Enhancing the Shelf Life and Microbial Safety of Refrigerated Eggs Using Edible Coatings of Aloe Vera Gel Combined With Fennel and Lime Peel Essential Oils

Abstract

In order to investigate the effect of coating with aloe vera gel (100%), different levels of fennel and lime peel essential oil (0, 500, and 1000 ppm) on some qualitative and microbial characteristics of eggs at refrigerated temperature (5°C) during three storage periods (1, 15, and 30 days), an experiment was conducted as a factorial in a completely randomized design with three replications. During the storage period, the weight loss (%), Haugh unit, shell thickness, albumen and yolk pH, albumen foam production and total bacterial count were investigated. The results showed that the highest weight after 30 days of storage, the highest weight loss was observed in the control (4.81%), whereas all coated treatments showed significantly lower weight loss (3.35%–3.36%). The highest Haugh unit values were recorded in the treatments coated with aloe vera gel containing 1000 ppm fennel essential oil (65.74) and 1000 ppm lime peel essential oil (65.40), whereas the lowest value was observed in the control (54.17). The highest pH of egg white and yolk was observed in the control compared to other experimental treatments on days 15 and 30. Shell thickness was not affected by the experimental treatments (p > 0.05). At the end of the storage, the highest total microbial count was observed in the control (5.40 log CFU/g) and the lowest in the aloe vera + 1000 ppm fennel essential oil (4.16 log CFU/g) and aloe vera + 1000 ppm lime peel essential oil (4.17 log CFU/g) treatments. In general, it can be concluded that coating with aloe vera gel along with fennel and lime peel essential oil, particularly at 1000 ppm, can be used as an effective combination to reduce the microbial load and maintain the quality of the internal contents of eggs during the storage period.