During the dark season light gains special meaning. Light is said to be good for the soul. Yet very few people know that light lends a special flavour, too.
Light is scarce at this time of year. It's no coincidence that Christmas – also known as a festival of light – is celebrated during the shortest days. People need light to survive. If we get too little of it, our wellbeing and health can suffer. Some people have even been reported to exist solely on light.
While this is nonsense from a scientific perspective, what has been scientifically proven is that light adds a certain flavour to food. Unfortunately, light doesn’t taste quite as good as it looks. Indeed, it is an undesirable flavour, a so-called off-flavour which develops when food is exposed to light. In milk products, the flavour created under light exposure is slightly metallic in taste. As if you were chewing on a piece of aluminium foil.
Black layer inside packaging
This is caused by a chemical reaction among the substances milk contains, which is triggered by light (for those wanting to know more, just google “Strecker degradation”). The substance created in the process, methional, causes an off-flavour even in low concentrations. The “damaging” light may be coming from warehouse lighting or the lights in retailers’ refrigerators. The process is accelerated depending on the intensity of the light. Just a few days of regular light exposure can be enough, however, to have an impact. The off-flavour is most easily avoided using good light protection. This is also the reason why our UHT plastic bottles have a black inner coating. A normal, white plastic bottle is sufficient for pasteurised milk due to its short shelf life.
Stress testing in light fridges
To evaluate the impact of light on its products, Emmi has so-called “light fridges” in which the light is on around the clock. This is the ultimate stress test for new recipes and packaging. And as LED light technology is becoming increasingly widespread, our light fridges have also been fitted with LED lights. No matter what stress life throws your way, we at Emmi would advise: better to have some slightly light-flavoured milk than try to survive on light alone! The former is guaranteed not to harm you.