Truitt Brothers has retained the Network for Business Innovation and Sustainability (NBIS) and their subcontractor the Institute for Environmental Research and Education (IERE) to perform a life cycle assessment study, in conformance with the ISO 14044 standard. The goal of this study is to provide a comprehensive assessment of the environmental impact of canning green beans by Truitt Brothers for use in marketing and customer support, while providing context for the major alternative preservation technique, freezing. The overwhelming majority of Truitt Brother’s product is produced for commercial, rather than home-based use.
The scope of the study is a comparison of the preservation of green beans, from the time it is delivered to the plant until it arrives at the wholesale customer. A hypothetical conservative assessment of freezing is used for comparison with the known canning process.
The study is a gate-to-customer study, ignoring the upstream production of the beans themselves, because it was assumed that the production of the beans was the same whether canned or frozen. While this is certainly true of beans delivered from the fields, frozen beans have more waste associated with them due to losses during storage. Agricultural production processes tend to dominate the life cycle impacts of food, so the one to three percent extra wastage in the frozen system may be significant in the context of canned versus frozen food. The environmental impacts of food preparation and consumption are ignored in this study, because it is assumed that they will be the same for the two preservation methods.
The reference flow for the study is a year’s production of the Truitt Brothers Cannery, while the functional unit is preserving a single 4 ounce serving, for one year. Two years is the minimum amount of time that canned foods are considered to retain acceptable quality. The Truitt Brothers “sell-by” date is three years. In contrast frozen green beans are known to lose quality fairly quickly, with a maximum freezer time of 296 days. This study does not provide a comparative assertion of the overall superiority of canning versus freezing beans as defined in ISO 14044, for three reasons: 1) As noted below, the Truitt Brothers represent a small fraction of the total amount of processed green beans in the country 2) The data on the freezer impacts are hypothetical in nature 3) The study does not represent a full cradle to grave assessment.
The audience is primarily Truitt Brothers’ commercial customers, although the results will be shared with others, such as the Food Alliance and other non-governmental organizations (NGO’s) as well as other interested parties.
The environmental impacts are calculated using the US EPA’s TRACI methodology.