New technologies to enhance quality and safety of table eggs: ultra-violet treatment and modified atmosphere packaging

Abstract

In the present study the effect of ultra-violet (UV) treatment alone and in combination with 100% CO 2 modified atmosphere packaging (MAP) was evaluated both on the survival of naturally occurring bacteria, as well as on quality parameters of table eggs during 28 days of storage at 21°C. Table eggs were collected from the conveyor belt after the UV module, and placed on carton trays. A representative number of carton trays were packed in a high barrier multilayer pouch filled with 100% CO 2 . All eggs were stored at 21°C and analysed at 0, 1, 7, 14, 21 and 28 days of storage. Eggs not treated with UV and not packed were also included. On the eggshells total colony count, total coliforms and faecal coliforms counts, as well as the detection of Salmonella spp. were investigated. Moreover, chemical-functional parameters such as weight loss, albumen pH and Haugh Unit (HU) were evaluated. The total colony count on UV treated table eggs was approximately 1 log 10 CFU/g lower than untreated eggs (2.27 vs 3.29 log 10 CFU/g). During storage, CO 2 packed eggs maintained the initial values of HU, whereas the albumen pH decreased up to 1.5-2 points in comparison to unpacked eggs. The UV treatment was effective in reducing the total colony count on the surface of table eggs. MAP showed a great potential in maintaining/enhance the technological properties of egg constituents (higher foam stability of the albumen for meringue preparation) without significantly impacting on the microbial load of table eggs.

Reduction of Eggshell Microbial Load of Table Eggs by Ultra-Violet Treatment

“…The total numbers of aerobic microorganisms, Enterobacteriaceae, Escherichia coli, and yeasts and molds on the eggshells were significantly (p<0.05) reduced after exposure to UV disinfection for 7 s. A decrease of 0.85 log 10 cfu/eggshell of the total number of aerobic microorganisms was registered in our study. Similar results were obtained by De Reu et al (2006) and Pasquali et al (2014), when the natural bacterial load on eggshell was reduced by 0.9 log 10 cfu/eggshell after 4.7 s of UV treatment, and by 1.04 log 10 cfu/eggshell after exposure to UV disinfection for 7 s, respectively.…”