Cornell University researchers found that in order to protect cow's milk from damage from LED lighting, it needs to be packaged differently, according to the Dairy Reporter. But there will be pressure to develop containers that are similar to what consumers expect, or shoppers may need to be educated about why different milk packaging is necessary.
The study concluded that both LED and fluorescent light can cause off-flavors in milk, and while antioxidant enrichment did provide protection, it modified milk flavor in other ways, researchers said.
The scientists recommended further research to better understand how light-oxidized flavor is developed, the optimal wavelength spectra to avoid this result, and the nutritional losses that occur during exposure. Their study was published this month in the Journal of Dairy Science.
Prior studies have concluded that packaging is important to keep milk quality from sustaining light damage and that some type of protective containers will probably be needed in the future. Also, consumer response to LED-exposed milk has varied, depending on the amount of exposure and the kind of milk involved.
The Cornell researchers found that light-protective containers provided the most effective protection and that LED-exposed milk packed in PET (polyethylene terephthalate) bottles did not result in off-flavors when tested by trained panelists. In fact, the milk samples in PET bottles got the best ranking as far as aroma and flavor when rated by consumers.
One Illinois dairy recently switched from clear to amber glass jugs to preserve the milk's taste from light exposure — similar to how beer brewers use amber or brown glass to keep their products fresher. The dairy decided to put up store signs explaining why they switched to a different colored container and said they were confident consumers would accept the change after a shakeout period.
Some major retailers have experimented with different types of milk packaging, but for sustainability purposes and cutting overhead rather than for protection from light damage. A Kroger-owned dairy in Virginia has made gallon plastic jugs for milk and other beverages with 10% less plastic than traditional jugs — and which are also completely recyclable.
Other milk packaging innovations have focused on either preventing food spoilage, such as containers with silver nanoparticles that can extend milk's shelf life, or on reducing packaging waste, such as biodegradable plant-based packaging.
Dairy-based milk is sold in Europe in shelf-stable asceptic packaging, which doesn't need refrigeration until it's opened, and most brands of U.S. plant-based milks are also sold that way. According to one critic of putting cow's milk products in asceptic containers, the U.S. dairy industry would suffer more than it already has from declining sales by losing access to the big lighted grocery store display cases that both attract customers and keep milk cartons cool.
While it makes sense to package milk in a way that protects the quality and the sensory aspects, it needs to be done so that customers still recognize the product and the appearance doesn't scare them off. It would also be best if the new protective packaging were completely recyclable or otherwise reusable. That's a tall order for any food or beverage product, but with scientific minds trained on the problem, a workable breakthrough may not be far off.