Quality of radio frequency pasteurized shell eggs during extended storage under normal and moderate abuse conditions

Effect of Radio Frequency Energy for Intervention Processing on the Quality of Intact Eggs

During conventional pasteurization, eggs are submerged for 60 min at 56.7 °C, a lengthy and costly process that affects egg quality. Radio frequency (RF), a means to pasteurize eggs without affecting quality, is a novel option based on fast volumetric heating; however, there is scarce information about the quality of such treated food. This research consisted in a comprehensive quality study on eggs treated with RF. The RF system was operated at 40.68 MHz, 40 W and 16 W (8 min total), and 42 rpm. The quality assessment included the determination of Haugh unit, yolk index, compression strength, albumen turbidity, albumen and yolk pH, and yolk color. Additional analyses were conducted to quantify the mineral composition of the eggshell (40.68 MHz, 40 W, 42 rpm, 5.5, 8.5, and 10 min); these samples were observed by SEM. The results showed that RF did not significantly (p > 0.05) change any quality parameters. The mineral composition remained constant in processed eggs. The SEM images of RF-treated eggs showed some smooth spots; however, these areas could exist due to the high variability of the eggshells. RF is an option to process intact eggs, maintaining their fresh quality and keeping the integrity of the eggshell to ensure the food safety of the internal egg components.

A review on egg pasteurization and disinfection: Traditional and novel processing technologies

Salmonella Enteritidis is a pathogen related to many foodborne outbreaks involving eggs and egg products. Regulations about whether eggs should be pasteurized are very different and inconsistent worldwide. In the United States, eggs are not required to be pasteurized. Hence, less than 3% of the eggs in the country are pasteurized. The standard pasteurization method (57°C, 57.5 min) uses a long thermal process that increases the cost of the product and affects its quality. Foodborne outbreaks can be reduced if eggs are properly pasteurized to inactivate Salmonella spp. However, the technology to pasteurize eggs needs to offer a faster and more reliable method that can be scaled up to industry settings at a low cost and without affecting product quality. Several novel technologies have been tested for eggshell disinfection and egg pasteurization. Some thermal technologies have been evaluated for the pasteurization of eggs. Microwave has limited penetration depth and is a technical challenge for egg pasteurization. However, radio frequency can penetrate eggshells effectively to inactivate Salmonella, considerably reduce processing time, and maintain the quality of the product. Nonthermal technologies such as ultraviolet, pulsed light, cold plasma, ozone, pressure carbon dioxide, electrolyzed water, and natural antimicrobials have been explored for surface cleaning of the intact egg as alternatives without affecting the internal quality. This review presents some of these novel technologies and the current challenges. It discusses the possible combination of factors to achieve the egg's internal pasteurization and the eggshell's disinfection without affecting the quality at a low cost for the consumer.