Yumurta Kabuğu Zarı Proteinleri ve Gam Arabik Kompleksinin Emülsiyon Stabilitesi Üzerine Etkisinin İncelenmesi

Abstract

Emulsifiers are surface-active agents promoting the formation and stabilization of emulsions. The formation mechanism of additives used as emulsifiers also plays an important role. The production method of emulsifiers should be inexpensive, easy and create a standard product. For this purpose, a great number of studies have been carried out based on the development of new emulsifiers by complex coacervation method. Complex coacervation is a method based on the formation of coacervates as a result of the electrostatic interaction between positively and negatively charged molecules. In the food industry, proteins are used as positively charged molecules and polysaccharides as negatively charged components. Biopolymer coacervates are often used to fabricate specific microstructures providing new functional properties to foods. In this thesis, the potential of the proteins isolated from the egg shell membrane in the formation of complex coacervates was investigated. Despite their nutritional and functional properties, eggshell membrane proteins are considered as waste causing both environmental pollution and potential income losses. Gum arabic, which is frequently used in emulsifier studies, was chosen as the polysaccharide in order to create coacervate. The aim of this study was to produce a new emulsifying agent by complex coacervation method using eggshell membrane proteins and gum arabic and to examine the emulsification properties of the produced coacervates. Firstly, the proteins were isolated from eggshell membrane. Then, isolated proteins and gum arabic were mixed at different ratios and pH to determine the optimum conditions for coaservation. According to the turbidity results, the maximum interaction was found at pH 3.75 and protein:gum arabic ratio of 1:1 (w:w). The morphology of the coacervates were examined by optical microscope and environmental scanning electron microscope. In order to determine the effect of coaservates on emulsion stability, oil in water emulsions were prepared with different coacervate concentrations and stored at 4 °C for nine days. The particle size distributions and serum separations of the emulsions were examined. According to the measurement results, while the average droplet diameter of the control group without coacervate was 2401 nm, the average droplet diameter of the emulsions prepared with coacervates varied between 462 - 982 nm depending on the coacervate concentration used. In addition, serum separation percentage values of emulsions prepared with coacervates were found to be smaller than the control group which was prepared without coacervate, and the physical appearance of the coaservate incorporated emulsions were better during the storage. As a result, the potential of eggshell membrane proteins and gum arabic complex as an emulsifier has been demonstrated.