Cost-Engineering Analysis of Radio Frequency Plus Heat for In-Shell Egg Pasteurization

Salmonella spp. is a pathogenic microorganism linked to eggs and egg products. In-shell eggs are not required to be pasteurized in any country before they reach the consumer. The use of an emerging technology known as radio frequency has been successfully used to inactivate this pathogen inside in-shell eggs and claim pasteurization standards (5 - log reduction). The objective of this manuscript was to conduct the engineering cost of egg processing using a radio frequency pasteurizer and compare the processing cost to conventional thermal pasteurization for in-shell eggs. The ARS-patented radio frequency pasteurizer was used (40.68 MHz, 35 W) to pasteurize eggs in 24.5 min. The conventional thermal pasteurization (56.7 °C) required 60 min for the same level of inactivation. The techno-economic analysis (TEA) included information from stakeholders, egg processors and equipment manufacturers and was used together with energy balances and some key assumptions. Calculations for the engineering cost were made based on the required energy for each system, showing that the radio frequency required a third of the total cost of electricity to pasteurize eggs in a year compared with thermal, based on utilities costs in PA. Other utilities such as water and steam were also minor for radio frequency pasteurization. After two years of operation, the projected additional cost of processing is ~USD 0.19 per egg for the radio frequency system, compared with USD 0.22 per egg for conventional thermal treatment, largely due to volume-based amortization of capital costs and lower annual operating costs for the RF process. Radio frequency thus could be an option to pasteurize eggs in farms from PA and potentially in other states, using the system developed by our research team, while reducing energy consumption and increasing return on investment.