Preservation of duck eggs through glycerol monolaurate nanoemulsion coating

Duck eggs have a short storage life. In this study, water-washed duck eggs and glycerol monolaurate (GML) coated duck eggs were stored at 25 °C for 70 days (away from light). The water-washed duck eggs started to lose weight from the 4th week. At the same time, Haugh unit and egg yolk index of the water-washed duck eggs started decreasing. The normal GML coating solution (NGML), the higher concentration GML diluent (HGML), and the lower concentration GML diluent (LGML) showed different preservation effects. Among them, NGML showed the strongest protection effect against spoilage of duck eggs. After 70-days storage, the weight loss rate of the NGML coated duck eggs was <6%, which was 4 times lower than that of the water-washed duck eggs; the Haugh unit and the surface morphology were also better than that of the water-washed duck eggs. Furthermore, the total colonies in NGML coated sample was >4 log CFU/g less than that was found in the water-washed samples (Control). The HGML and LGML coating agents were less effective but they might be suitable for the short storage of duck eggs due to the lower cost. Overall, this study provides a sound basis for the preparation and utilization of GML coating solution. The GML coating method is able to extend the shelf life of duck eggs by more than 6 weeks.