Are you sure that’s organic?

Rebecca C. Jernigan, rebecca.jernigan@laurin.com

Organic foods are in great demand, and consumers are willing to pay higher prices for the reassurance that their food is natural. However, as with any profitable market, there is always the possibility that some unscrupulous person will take advantage of the trust placed in organic labeling and attempt to sell nonorganic items with misleading labels.

How could anyone tell? Regular milk doesn’t look any different from organic.

Joachim Molkentin, a scientist at the Federal Research Institute of Nutrition and Food just may have the answer.

In a study reported earlier this year in the Journal of Agricultural and Food Chemistry, he describes the differences between conventional and organic milk in Germany, noting that a cow’s milk is influenced by what it is fed: Organic milk results from higher levels of fatty acids and different carbon-isotope ratios.

His research also found that cows that produce organic milk are usually pasture-fed, consuming plants such as grasses and clover, which increase the amount of the fatty acid α-linolenic and reduce the carbon-isotope ratio present in their milk. Cows that produce regular milk generally eat corn.

Using gas chromatography and mass spectrometry, Molkentin tested 286 samples of organic and regular milk – three brands of each – from retail stores in Germany over the course of 18 months. The extended time frame for testing was to take into account seasonal changes in the cows’ diets. He determined that the organic milk always had an α-linolenic acid content of 0.5% or more and a carbon-stable isotope ratio of less than –26.5%. Conventional milk occasionally could contain equivalent amounts of α-linolenic, but the differentiation between regular and organic milk could be improved by using time-resolved comparison of the data.

Although Molkentin’s results are specific to milk produced in Germany, further research may be able to find similar differences between organic and nonorganic items in other countries, leading to a standard for their production as well as to reassurance for consumers.