by-Dr.Deepak Pd.Sinha,Poultry consultant,Patna.
DR. RAJESH KUMAR SINGH, (LIVESTOCK & POULTRY CONSULTANT), JAMSHEDPUR, JHARKHAND,INDIA 9431309542, rajeshsinghvet@gmail.com
PACKAGING OF SHELL EGGS
Nature has given the egg a natural package – the shell. Despite its relative strength, the egg is an extremely fragile product and even with the best handling methods, serious losses can result from shell damage. Economical marketing generally requires that eggs be protected by the adoption of specialized packaging and handling procedures.
Functions of packaging———–
Packaging is an important component in delivering quality eggs to buyers. It embraces both the art and science of preparing products for storage, transport and eventually sale. Packaging protects the eggs from:
• micro-organisms, such as bacteria;
• natural predators;
• loss of moisture;
• tainting;
• temperatures that cause deterioration; and
• possible crushing while being handled, stored or transported.
Proper handling and storage, as seen in the previous chapter, help control moisture loss, but appropriate packaging may also help prevent it. Eggs also need to breathe, hence the packaging material used must allow for the entrance of oxygen. The material used must be clean and odourless so as to prevent possible contamination and tainting. Authentic egg packaging materials can be reused, but careful attention must be paid to possible damage, odours and cleanliness. The packaging must be made to withstand handling, storage and transport methods of the most diverse kind and to protect the eggs against temperatures that cause deterioration and humidity. Finally, consumers like to see what they are buying, especially if it concerns fresh produce. An egg package should be designed so that the customers not only recognize the product as such, but can also see the eggs they are buying.
Many factors must be taken into consideration for packaging eggs. It is important to obtain information regarding the necessary requirements for a particular market, such as:
• quality maintenance;
• storage facilities;
• type of transport;
• distance to be travelled;
• climatic conditions;
• time involved; and
• costs.
Egg packages—————-
There are many different types of egg packages, which vary both in design and packaging material used.
Type 1. Packing eggs with clean and odourless rice husks, wheat chaff or chopped straw in a firm walled basket or crate greatly decreases the risk of shell damage. An example of this can be seen in the forefront of Photograph 16.
It is also be possible to pack eggs in a simple basket as seen in Photograph17. The basket has no cushioning material such as straw and therefore damage to the eggs may occur more easily. This kind of packaging may be fit for short distance transport.
Type 2. A very common form of packaging is the filler tray. The fillers are then placed in boxes or cases. An example can be seen in Photograph 18.
Filler trays are made of wood pulp moulded to accommodate the eggs. They are constructed so that they can be stacked one on top of the other and can also be placed in boxes ready for transport. Filler trays also offer a convenient method for counting the eggs in each box, without having to count every single egg. Usually the standard egg tray carries 36 eggs. Therefore, if a box holds five trays, for example, the box has a total of 180 eggs (36 x 5 = 180).
The cases used may be made of sawn wood; however, they are more commonly made of cardboard. When using cardboard cases, special care must be taken in stacking so that excessive weight is not placed on a case at the bottom of a stack.
Fillers can also be made of plastic as seen in Photograph 19. The advantages of using plastic egg fillers are that they can be reused and are washable. The fillers can be covered with plastic coverings and be used as packages for final sale to the buyer. More importantly, however, plastic transparent fillers allow for the inspection of eggs without handling or touching the eggs.
Type 3. Eggs can also be packed in packages that are smaller and specific for retail sale. Each package can hold from two to twelve eggs. These cases can be made of paperboard or moulded wood pulp as seen in Photograph 20, or can be made of plastic as shown in Photograph 21.
It is also possible to pack eggs in small paperboard cases and cover them with plastic film. Egg cases have also been developed from polystyrene. The advantages of using polystyrene are superior cushioning and protection against odours and moisture. The package is also resistant to fungus and mould growth.
The use of small cases is restricted by availability and cost considerations. However, small cases are good for retailers and customers. They are easy for the retailers to handle and customers are able to inspect the eggs.
Labelling——————-
Labels are a source of important information for the wholesaler, retailer and consumer and not just pieces of paper stuck onto cartons or boxes. The important facts on the label contain information for buyers concerning the eggs, their size and weight and quality/grade description – AA, A or B. Labels may also indicate the producer, when the eggs were laid, how to store them and their expiration date. Persuading the buyer to purchase the product without tasting, smelling or touching is another function of labelling.
Costs of packaging————–
When calculating the costs of packaging, expenses must be considered for:
• packaging materials;
• labelling;
• labour;
• additional working capital required;
• changing existing facilities (if applicable); and
• packaging machinery (if applicable).
STORAGE OF EGGS——————
The storage of shell eggs during the main laying season, in order to conserve them for consumption when they are scarce, has been practised for many centuries.
For the successful storage of eggs, the following conditions must be met.
• The eggs placed in storage must be clean; they must not be washed or wet.
• Packaging material used should be new, clean and odourless.
• Loss of water due to evaporation should be reduced to a minimum.
• The storage room must be free from tainting products and materials and should be cleaned regularly with odourless detergent sanitizers.
• The storage room must be kept at a constant temperature and humidity must be checked.
• There should be air circulation in the storage room.
• Eggs should be stored so that they are allowed to breathe.
• As far as possible, interior quality should be monitored; there should be a good proportion of thick white, the yolk should stand up well, and the flavour of white and yolk should be good.
If all of the above requirements are to be met, refrigerated storage is necessary.
Cold storage of eggs——————-
In the tropics, eggs can deteriorate very quickly unless they are stored at low temperatures. The ideal temperature for storage in such climates is 13°C or lower (usually between 10° and 13° C). Here refrigeration is a necessity for successful commercial storage; however, it may be unavailable or the costs too high.
The most important factors in successful cold storage are as follows.
• The selection and packaging of eggs.
• The equipment and preparation of the cold store.
• Proper temperature, humidity and air circulation.
• Periodic testing for quality.
• The gradual adjustment of eggs to higher temperatures when removed from storage.
The selection and packaging of eggs for storage. ———-
Eggs for storage must be clean, of good interior quality and have a sound shell. If they are to be stored for more then a month, they should be equivalent to the U.S. grade A . Therefore, it is best to candle all eggs before storage. It may also be advisable to take a sample and to break out these eggs as a further quality check (see Chapter 2). The period of time between laying and storage should not be more than a few days. The eggs should be kept cool during that time.
Packaging materials used for storage should be new, clean, odourless and free from damage. When packaging material is reused, it is extremely important that it is clean, odourless and free from damage. It is important that the material used allow the eggs to “breathe” and to be free from tainting odours. It should also be sturdy in the event that the cases have to be stockpiled on top of one another.
The equipment and preparation of the cold store. ————-
The storage room should have a concrete floor that is washable. Walls and ceilings must also be washable. Wooden buildings have been found to be satisfactory, provided they do not impart foreign odours or flavours to the eggs. The room should be scrubbed thoroughly with hot water and soap or an odourless detergent sanitizer before being used. A final rinse with a hypochlorite solution will help greatly in deodorizing the storeroom. A liberal application of freshly slaked lime to unpainted plaster surfaces will also help. The storage room should be aired and dried out thoroughly after cleaning, then closed up and the refrigeration turned on. It is best to allow several days for the temperature and humidity to stabilize before introducing the eggs.
Proper temperature, humidity and air circulation. ————–
Careful and accurate control of the air condition is essential. A temperature between – 1.5° and – 0° C is recommended. At a temperature of – 2.5° C eggs freeze. The room should be well constructed and insulated and the refrigeration should be capable of maintaining an adequate uniform temperature in all areas. The cases of eggs should be separated by wood-strips and kept well away from the walls so as not to obstruct air circulation. Aisles left for the convenience of handling specific egg cases also help air circulation. Periodic ventilation of the storage room is advisable to promote air exchange.
The relative humidity should be between 80 and 85 percent at a cold storage temperature of – 1° C. At cold storage temperatures of about 10° C the relative humidity should be between 75 and 80 percent. In such instances, on average, egg weight loss should not exceed 0.5 percent per month. During the early stages of storage when the packaging material is absorbing moisture at a high rate, the floors should be sprinkled with clean water several times a day. If forced-air circulation is feasible, a controlled temperature water-spray air washer may be used. If the humidity becomes excessive, part of the air can be cycled through a unit containing calcium chloride. Where eggs have been oiled less attention can be paid to the humidity level.
Periodic testing for quality. ——————
Periodic quality checks are essential if the risk of heavy egg losses is to be avoided. Every month or so a sample of eggs should be selected from the various lots and tested. Usually a sample of about 1 percent of all eggs in storage may be sufficient. For example, if 3 000 eggs are kept in storage, 30 eggs sampled from various egg cases will enable a good estimation of the general quality level of the eggs. If there is evidence of excessive deterioration, it is best to dispose of the eggs quickly, after eliminating those that are unfit for consumption.
The gradual adjustment of eggs to higher temperatures——————
. Care must be taken in removing eggs from storage to avoid the condensation of moisture on shells. This is minimized by raising the temperature slowly or by moving the eggs through rooms with intermediate temperatures. If condensation occurs, the eggs should be held under conditions that allow the moisture to evaporate within a day or so.
As indicated earlier, eggs should not be stored with products that may taint them. For the long term, eggs are best stored alone, while for the short term they may be kept with dairy products such as milk and mild-flavoured cheese. The average storage life for eggs is between six and seven months.
Economics of cold storage—————
There is a tendency to underestimate the difficulties involved in providing good cold storage facilities and to recommend their installation without adequate investigation of their cost and potential economic return. The following factors should be considered when contemplating cold storage.
• Refrigeration is a complex and highly technical business.
• Capital investment and operating costs must be estimated.
• Potential available business must be appraised.
The potential available business must be appraised as well as its distribution over the different seasons of the year and the costs involved. Egg storage to even out the availability of supplies is likely to provide business for only a part of the year. The average – not maximum – price difference between the plentiful and scarce seasons must be calculated. If projected returns do not significantly exceed the costs envisaged for storage, there is little incentive for egg traders to make use of storage.
It must be considered that some egg producers, according to their circumstances and possibilities, maintain yearly production through special breeding and feeding programmes and by providing illumination in the hen laying houses. This may even out the rate of egg production throughout the year and hence long-term storage should not be considered.
How Long Do Eggs Last?———–
How long do eggs last in the fridge?
Fresh eggs will last for at least 66 days from the date they are placed into a carton, this is 3-4 weeks beyond the “best by” date normally stamped on the carton. There are many things to consider with egg safety. To properly answer the question of how long do eggs last, how long are eggs good for, or the shelf life of eggs, a variety of factors must be examined such as the sell by date and how the eggs have been stored.
The most accurate date to consider with eggs is a date placed on the egg carton by the manufacturer called the “pack date”. This date specifies the julian date (numerical day of the year) on which the eggs were packaged.
Eggs Expiration Date
Refrigerator
Past Sell By Date
Fresh Eggs are good for 3-4 Weeks
Egg Substitutes are good for 3-4 Days
Egg Whites are good for 2-4 Days
Egg Yolks are good for 1-2 Days
The shelf life of eggs is greatly reduced if the eggs are not kept constantly refrigerated as they may become unsafe to eat. Eggs should always be stored in the fridge right before and after use. But remember, eggs, like a lot of dairy products, usually have a sell by date or a “best if used by” date and not a use by date. Because of this distinction, you may safely use eggs to complement your favorite meals even after the sell by date has lapsed but please consume them prior to their eat by date. Practicing proper hygiene and food safety techniques will help prevent foodborne illness.
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How to store Eggs to extend their shelf life————
Proper food storage is key to extending the shelf life of foods. You can help eggs keep fresh longer by storing eggs in the their original container in the refrigerator. Storing eggs in this fashion will help keep out moisture and other contaminants.
Freezing is not recommended for eggs because after freezing and thawing the eggs will turn into a thick clumpy paste. So, if you want to freeze your eggs to extend their shelf life, it is best to crack the eggs into a freezer safe container and gently blend in 1/2 teaspoon of salt before freezing. The eggs can then be thawed and used, but these eggs will not rise much if later used in making baked goods. If you do this, also be sure to thaw the frozen eggs in the refrigerator before using.
