Life cycle assessment of preserved plum production in Southern China

The fruit preservation industry in developing countries is growing rapidly and presents unique opportunities for promoting environmental sustainability. However, very few life cycle assessment studies have evaluated the environmental performances of current production technologies in developing countries. This study represents the first life cycle assessment to compare two common production lines of the preserved plum industry in Southern China and suggested strategies for improving their environmental performances. The first line, commonly adopted by medium-sized plants, included washing, osmotic treatment, blanching, superheated steam coupled with far-infrared radiation for drying, packaging and wastewater treatment stages. The second line, commonly utilized by small-sized plants, consisted of washing, osmotic treatment, drying by natural ventilation, packaging and wastewater treatment stages. The comparison suggested that the first production line resulted in higher fossil fuel depletion, ozone depletion, human health noncancer, respiratory and ecotoxicity impacts than the second production line. In contrast, the second production line resulted in higher photochemical formation, global warming, acidification, human health cancer and eutrophication impacts. Electricity and wastewater treatment, together, were the dominating contributors to most of the life cycle environmental impact categories. The sensitivity analyses suggested that the life cycle global warming impacts were most sensitive to electricity use, while the wastewater amount ranked as the most influential factor for the life cycle eutrophication impacts. In addition, the scenario analyses indicated that upgrading the activated sludge process to a membrane bioreactor process, for in-plant wastewater treatment, alone would increase life cycle fossil fuel depletion, photochemical formation, acidification and respiratory impacts. However, the combinational adoption of a membrane bioreactor process and electricity derived from wind or lignocellulosic biomass can significantly reduce life cycle environmental impacts of the plum preservation plants.