Effect of ultrasound treatments on bacterial quality of table eggs during refrigerator storage

Abstract

Ultrasound has used as a green technology to preserving food and food products, it destroys pathogenic microorganisms without side effect and preserving the organoleptic properties. So, an experiment was conducted to compare three periods of ultrasound treatment of table eggs, 1, 2, and 3 minutes, using a conventional ultrasound device, in terms of bacterial count during 0, 1, 2, 4, and 8 weeks of refrigerated storage. A total of 240 fresh table eggs (red-shell eggs) were collected randomly from a flock of 20,000 Lohmann laying hens at Al-Amir Commercial Project Farm in Al-Musayyab city, Iraq. The eggs were divided into 4 treatments (60 eggs/treatment); T1: control, T2: ultrasound for 1 min. T3: ultrasound for 2 min. and T4: ultrasound for 3 min.  The results of total bacterial count and total coliform count at Zero time on the shell surface of the T2 and T4 decreased immediately to less than 100 cfu/egg and were 37 X 101 and 33 X 101 cfu/egg of T2 compared with 43 X 102 and 38 X 102 cfu/egg of T1. As the storage period increased to 2, 4, and 8 weeks in the refrigerator, the total bacterial count and coliform count on the shell surface of the four treatments continued to gradually increase, but the highest counts were recorded in T1 (control)t treatment (control). Concluded that treating table eggs with ultrasound for 1 or 2 min. decreased bacterial count level of table eggs during storage in the refrigerator.