But light, even harmless LED lights, can have ill effects on grocery items, according to a new study from Cornell University, which shows milk is being degraded even as shoppers scan the shelves. Light can trigger undesirable chemical reactions in milk; notably riboflavin, an essential nutrient, is destroyed quickly by exposure to light. This degradation triggers other reactions e.g. fats and proteins are oxidised, creating unpleasant flavors sometimes described as ‘metallic’ or ‘cardboard-y’. The study compares consumer preferences, measuring testers’ liking for milk stored under typical LED light for different times. The results are pretty crazy: testers greatly prefer milk kept well away from light.
