This study assesses the gate-to-gate environmental impacts of food processing systems operating in Toba Samosir Regency using Life Cycle Assessment methodology. The systems in question are processing of tapioca, coffee, and tofu, with the functional units of 50 kg of tapioca starch, 1 kg of coffee powder, and 25 kg of tofu, respectively. The inventory data were collected directly from the producers in the form of both production records and interviews. The linked flows that describe the production process for each of the system are obtained as follow. In producing 50 kg of tapioca starch, 200 kg cassava root and 800 kg of water are required. This system generates 40 kg of cassava peel, 60 kg of pulp and discharges 850 kg of waste water. For starch drying 209 MJ of thermal energy is required in the form of heating fuel. In order to produce 1 kg of fine coffee, 4 kg of coffee cherry and 30 kg of water are required. This system generates 3 kg of cherry peel and pulp mixture as solid co-product and discharges 30 kg of waste water. For roasting and milling the coffee bean, 90 MJ of thermal energy is consumed from firewood and gasoline. In producing 25 kg of tofu, 11 kg of soybean, 0.2 kg of flour and 140 kg of water are required. This system generates 16 kg of wet pulp and discharges 89 kg of waste water. For milling, 250 MJ of thermal energy is consumed from gasoline and rice husk. Water is the most vulnerable environmental compartment since most of the waste water is being discharged into the stream with limited treatment. The environmental hotspots associated with these systems are eutrophication potential, global warming potential (climate change), acidification, and photochemical oxidation potential.
Opening up the black box: A systematic literature review of life cycle assessment in alternative food processing technologies
