Effects of Propolis Extract Coating on Shelf Life and Quality Parameters of Eggs Obtained from Free-Range Hens

Abstract

The study was carried out to demonstrate the effects of the use of water-extracted propolis (PE) as a coating material on shelf life, storage temperature, time, and egg quality parameters obtained from free-range laying hens. The idea of coating an egg with a product to preserve its freshness for a longer time has been the subject of research by researchers. For this purpose, there are studies using samples of propolis extracted using different alcohols. In this study, the effects of coating eggs obtained from free-range reared chickens with water extracted PE and keeping them in different storage conditions on the internal and external quality parameters of the eggs were investigated. For this purpose, 80 eggs were collected from 64-week-old Lohmann brown layers. Egg samples were divided into groups of 8 treatments [2 storage times (10 and 20 days) x 2 storage temperatures (4 degrees C and 22 degrees C) x propolis coating on the shell (coated/uncoated)] and arranged to contain 10 eggs per treatment. In the study, it was seen that PE caused positive effects on the shelf life and internal quality characteristics of eggs stored at room and refrigerator temperature, as it covers the pores on the shell. As a result of coating with propolis extract, specific gravity and egg yolk index values increased (P <0.05). In addition, the number of mesophilic bacteria has decreased. Due to these positive effects, propolis can be considered as a natural alternative product that can be used for eggshell coating. It was determined at the end of the research that coating with the water-derived extract of propolis, a by-product of beekeeping activities, might have positive effects on long-term storage.