[Batcat]

Hello all, i have just joined your forum, and i am looking for an answer to something.

I am doing a Technology project at my school (i am from denmark by the way, soo my english isn't that good either) and we are trying to make a product that can eliminate salmonella from eggs (if you could then dont come with statistics about how little a problem salmonella is). and we have all sorts of ideas for example. pouring boiling water over them (not a lot), microwaving them for a short period of time, and others.

the one i am focusing on is one i found myself, if we were to make an artificial eggshell and therefore be able to make a Pasteurization of the eggs before we sell them. what would that take.

I have read up on what eggshell mainly consists of, but i am still not sure.

soo with that in mind.

Can i make an artificial eggshell, and if soo. What should i use and how do i make it?

I would love it if you could answer this, since this is going for my exam in technology.

PS. you can also email me the answer at

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0109FT@edu.esh.dk which is my school mail

[Alpha-Omega]

Here is a starting point:

Calcium carbonate, CaCO3, is found in nature giving hardness and strength to things such as seashells,
rocks, and eggshells. As hard as this substance is, it will react readily with hydrochloric acid to yield
carbon dioxide gas (and two other products). In this experiment students will design an experiment by
reacting eggshells with 3 M HCl to compare the calcium carbonate composition of white (chicken)
eggshells to brown eggshells.

A good quality eggshell will contain, on average, 2.2 grams of calcium in the form of calcium
carbonate. Approximately 94% of a dry eggshell is calcium carbonate and has a typical mass of 5.5
grams,1 although these values can differ depending on sources. Amounts as low as 78% have been
published.

The remaining mass is composed largely of phosphorus and magnesium, and trace
amounts of sodium, potassium, zinc, manganese, iron, and copper. In the case of brown versus white
eggs, a definitive difference in calcium carbonate amounts may be hard to uncover.

However, consider this. The color of the eggs is nothing more than a result of a different breed. The quality, nutritional value, and taste are identical between white and brown eggs, though two notable
differences are size and price. Brown eggs are usually larger and slightly more expensive. The reason
for the price increase is because brown eggs come from larger hens, which need to be fed more food
daily.

With a larger intake of calcium each day, one might expect the produced egg to have a higher
calcium carbonate content. However, since the eggs are larger, it must be kept in mind that the
calcium is spread over a larger surface area during egg formation. A brown eggshell’s increased
tendency to break, when compared to white, is often attributed to this “thinning out” of calcium during
deposition.

[Alpha-Omega]

Pasteurized eggshells:  http://www.safeeggs.com/

This link has a link to THE SCIENTIST which deescribes a machine used for pasturizing eggs in their shells:  http://www.suite101.com/article.cfm/microbiology/9367 

And so here is the link to that article:  http://www.suite101.com/external_link.cfm?elink=http://www.the-scientist.library.upenn.edu/yr1998/july/hoffert_p1_980720.html

Pasteurization Processes:  http://pubs.acs.org/cen/whatstuff/stuff/7945sci2.html

Good Luck With That!!!!

[Batcat]

Ok thank you so very much, so if i find some Calcium carbonate (since i dont need the other substances), i will get it in granulated form.
and then to make it stick to the egg (without any shell) what will i need there?

since i havent played with chemistry a lot (only for about 2-3 years) im a little untrained to see which substances will work with eachother.

[Alpha-Omega]

I think it may be a bit more involved than that.  I mean you can try it....you would need to find some recipe for a CaCO3 coating/overlay.

I am sure you can find a way to coat the eggshell.  There are many coating for eggshell now/decorative you do not want to decorate them you want to put a coating on the eggshell that acts as a barrier to Salmonella ...BUT whether a simple layer of CaCO3 will STOP the bacteria is another matter.  I believe that may be a bit more involved.  The eggshells are porous; and ,Calcium Carbonate Powder is an odourless, tasteless, non toxic and absorbent powder that is used in many products. It is a common form of the mineral supplement, calcium and is used in a variety of cosmetic products as a filler, whitener, neutralizer, pH modifier and buffer. It is also used in toothpaste as a polishing agent and combined with talc in powders to remove shine by absorbing excess oils


I think you should read this article by FSIS USDA:

http://www.fsis.usda.gov/Fact_Sheets/Focus_On_Shell_Eggs/index.asp

Can Shell Eggs Be Pasteurized?

Shell eggs can be pasteurized by a processor if FDA approves the process. Pasteurized shell eggs are now available at some grocery stores. The equipment to pasteurize shell eggs isn't available for home use, and it is not possible to pasteurize shell eggs at home without cooking the contents of the egg.

[Batcat]

yea this part

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The equipment to pasteurize shell eggs isn't available for home use, and it is not possible to pasteurize shell eggs at home without cooking the contents of the egg.
doesent make my project look that good, well i dont actually need it to work, ill just do some experiments with it, and see how it goes.

thank you Alpha-Omega for all the time you took to help me, and i will be sure to inform you if i have any success

[Borek]

Easter in Poland circless around eggs and to make it more interestiong someone inveneted a recipe for making an "ostrich egg" from hen eggs. It starts with breaking eggs and separating shells, yolk and white. Then you boil yoolks in a bladder, then you put yolk sphere in the larger bladder and you add white and you boil it again. Here comes the final part of making shell. You dry the shells and you dissolve them in as small as possible amount of concentrated acetic acid (I believe the original recipe called for 'essence of vinegar' or something like that, bear in mind recipe as I have seen it was from 18^th century and prepared for Poland). In fact you should not dissolve them completely, you should end with paste that can be used to paint the "boiled egg" already prepared. Put this painted egg in the warm place rich in CO₂ - and wait.

Disclaimer - I have not tried this recipe, I have not seen it in use and I have read it 30 years ago.

And I dont think it will help Batcat, although it may partially answer his original question.

[Batcat]

well that actually helps me a lot. cause im writing a report and i need something about the history to, i know that they probably dident do it to prevent salmonella, but it was a step in the right direction.

and yet another thing i can put in my experiment.