Efficiency assessment of blanching and deep-freezing systems through data envelopment analysis

The aim of this paper is to define the blancher-freezer combination best fitting with the preservation treatment of a specific food. The proposed approach in decision making is based on the data envelopment analysis (DEA). Through the Cross efficiency evaluation, each decision making unit (DMU) is both self-evaluated and also evaluated via the other DMUs. Cross efficiency provides an efficiency ordering among all the DMUs, with a high discrimination power, avoiding potentially unrealistic weighting schemes. The efficiency, used for ranking and selecting the systems, is a function of the used resources (input values) and the resulting outcomes of each DMUs activity (output values). An interdisciplinary working group defined the proper set of input and output. As concern the blanching process, the selected input parameters are electric power consumption, steam consumption, water consumption, wastewaters, Biochemical Oxygen Demand and Peroxidase; the selected output parameters are residual Vitamin C and plant throughput. As concern the freezing process, the selected input parameters are electric power consumption, freezing capacity, dehydration and freezing time; the selected output parameter is the plant throughput. The proposed approach can be implemented to establish the ideal blancher/freezer selection also in the event of the need to include into selection other parameters or other food treatment systems.