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Commercial Beverage Displays and Refrigerated Merchandiser Lighting

Beer and wine connoisseurs know that light is very damaging to the taste of white wine and beer. The same is true of other commercial beverages including fruit juice and cider even in refrigerated merchandisers. After a few minutes of exposure to merchandiser lighting, beer, wine, and juice become “light struck” and can taste and smell like skunk, cooked cabbage, garlic, or onion. These effects are minimized with Promolux lamps, which emit low levels of UV and damaging visible spectrum radiation.

For wine and beer science references and excerpts click here.

Beer Displays in Commercial Refrigerators

Ultraviolet and harmful visible spectrum radiation from the sun or from retail display case lighting initiates a photochemical reaction in beer that produces mercaptans, a group of organic compounds that includes the chemical skunks spray on their enemies. Beer that has been light struck tastes and smells like skunk spray, and is often referred to as skunky.

Clear glass offers no protection against the light struck effect, and amber glass reduces the effect only slightly. When in clear glass bottles, beer can become light struck in thirty seconds, while beer in amber glass bottles will become light struck in two minutes.

Refrigerated beer display cases are often brightly lit, which affects the taste of bottled beer. Because light cannot penetrate beer cans, canned beer is not likely to be light struck.

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Retail Wine Shop Merchandising

When wine is exposed to sunlight or wine display case lighting, a chemical reaction is initiated which produces compounds known as mercaptans. Mercaptans cause the wine to smell and taste like skunk spray, sulphur, rubber, onion or garlic, or cooked cabbage.

This light struck effect occurs in white, rose, and sparkling wines more often than in red wines, because white and rose wines tend to be in clear bottles to show off their delicate colors, while red wines are usually in dark bottles, which protects the wine from the adverse effects of light.

For centuries, wine connoisseurs have stored wine in dark, cool cellars, which is the best way to preserve the full flavor of the wine. In some liquor stores, wines are showcased under high intensity lights such as hot spotlights, halogens, or metal halide lamps, while wine displays in supermarkets are often lit by bright fluorescent lights. All of these lighting sources emit ultraviolet light and damaging visible spectrum radiation, which can lead to the light struck effect.

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Supermarket Fruit Juice Displays in Refrigerated Cabinets

The flavor, taste, and appearance of fruit juices can be affected by direct exposure to ultraviolet and visible spectrum radiation from display case lighting when juices are packaged in clear containers. Compounds called mercaptans are created when juice is exposed to light, giving fruit juices a taste and smell reminiscent of skunks, onions, garlic, sulphur, or cooked cabbage.

Freshly squeezed juices such as orange juice are quite sensitive to the damaging effects of light, and will spoil more quickly when exposed to ultraviolet and damaging visible spectrum radiation, especially if the juice has not been pasteurized or does not contain preservatives.

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Promolux True Color Definition Lamps

Promolux balanced spectrum lamps emit lower levels of heat and ultraviolet radiation than regular supermarket fluorescent lamps, thus protecting beverages from the light struck effect. Compared to other fluorescent lighting, Promolux lamps emit 86% lower UV B radiation, a shorter wavelength that penetrates and causes heating, and 52% lower UV A radiation, a longer wavelength that tends to affect surfaces.

Because Promolux lamps are designed for true color definition, they have a more balanced visible spectrum than other fluorescent lamps. The yellow and green wavelengths that are predominant in regular fluorescent lighting are the most damaging wavelengths in the visible spectrum. Promolux lamps emit a more balanced range of wavelengths, including more of the red and blue wavelengths and more moderate levels of the yellow and green wavelengths.