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Cracking egg fraud: Phospholipid marker for farming conditions
Eggs produced by hens raised in cages can be distinguished from those produced in barns from the differences in lipid content, say researchers in the UK, who made their discovery using non-targeted metabonomics.To get more news about Quail egg machinery, you can visit dinneregg official website.
In the murky world of food fraud, the humble egg might seem an unlikely target but there are big profits to be made by mislabelling eggs laid by caged birds as those laid by hens brought up freely in barns. They are still not free range but they have more freedom than caged hens. According to EU rules, chickens in barns should be kept at a maximum density of 9 birds/m2 of usable area. This compares to the more congested conditions of caged chickens which must be allowed to occupy an area of at least 750 cm2, of which 600 cm2 must be usable, allowing the birds to perform natural behaviour like nesting, roosting and perching.
Although barn hens are freer to move about, they are still susceptible to disease so are given antibiotics regularly, as well as hormones to increase egg production, the same as caged hens. Nevertheless, with the focus of consumers on animal welfare, many are willing to pay more for food that has been raised under better conditions, so barn eggs can command a a higher price than those laid in cages.
Several analytical methods have proposed to distinguish between cage and barn eggs, based on the content of cholesterol, fatty acids and various elements. Each of these methods was aimed at specific classes of components in the egg. Researchers in the UK have taken a different approach by applying a non-targeted metabonomics method to see if there were any differences in the profiles of small molecules across all classes.
David Thompson, Amy Johnson and Kate Sidwick from Keele University, Vasil Pirgozliev from Harper Adams University, Newport, and Anthony Edge from Liverpool University used LC/MS on a medium resolution time-of-flight mass spectrometer as the screening technique. They analysed extracts of the yolks of fresh eggs from six caged hens and six barn hens, separating the compounds present on a reversed-phase HPLC column for analysis by electrospray ionisation ion positive-ion mode. Previous studies had revealed that there were few compounds in egg yolk that were susceptible to negative ionisation. |
