases, and for this reason there are significantly fewer publications related to SLCA and LCSA than environmental LCA. For this reason, the remainder of this chapter will focus on environmental sustainability assessment. It should be noted that despite the growing popularity and utility of LCA, there are also some significant limitations to the methodology. For example, in evaluating agricultural production systems, LCA has limited capabilities with regard to the evaluation of ecosystem services, and also has only nascent capabilities for the inclusion of health effects associated with dietary choices or food-borne pathogens.

1.3 Standards and Regulations for Assessing Sustainability

ISO requires that the selection of impact categories shall reflect a comprehensive set of environmental issues related to the product system being studied, taking the goal and scope into consideration. In other words, impact categories should be relevant to the product system under study. However, a clear definition of the criteria that define "relevant" remains elusive, but this is beginning to change. In the past decade, Product Category Rules (PCRs) have been developed to set up standardized rules for products that serve the same functions, including choice of metrics used to estimate impacts. However, inconsistency in the choice of impact category has been found in a comparison of five different PCRs developed independently by different organizations. For example, The Sustainability Consortium (TSC) and the Korea Environmental Industry and Technology Institute (KEITI) share five impact categories (climate change, ozone depletion, photochemical ozone formation, acidification and eutrophication), while each requires the inclusion of another impact category: ionizing radiation by TSC and resource depletion by KEITI. To address the inconsistency and duplications of PCRs, The Product Category Rule Guidance was launched in 2013 to provide more specific guidance on developing PCRs. However, the selection of impact categories is still up to the individual PCR committee.

In addition to the ISO guidelines for LCA, additional efforts in several countries have led to the development of relative guidelines. Most notable among these are the Environmental Product Declaration (EPD), based on ISO 14025, in Sweden, the Publicly Available Standard (PAS) 205024 from the UK and the French standard BP X30-323-0, each of which provides additional guidance for the performance of LCA. Furthermore, at the level of the European Commission, through the Joint Research Council the ENVIFOOD, provision of guidance specific to food and agricultural products is available. The European Commission DG Environment, in an effort to enable companies to market sustainable products without the need to perform assessments specific to each country where they may wish to market the product, established the program Single Market for Green Products Initiative. They have published the Product Environmental Footprint (PEF) and Organizational Environmental Footprint (OEF), guidance documents for developing product and sector-specific category rules defining the way in which LCA can be conducted, with the purpose of communicating to consumers regarding the environmental impact of their purchases. PEF pilots were run between 2013 and 2016 to establish methods to ensure a common approach to measuring environmental performance. In doing so, the European Commission provided guidelines for the procedure for choosing impact categories in the pilot phase of conducting a PEF. It says that the identification of the most relevant impact categories shall be based on the normalized and weighted results of a screening study. However, pilot studies can also choose impact categories based on the communication purpose, which essentially links to the goal and target audience of the LCA.

1.3.1 The Role of Policy and Green Food Processing

In the USA, a 2010 study reported the estimated annual food waste at the retail and consumer level to be 638.7 kg per person. This food waste was valued to be $165.6 billion. Similarly, another study reported that 90 million tons of food waste was generated in the European Union in 2010.29 However, researchers looking at the methodology to calculate food waste highlighted the importance of data integrity and data collection. They suggested that government officials need to create policies that define and quantify what constitutes "food waste" due to variations among the definitions of different authors or agencies. Sustainability is widely viewed as consisting of three equal pillars: social, environment and economic. However, in the Handbook of Sustainability for the Food Sciences, Morawicki argues that the environment is the foundational support for both social and economic sustainability. In the global context, it is certainly true that without the full suite of functioning ecosystem services, society and the economy are threatened. Nonetheless, it is important that sustainability assessment considers the three pillars equally, acknowledges unavoidable tradeoffs and provides a lens for informed decision making – these two perspectives are shown in Figure 1.1. Environmental and social impacts are often external costs and are difficult to assess because there may not be an immediate and direct or obvious effect on profits. Similarly to the sulfur dioxide cap and trade that played a major role in mitigating acid rain, initiatives to implement a carbon emission tax or excessive waste dump taxes are actions by the government intended to put a price on these externalities. Another role of government policies is to foster communication between federal, state and local levels, guiding the discussion to improve sustainable practices. These policies have the potential not only to improve food safety of the industry, but also to improve sustainable practices among food plants. The impact of law and policy practices on the food industry will be further explored in a later chapter.

1.4 Introduction to LCA

In principle, LCA is simply an accounting of material and energy flows that result from each of the activities in the supply chain of a product or service. These flows are ultimately characterized and combined to provide a picture of the impact, across several environmental dimensions, of the system under study. LCA is a science-based, robust and standardized methodology for assessing the potential environmental impacts of products, services, or organizations. As described in ISO 14044, LCA consists of four stages, which will be outlined in the following subsections: Goal and Scope Definition; Life Cycle Inventory Collection; Life Cycle Impact Assessment; and Interpretation. Frequently in the process of performing an LCA it will be necessary to revise certain aspects based on new information, and thus the process becomes one of iterative refinement.

There are numerous reasons for performing an LCA, including the following: define opportunities for improvement through identifying activities that are major contributors to impacts (hotspots); develop performance benchmarks allowing the documentation of continual improvement; differentiate markets permitting the targeting of products towards consumers concerned about the impacts of products they purchase; design for environment, that is, considering the full lifecycle of a product at the initial development stages, enabling significant improvements to be made in overall lifecycle performance. With regard to marketing sustainable products, LCA is the basis for type III Environmental Product Declarations (EPDs) in which the environmental performance of a product can be communicated to consumers, following international standards. An example of design for environment would be the consideration of the biodegradability or recyclability of packaging in the early design that resulted in reductions in landfill burdens for the end-of-life phase.

Broadly, there exist two modeling paradigms for performing an LCA: attributional and consequential. Attributional LCA is an approach in which an average system is retrospectively evaluated and the emissions associated with the system are apportioned or allocated between multiple functions based on normative rules. Consequential LCA, on the other hand, does not consider the average system, but evaluates the anticipated change resulting from increased demand for an additional unit of product. Thus, the lifecycle inventories for the two systems are different, the first relying on averages and the second on data from the margin. Specifically, marginal processes are those processes anticipated to respond as a consequence of the additional demand. Attributional LCAs are typically used for identifying hotspots and benchmarking supply chain performance, whereas consequential LCAs are more relevant for decision support.