Guidance Note-Egg Quality and Safety

Maintaining the freshness of eggs:

• Eggs maintain their freshness for up to 10 – 12 days, after they are laid, at room temperature of about (28+2°C), but the shelf life will be shorter at higher The important factor in maintaining egg freshness is mainly temperature while humidity also affects the same to some extent. Storing the eggs, in refrigerator, in designated shelves or egg cases is the best way to maintain their freshness.
• To maintain egg freshness and performance, buy the eggs from stores that keep the eggs at cooler temperatures (air-conditioned stores or supermarkets) or stores that keep the eggs in well ventilated covered places and maintain ambient
• In most cases, eggs that are clean, free of visible defects or cracks and bought from a place that stores eggs under cooler temperatures will remain fresh for 4 to 5 weeks from the time they are laid provided that the eggs are stored in their carton in Beyond this period, the egg quality starts to deteriorate.
• Consumers should strictly avoid handling eggs roughly and leaving them in hot vehicles or places where temperatures are very Refrigerate the eggs once you reach home.
• Do not use dirty or cracked Cracked egg shells are a perfect foil for bacterial infections and the dirty eggs may also contaminate other food stuffs. Dirty eggs may be contaminated but may not still smell bad. Avoid washing dirty eggs, as they would become more porous when wet, thus making an easy entry for bacteria inside eggs.
• If an egg is cracked or too dirty, dispose it
• Always wash your hands thoroughly with soap and water after handling
• Feed quality is also an important factor affecting the overall quality of Eggs produced by farmers who used castor seed cakes as source of protein were reported to have rubbery textures. Therefore, poultry feed used in poultry farms should be approved by concerned regulatory bodies like BIS, etc.

Testing eggs for freshness:

• Fresh egg, when held against a very bright light in a dark room, will display a small air gap usually at the broader (blunt) end of the As the egg ages, the air cell expands in volume. Upon hard boiling a fresh egg, you can clearly see the indentation left behind at the top of the egg once the shell is peeled off.
• In case of fresh eggs, the yolk normally stays in the centre and is not very mobile because of the chalaza (the strings of tissue) that hold it in place. These strings break down as the egg ages (during storage or transportation). When hard boiled eggs are cut length wise, one can see that the yolk has moved off the center.
• A quick test to check freshness of an egg is to immerse it in a mug or basin of water. Fresh eggs would remain at the bottom width wise, older eggs would remain at the bottom on one end while the stale/rotten once would float because of the larger air cell. It is to be noted that sometimes weak shell and fine cracks can also cause the egg to float.
• When broken out of the shell, good quality, fresh eggs display certain characteristics as mentioned below:
  • The yolk would be rounded, small and stands high in a thick and gel like egg white. The gel like mass of egg white does not spread over a wide area but tends to stay compact. As the egg ages (With storage and temperature associated with storage), the egg white becomes thin and runny and finally egg yolk and white dissolve into each other in older or rotten eggs. The older eggs may also develop rotten odour and would have lost the typical egg odour.
  • With the aging of egg and the white becoming thinner, one can clearly notice that it will take a longer time to whip into foam, and when whipped the foam is less stable or collapses faster. However, it is also important to note that the very fresh eggs also do not foam well and take longer time; but once beaten the foam is very stable as compared to older eggs. The maximum and better foam volume/stability can be obtained from three or four day old eggs.

If not stored properly, eggs become plastic-like

The way eggs are stored is an important as for how long they are stored. Eggs can lose as much quality in one day at outside high temperature as 4 to 5 days in the refrigerator. Eggs kept at room temperature can maintain their freshness for up-to 10-12 days after being laid, but the shelf-life reduces with increase in storage temperature.

While transporting and storing eggs undergo different temperature. Due to this the air cell in the egg increases in volume, loses water content from the yolk and albumen due to evaporation through the shell. The chalaza, a funnel shaped proteinaceous matter connecting the yolk and albumen starts disappearing and finally the egg loses its weight. The increase in the air cell volume can be easily detected by piercing the broader end of the egg with a pin. A normal eggs does not give away easily while an older egg simply gives due to increased air cell.

As a consequence of water loss in eggs, the egg white and yolk portions shrink followed by mixing of these two portions. Both these portions dissolve into each other, and when such an egg is broken it does not give a separate egg yolk or white giving the impression of a fake egg. Further, the smell of mixed yolk will not have the typical odor one associates with a fresh egg. Moreover, the shell membrane in a normal egg is slimy and appears smooth. With the loss of moisture this membrane becomes dry and has a paper like appearance and texture. This again creates the impression that the egg could be plastic or fake. One should note that the membrane of a fresh egg would take time to burn when held against a flame, while the membrane of the older egg would burn quickly due to its dryness, but both would produce the same kind of ash without a hint of smell that is normally associated with burning plastic.

Consumer can find out if the egg us genuine by simply dipping the shell pieces of suspected fake egg in strong acids (like 2N Hydrochloric Acid). Calcium Carbonate, being the major component of egg shells, will dissolve the shells in the acid. Alternatively, egg or eggshells when placed in vinegar will dissolve the shells slowly but will start giving out bubbles. The membrane of such acid treated shells will have no adhesion to the shells but will almost have the texture of a paper or thin plastic.

Myth about egg Quality:

• Plastic or fake eggs
  • No. plastic or fake eggs are a myth mainly due to (a) economics involved in preparing a plastic or fake eggs and (b) inability for anybody to make a composition similar to natural egg.
• Bad or rotten eggs always smell bad
  • Egg can smell and taste fine and still have salmonella. Also, bacteria on the shell can get inside if the eggs are cracked; and can also find their way into other foods if kept in contact. However, if an egg does not smell bad, never use it.
• Dirt or chicken shit on eggs indicates that eggs are organic and natural
  • Certainly, the dirt is an organic material but it is neither safe nor good for health. Chicken shit may contain harmful bacteria, mainly salmonella. It is advisable that such dirty eggs be discarded.
• If eggs, are dirty wash them to remove dirt 
  • No, eggs become porous when washed. hence never wash eggs. Washing normal or dirty eggs may allow the harmful bacteria to enter into the eggs.
• Eggs remain fresh if stored at room temp. and need not to be refrigerated
  • Refrigerating eggs keeps them fresh for longer duration as compared to storing them at room temperature and also minimizes the risk of any bacterial growth.
• Egg is a better source of Protein, minerals and vitamins than milk, and hence providing raw egg to someone sick will provide then protein and minerals
  • No. Never give raw egg to anyone including pregnant women, infants or older people as eating raw eggs enhances the risk of Salmonella infection. It should never be given in raw form to those who are seriously ill. especially when they are sick. It is preferably better to consume cooked eggs in which egg white is firm and yolk is completely thickened.
• Uncooked(raw) eggs are better source of proteins and nutrients
  • No. Drinking eggs in their raw form or in the form of milkshakes with raw egg white is the risker way of consuming eggs. Cooking eggs does not reduce the protein content or nutrients present in them to an unavailable form.
• The egg float test can clearly differentiate good and bad eggs
  • The float test can differentiate fresh and older eggs. But, it never differentiates the goodness of the egg in terms of Salmonella contamination.

For Traders & Retailers:

• Source eggs from credible sources only
• Traders and retailers can minimize the decline in egg quality by observing the following basic guidelines:
  • Have adequate and cool holding places to store eggs (preferably refrigerated)
  • Avoid storing eggs close to strong smelling food or food products
  • Store or display eggs away from sunlight
  • Strictly rotate the egg stocks on FIFO basis
  • Avoid transporting eggs in hot vehicles or hotter temperatures
  • Advise to consumer to store eggs in cooler temp. or refrigerators
  • Immediately discard any cracked or dirty egg
  • Do not sell dirty eggs to consumers

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