Supermarket light affects taste and nutrient content of milk, study finds

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LED lighting on supermarket shelves is reducing the nutritional value of milk and shortening its shelf life, finds a new study by researchers from Newcastle University.

The report, Milk: Light exposure and depletion of key nutrients, reveals that high-intensity lighting, such as that found in supermarket dairy cabinets, reduces essential nutrients found in milk, such as Vitamin A, Vitamin B2 (riboflavin) and Vitamin D.

After two hours of exposure to LED lighting – the type found in supermarkets – milk begins to lose vitamin A. After 16 hours, it has half the amount expected. The report also shows that riboflavin can decrease by 28 percent after just 20 minutes of indoor light exposure.

“The damaging effects of light can be influenced by the light intensity and time of exposure, so longer exposure to light causes milk to deteriorate faster,” said Catherine Birch of the School of Natural and Environmental Sciences at Newcastle University.

With around half of all milk remaining on display for at least 8 hours, a significant proportion of milk on retail shelves is at risk of light damage if it does not have any form of light-protected packaging, warned the report, which is a review of the available scientific literature.

The report notes that light-protected packaging can reduce or prevent light damage to a great extent.

Laboratory testing on milk found that while the light-protected milk retained almost all Vitamin B2 and lost only 16 percent of Vitamin A while non-light-protected milk lost all Vitamin B2 and 93 percent of Vitamin A, it says.

The report comes ahead of a Dairy in the Dark interactive grocery store pop-up in London, to be held 27-30 May at 230 Portobello Road, London. The event will bring to life an extreme example of how milk’s nutrients and taste can be preserved without light protected packaging.