Analysis Of Eggshell

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1.0 Introduction
Egg remains an interesting and inexpensive protein source of the diet over two millennium years because of its nutritional and multifunctional properties. From the point of view of nutrition, egg is one of the complete food items, since it is rich in protein, amino acids, vitamin and most of mineral substances. Egg proteins have highest protein efficiency ratio, biological value and net protein utilization (Hoffman and Falvo, 2004). Egg can be used as a binding agent, a gelling agent, an emulsifier, a foaming agent and a coloring agent in food industry (Cook and Briggs, 1986; Watkins, 1995; Caner and Cansiz, 2007; Jaekel et al., 2008). There were 6.4 billion egg laying hens in the world and 1,182 billion eggs were produced …show more content…

Furthermore external defects of shell and internal qualities such as egg white, yolk, air cell depth and possible abnormalities are used in eggs grading (Egg-Grading Manual, 2000). The problems associated with egg storage are weight loss, internal quality deterioration and microbial contamination. Egg weight loss is due to removing of moisture and CO2 through porous eggshell. Eggshell is a mineral structure and it protects the eggs from mechanical damages, microbial contamination and dehydration up to a certain extent. However, since the eggshell is a porous structure, it can transfer moisture and CO2 (Stadelman, 1986). This is regulated by the cuticle which is an organic rich layer. Cuticle acts as a natural coating for the egg. It contains 85-90% of protein, 4% polysaccharides, 3% lipids, sulfur and some pigments. Those act as mechanical and microbial barrier for the egg. However, cuticle exists maximum for four days after laying. There is no regulation and no barrier after removing of cuticle (Alejandro et al., 2013; Samiullah and Roberts, …show more content…

Demineralization (DM), deproteinization (DP), decoloration and deacetyation are the basic steps of producing chitosan; this process is costly, thus limiting wider applications of chitosan. Simplification of chitosan production by elimination of the DM or DP step, or reduction of reaction time required for DM and DP (No et al., 2003) would considerably reduce production cost due to reduction in chemical usage, process time, and voluminous wastewater discharge. However, chitosan can be prepared in simple method for some uses, such as coating of eggs. Because that does not require a pure chitosan (No et al., 2005). There are two types of chitosan such as α-chitosan and β- chitosan based on origin (Kim et al., 2007). Chitosan is not dissolved in water or organic solvents, but it soluble in diluted organic acids such as acetic acid, lactic acid and forms viscous solutions (Kim et al., 2006; Chen and Zhao, 2012). Sealing characteristics can be vary with molecular weight of chitosan (Bhale et al., 2003) and solvent type (Kim et al.,

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