Life cycle assessment from early development stages: the case of gelatin extracted from tilapia residues

Abstract

The skin and other residues that arise from the production of tilapia fillets can be used as feedstock for gelatin extraction. To derive maximum benefit from these residues, two gelatin extraction processes were developed at the laboratory scale: process A that used Nile tilapia skin as feedstock and process B that used residues from the extraction of mechanically separated tilapia meat. This study initially evaluates the environmental impact of these two extraction processes at the laboratory stage to determine the relative impacts of each one. Scenario analysis is performed for the choices available at the laboratory stage, regarding the use of reagents. Furthermore, the laboratory process with the lowest environmental impacts is scaled to a pilot plant and its performance evaluated. The ReCiPe midpoint method was applied to evaluate the categories of climate change, ozone depletion, terrestrial acidification, freshwater eutrophication, marine eutrophication, photochemical oxidant formation, particulate matter formation, ionizing radiation, water depletion, metal depletion, and fossil depletion. The categories of freshwater ecotoxicity and carcinogenic and non-carcinogenic human toxicity were assessed using the USEtox model. Results show that the production of gelatin from process A was less environmentally burdened than that from process B, among all impact categories. The scenario analysis shows that the replacement of some reagents reduced the environmental burdens of gelatin in both processes, but process A still performed better than process B did. The up scaling of process A revealed that impacts mainly resulted from the energy used for drying the gelatin solution and the use of resin and activated carbon for deionization and deodorization of the gelatin. This study argues that despite the challenges of applying life cycle assessment from early research stages, results from these efforts allow a search for alternatives at an early research stage that are both viable at the pilot stage, in terms of equipment requirements, and would lead to lower environmental impacts. Without such analyses, new developments may be a scientific breakthrough but will not evolve from the laboratory to the industrial scale. The main contribution of this work is the determination of an environmentally sound technological route for gelatin obtained from tilapia residues. According to the performed analysis, the production of gelatin from tilapia residues at the pilot scale should use skin as a raw material. A research agenda is presented to improve further the sustainability of process A.