Formulation and application of cinnamon oil-chitosan emulsion coating to increase the internal quality and shelf life of shelled eggs.

Abstract

Eggs are one of the most versatile and nutritious foods and a good source of high- quality protein, vitamins, and minerals. However, as time passes, eggs' internal quality deteriorates due to evaporation of carbon dioxide and moisture through the eggshell pores. To increase the internal quality and shelf life of eggs, different types of coating materials such as oil, chitosan, and combination of variety of oils with chitosan have been applied to the surface of eggs. However, there is no information available on the combined effect of cinnamon oil (CO)- chitosan (CH) emulsion coating on chicken eggs. In this study, cinnamon oil- chitosan emulsions were prepared by dispersing cinnamon oil in Tween-80 emulsifier and water. The coating materials were applied to the entire surface of each egg with a sponge brush. CO-CH emulsions (CO: CH 3:97, 6:94, 9:91, 12:88 ratios), one 100% chitosan emulsion, and one uncoated control group were evaluated in this research study. Sixty eggs (10 eggs/treatment), of the total of 96 eggs, were evaluated weekly during five weeks of storage at room temperature (25?äù?é2?äù??C). The remaining 36 eggs were evaluated every three weeks throughout nine weeks of storage at 4?äù??C. Quality measurements including the Haugh unit (HU), weight loss percentage, yolk index, air cell height, and pH were done for all six treatments. Noncoated eggs' grade declined from AA to C after four weeks of storage at 25?äù?é2?äù??C while CO: CH 9:91 and 12:88 coated eggs' grade was turned to B after five weeks of storage at 25?äù?é2?äù??C. CO:CH 9:91 and 12: 88 emulsions coating significantly (p<0.05) retarded the yolk index and Haugh unit decline rate as well as the increase rate of weight loss percentage, pH value, and air cell height of eggs regardless of temperature. This study demonstrated that CO:CH coatings with ratios of 9:91 and 12:88 could preserve the internal quality of eggs and prolong their shelf life compared to the other treatments.