Previously, testing relied on expensive and slow gas chromatography to measure levels of fats in milk, which vary between grass-fed and indoor-raised dairy herds. The new technique using fluorescence spectroscopy to instantly measure chlorophyll content in milk by shining light at the sample. The more chlorophyll, the more fresh grass the cow has eaten.
Industry players are already interested in using the new technique to validate their claims. One company is even marketing milk from cows fed a 100% grass diet.
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