Dairy Processing

Life Cycle Assessment of a milk protein fractionation process: Contribution of the production and the cleaning stages at unit process level

“…This study also points out the fact that the cleaning phase is responsible for about a third of the total environmental impact of the process and that the contribution of the unit processes to the overall environmental impact of the cleaning phase is clearly dominated by cleaning of the membranes (especially when taking into account that this impact would actually be much higher if data and characterisation factors for certain cleaning agents was available). To reduce the environmental burden of the membrane cleaning stages two major strategies could be applied: (1) the reutilisation of the process water from the reverse osmosis used for the concentration of the milk proteins as rinsing water or water for the preparation of cleaning solutions, in order to reduce water consumption [18,51]. This strategy requires supplementary equipment for treatment of the permeate produced by reverse osmosis thus generating an additional impact; and (2) the rationalisation of the membrane cleaning [38,40,52], i.e.…”

“…Reduction of the environmental impact of the entire fractionation process can furthermore be projected through improvement of the energy-efficiency of the existing equipment [18], for instance by incorporating a concentration step prior to final spray drying [54]; or use of alternative technologies, such as centrifugation to separate the αlactalbumin precipitate from the soluble β-lactoglobulin [53] Prior to anticipating alternative technologies a comprehensive evaluation of their suitability should be conducted. Moreover, use of more environmentally friendly refrigerants, regular maintenance [18], use of enzymatic cleaning agents, instead of complex cleaning solutions [19,54] or ozone [55] and optimisation of the CIP programs can substantially reduce the overall environmental impact of dairy (and other) manufacturing processes; several remarks and suggestions are made by Rabiller-Baudry and co-workers [38,[56][57][58] on CIP of UF polymeric spiral membranes during filtration of skimmed milk such as to reduce the temperature and to switch from alkaline cleaning solutions to special solutions used for ceramic MF membranes [56] in addition to the use of biodegradable detergents. However, the extent of application of the different strategies highly depends on the processing requirements of the particular (dairy) product and on the membrane material and cut-off.…”

“…The possible negative impact of the cleaning steps is much more intuitive. It has been stressed that cleaning and disinfection have an important contribution to the global environmental impact of the food and dairy manufacturing industry due, on one hand to the extensive use of freshwater, and on the other hand to that of acidic and alkaline cleaning agents and the concomitant generation of effluents [14][15][16][17][18]. Cleaning and disinfection, which are extensively automatised using efficient cleaning-in-place (CIP) systems, are certainly indispensable to ensure the faultless mode of operation of the equipment and the sanitary quality of the food products.…”

“…Then it becomes necessary to conduct studies on cleaning-inplace contribution to dairy production, and special attention should be paid to the contribution of cleaning at the level of unit operations. An inventory of the generated impacts of the cleaning at the level of the unit operations has never been detailed thus impeding development of systematic and far-reaching improvement and optimisation measures for the cleaning stages and the management of entire food plants [18].…”