Sunday, July 7, 2013


Egg is a unique food that is considered almost complete with respect to most essential nutrients required for a normal health. Unfortunately the human world is divided into two succinct groups based on the dietary habits. One group eats practically every thing that is edible on this planet while the other one abhors most foods of animal origin that include meat, fish and poultry. In between there are sub-groups who take milk called lacto vegetarians and others consuming eggs called ovo vegetarians. Newer generation of vegetarians do not have inhibition in giving egg and products based on it to their children, realizing that it provides the best nutrition to growing children along with milk as most plant sources of proteins are inferior to milk and egg in terms of amino acid make up and protein efficiency ratio. 

Egg industry is big business and has a powerful lobby that protects its interests. Though egg can be from a variety of creatures that include Chicken, Duck, Quail, Roe and Caviar fish, most commonly consumed comes from Chicken. As its unique nutritive role is well established many countries classify egg as a meat food. Chicken egg is a historically important food its antiquity dating back to 7000 BC. To day world consumes annually about 65 million tons of eggs produced by about 6.5 billion Hens. Besides its high value proteins present in the white portion ( 12-13%), egg is also a rich source of Vitamin A, B2, B6, B9, Choline, Iron, Calcium Phosphorus and Potassium. though 75% of its weight is accounted for by water! Controversy surrounding the dangers associated with regular egg consumption is so confusing that many health pundits opine that healthy individuals should not take more than 4 eggs a week to avoid developing diseases like CVD, Stroke, Diabetes etc. The rationale of this view is that egg is a rich source of Cholesterol (424 mg %), triglycerides (10-11%) and lecithin, all considered villains of peace as far as human health is concerned.

Fear of Cholesterol and fat keeps consumers away from the egg. Is this justifiable? Probably not, because at moderate consumption level and with normal physical activity, egg cannot do any harm at all. After all both Cholesterol and fat are normal biologically relevant nutrients which are metabolized in the body. Still egg poses some challenges in terms of health hazards because of the recent finding that the lecithin present in it can produce artifacts in the intestine such as TMAO which facilitates plaque formation in arteries leading to heart damage. Also true is the potential allergy caused by egg white to many consumers. Due to unsatisfactory hygiene conditions in many egg producing facilities, one of the biggest threat to egg industry is fatal contamination with Salmonella which is known to kill scores of people every year. If egg consumption can raise the chances of heart attack because of its association with TMAO formation through action of intestinal bacteria and Salmonella threat perception becomes serious in the coming years, what is the alternative to it for consumers who are used to egg consumption in the form of boiled egg, fried egg, omelet, scrambled egg and many other products containing egg solids?. Here comes an interesting development which speaks of vegetarian egg!

Many ovo vegetarians consume egg because modern day egg is an unfertilized one incapable of forming live birds on incubation and thereby justify its consumption. As for regular egg consumers Salmonella infection is sought to be addressed by vaccinating the birds in countries like England against this pathogen. Some ovo vegetarians are put off by the fishy smell due to generation if Triethylamine when feed materials contain rape seed meal or soy meal. The so called "Plant Egg" is not an egg possessing the shape of the regular egg but at best an egg powder analog that can be used in many food preparations containing egg solids. It cannot make a boiled egg like product or a fried egg but preparation of omelet and bakery products is possible. 

Scientific efforts in creating  products from plant sources similar to meat or egg have been going on for quite some time and there are a few products already being marketed with some success. In India soy chunks and granules are used to at least extend the meat used in preparations cooked at home and thus save some money. But except for texture these meat substitutes do not measure up to the expectations of the consumer. Similarly there are egg substitutes made from plant proteins which are not easily accepted by those used to natural egg. It is against this background that a new claim is being made recently by a US company regarding development of egg powder like product which cannot be distinguished from egg powder made from chicken eggs. How far this claim is substantiated is not clear as it is not yet launched commercially.

The USP of chicken egg is the extraordinary properties of the proteins present in it which help to make many products from it. The proteins in the yolk coagulates at a temperature of 150-158F while that in egg white gets coagulated between 145F and 165F and this phenomenon is responsible for the unique texture of preparations like boiled egg, fried egg and omelet. To replicate this has been a Herculean effort for the scientists as most plant proteins are more heat resistant and the protein texture when coagulated does not match with that of chicken egg. This is sought to be addressed by screening a vast array of plant species to identify those capable of mimicking egg protein. The new development is based on discovering plant protein sources which resemble the egg protein in their response to heat.    

Eggs have also some amazing properties, such as the ability to enable oil and water-based foods to mix permanently. The challenge to create a genuine substitute for the egg is daunting as such replacements should also match the latter in terms of nutrition which calls for massive studies involving proteins from different edible plant sources. If the claims made so far are to be believed a few baked goods can easily be prepared using egg replacements from plants with barely any difference. One of the species of plant from Asia it was found that its proteins coagulate and turns solid, with heat  similar to the process that scrambles the eggs. With present state of knowledge, plants like the one identified it should be possible to create hundreds of products that can provide the culinary pleasure to the carnivores without going through the animal route. 

Animal system is increasingly being criticized for some of the ills the world is facing to day including global warming. In general livestock is considered environmentally taxing producing 51% of greenhouse emissions due to flatulence. Besides considerable acreage of land is locked up in rearing them. Added to this, according to some calculations, livestock consume more food than it would take to feed the 1.3 billion people in this planet who go to bed hungry every night! Probably the world will have no option but to turn to the plant kingdom to sustain itself before long!


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