The potential effects of light on milk are well documented. Studies on this phenomenon were conducted in
Europe as early as 1889 and research on the subject began in North America in the early part of this century.
Yet, despite extensive studies, there is little agreement on the exact light intensity and length of exposure
needed to produce significant damage to the nutrients in milk. Why, then, has this topic received so much
The total consumption of milk grew significantly during the early 1980ís. Since 1985, however, the growth has
slowed. Today almost all milk is purchased in retail outlets such as supermarkets and convenience
stores. Home delivery of milk has essentially disappeared. During the same period, the one-gallon bottle,
produced from high density polyethylene (HDPE), became the preferred package for milk. Consumers have
shown a preference for the HDPE bottle for a number of reasons, including ease of handling, resealability, and
the ability to see the fill level in the package. Initially, HDPE replaced glass bottles, but, since 1971, its growth
has come directly at the expense of paper cartons.
Surveys have shown that, depending upon the market area, the average time milk stays in a dairy case ranges from under five to slightly more than eight hours. Dairy case lighting is usually the most intense and potentially the most harmful to the milk, so it is critical to protect it at this point. The use of properly-formulated pigmented HDPE containers can significantly reduce milk oxidation and vitamin depletion.