Where there’s egg there’s crime. There really is no aspect of our lives, or our diets, that hasn’t been infiltrated by villains.
Because organic eggs are considerably more expensive than battery eggs, they are susceptible to fraud. After all, they all look pretty much the same. Don’t be fooled though: there is a world of difference in terms of nutritional value between a battery egg and an organic egg. Crack that egg and you can even see it – the truth lies in the yolk. That yellow pigment, so bright in organic eggs, so insipid in a battery egg, is evidence of the carotenoid content. Carotenoids, you may recall from an earlier blog (Life-long sunscreens: natural protection from carotenoid pigments in plants – 13 February) are those yellow pigments found in plants that act as antioxidants, protecting the skin (and eyes) from sun damage.
Some clever boffins, happy to embrace a good challenge and fight crime wherever they find it, have come up with an ingenious way of testing batches of eggs to determine their provenance, i.e. whether they were born in a barn, or into a privileged, free range or organic lifestyle. A method of selective fingerprinting (profiling) of eggs has been developed in the Netherlands, which can identify organic, free-range and barn eggs by examining the carotenoid content of the egg yolk. Organic eggs come from hens with the best diets, thanks to their organic natural feed and to the amount of freedom they have to forage for grubs, worms and seeds. This affects the carotenoid levels, and organic eggs have been found to have distinctively high levels of two particular carotenoids, namely lutein and zeaxanthin. These are the two carotenoids believed to decrease the risk of developing age-related macular degeneration, or failing eyesight as you get older.
The nutrient content of an egg is not genetically encoded – rather, it is a reflection of the hen’s diet. Eggs laid by free range hens have been found to have 38 per cent higher vitamin A and twice as much vitamin E as those laid by their caged sisters. Organic, free-range eggs also tend to have a higher omega-3 fatty acid content than battery eggs.
The BBC ran an item yesterday about the price of eggs being set to rise, since an EU ban on battery hen cages came into force on 1 January. British chicken farmers are a bit miffed because they’ve spent a lot of money converting their battery cages into ‘enriched’ cages, but it turns out that 13 EU countries have ignored the ban, so we can’t import their now illegal eggs. The result, we are warned, will be soaring egg prices. The BBC had a short film showing the new cages of laying hens which have been enriched with extra space to nest and roost.
I watched this video several times on-line and frankly couldn’t see any difference between the old battery cages and these new, enriched ones. Still, they must be better, so I’ll take their word for it. Much more visible is the quality of the organic, free-range egg – crack one and see.
Karsten, H.D., Patterson, P.H., Stout, R. & Crews, G. (2010) Vitamins A, E and fatty acid composition of the eggs of caged hens and pastured hens.Renewable Agriculture and Food Systems, 25:45-54.
Sparks, N.H.C. (2006) The hen’s egg – is its role in human nutrition changing? World’s Poultry Science Journal, 62:308-315.
Van Ruth, S., Alewijn, M., Rogers, K. et al (2011) Authentication of organic and conventional eggs by carotenoid profiling. Food Chemistry, 126:1299-1305.