Iowa State’s New Organic Milk Testing Method

Reader Contribution by The New Food Economy
article image

For milk to be considered organic, it is required that the cows producing the milk have outdoor access, and must spend at least 120 days a year outside with fresh grass to eat. However, recently there is reason to believe that this is not always happening, and that farms are finding a way to cheat this system while maintaining their label as an organic product.

The Washington Post’s Peter Whoriskey published an exposé, accusing Colorado’s Aurora Dairy company of serious fraud, claiming that the organic company does not let their cows graze outside – at all. The average organic dairy farm has around 100 cows, while larger Aurora Dairy has approximately 15,000 cows. Whoriskey reported that every time visited the property, the fields were empty, which was confirmed by satellite images. Aurora Dairy denied the allegations, stating that the cows “happened” to not be out the day of each “drive-by”. To prove his point, Whoriskey tested the milk; organic milk produces more good fats in the final product, and when Whoriskey tested Aurora’s milk, he found that it was chemically closer to conventional milk.

This is only one example of an organic-labeled dairy that may be cheating the system and charging the more expensive organic price for non-organic milk. While there are methods of discovering the liars among the honest dairy farms, most methods are incredibly time-consuming and costly.

However, an Iowa State study may have found a new and immediate way to test for the real deal amid the organic milks. The Iowa State scientists used Fluorescence Spectroscopy—a method that can be thought of as a kind of molecular fingerprinting, one that involves beaming light at the product and measuring for luminescent signals in response. With this method, the results re visible immediately, saving the time and money it would take to send samples to a lab for testing. Not all foods are able to be tested this easily with this method, but organic cow’s milk should have lingering traces of chlorophyll that have been metabolized by the cow.

“Spectroscopy is easy,” says Jacob Petrich, an ISU biochemist who co-authored the study. “There’s really no sample preparation involved. You just need to shine light on the sample, and there are signatures in the milk that you can see. There’s very little preparation to be done, and you get the answer almost immediately.”

The research team tested their methods using Radiance Dairy, a pasture-based dairy farm where the cows’ diet is comprised of 85 percent pasture grasses, as a control sample. The control samples showed a chlorophyll concentration of about 0.13 to 0.11 micromolar. Store-bought organic milks ranged from 0.09 to 0.07 micromolar, and conventional milks came up in numbers as low as 0.04 to a mere 0.01 micromolar.

Logan Peterman, an agricultural research manager at Organic Valley, the country’s largest organic dairy cooperative, believes that Spectroscopy could level the playing field for dairy farmers, and help make the process behind organic milk more transparent. “Human ingenuity is incredible,” Peterman says. “I would say one of the things human beings are the most gifted at is cheating.” Organic Valley hopes that Spectroscopy could also bring potential finical benefits; if Spectroscopy could help a more transparent, it would also make a new premium market, in which consumers would bring their business to organic milk products that are verified by science, instead of spending money on a fake.


This press release is presented without editing for your information. MOTHER EARTH NEWS does not recommend, approve or endorse the products and/or services offered. You should use your own judgment and evaluate products and services carefully before deciding to purchase.