Egg quality and food safety of table eggs

Abstract

This study is an update of data presented previously (Roberts & Chousalkar, 2012) from a study which investigated egg quality at different stages of lay. Although eggs produced in Australia are considered medium to low risk for food borne illness, the egg industry in Australia is periodically implicated in cases of food poisoning. Egg shell defects may potentiate the movement of bacteria into the egg. Two egg shell characteristics were targeted: the extent of cuticle cover and the incidence of translucency. Eggs were collected from commercial caged layer flocks at different stages of lay: early (<25-40 wks), mid (40-55 wks), late (55-65 wks) and very late (>65 wks). Eggs were candled and scored for translucency. Cuticle cover was estimated using MST cuticle stain and a Konica Minolta hand-held spectrophotometer (L*a*b* colour scale). Traditional measures of egg quality were determined using specialised equipment (TSS, U.K.) Shell ultrastructural features were scored following plasma ashing of shell samples and viewing under a benchtop scanning electron microscope.