Archive for August, 2007

About Supermarket Lighting and Shelf Life

Monday, August 6th, 2007

Promolux Safe Spectrum lighting helps keep food displays appealing and safe on the shelf.

Supermarket customers pay a lot of attention to selecting food for flavor and nutrition, and most of us assume that food from the supermarket shelf are both palatable and safe. Describing foods as diverse, complex and active systems, in which microbiological, chemical, enzymatic and physicochemical reactions can simultaneously take place, T. P. Labuza, food chemist from the University of Minnesota, points to a complex challenge all retailers of perishable foods face: that of delivering to discerning consumers a range of top quality food products that are always subject to deterioration and damage from the environment.

Grocers use the term to describe a period of time that a perishable food remains marketable acceptable enough for consumers to make the purchase. Many fresh foods are marked with an expiry date, after which the store can no longer guarantee the safety of the foods. Expiry dates are really educated predictions based upon data gathered from experience and knowledge of specific conditions and give consumers a general indicator of freshness.

Food retailers know that a longer shelf life means better profits, so providing optimal storage conditions for fresh foods like fruit and vegetables, meats, fish, and bakery products is of prime importance in the grocery industry. A lot of money is spent creating and maintaining well-lit, attractive displays, but the visual appeal may not last long enough. Changes inevitably occur in foods displayed on the shelf.

For retailers to effectively maintain the quality of perishable foods and to protect food safety, Labuza says, they require three things: understanding of these reactions, the influence of the environment and the successful limitation of the ones most responsible for spoilage or loss of desirable characteristics.

Deterioration of perishable food is accelerated when foods are on display, due especially to exposure to heat and light. Commercial lighting is often a source of retail food storage problems that mean shorter shelf life and wasted food. When exposure to light and heat are controlled, photo oxidation and loss of nutrients can be reduced. The correct supermarket lighting can reduce supermarket losses and translate directly into better profits for a more viable business.

Specialty lighting designed specifically for the food industry should meet stringent criteria of both low heat emissions and low levels of UV radiation. Promolux balanced spectrum lamps fulfill the expectations. Compared with everyday fluorescent and incandescent lighting products, Promolux lamps emit lower levels of heat, less ultraviolet radiation and reduced levels of damaging visible spectrum radiation.

Commercial lighting and heat emissions.

Bacterial contamination can occur at any stage in the food delivery chain and at a low level is not considered particularly harmful. Even though refrigerated cabinets and chilled ice beds are used to extend the shelf life of dairy products, meat, seafood and other fresh foods, commercial light fixtures can radiate enough heat to accelerate bacterial growth.

Bacterial growth must be controlled, especially when foods are left to sit on the supermarket shelf under hot lamps, where organisms can multiply rapidly to a toxic level capable of causing food poisoning in humans. Because Promolux food safe lamps emit less heat than everyday lamps,  bacterial growth is controlled and drying and shrinkage reduced.

Commercial lighting and ultraviolet emissions

Ultraviolet  light is electromagnetic radiation not visible to the human eye. UV radiation from artificial lighting can be responsible for photochemical changes that occur in the lipids, or fat, components of meats and other foods. Lipid oxidation causes off-flavors and eventually rancidity. UV radiation also damages sensitive food color pigments and other additives and leads to fading or discoloration and loss of visual appeal.

Both fresh bulk foods and packaged foods deteriorate while displayed under retail lighting. J. C. Acton from Clemson University, SC, advised that while modified atmosphere packaging or use of barrier films may reduce the rate of product deterioration, lighting environments, similar to temperature environments, will provide energy for oxidation to occur.

Many products are extremely sensitive to not only the UV portion of the lighting spectrum but also to light energy from certain portions of the visible spectral region. Yellow and green wavelengths predominate in everyday bright fluorescent lighting and cause color distortions.

Superior Lighting Solutions

Since shoppers generally prefer food items that look the freshest and most natural, and expect their purchases to retain their fresh food flavors and appearance for a reasonable time at home in the refrigerator, retailers should install Promolux lighting as part of their ongoing food safety strategy.

Promolux full balanced spectrum lighting is designed for true color definition and to maximize the shelf life of foods displayed for sale. Promolux is engineered to reduce the rates of growth of microbial pathogens by controlling levels of both visible and invisible emissions, to display fresh foods with their full balanced range of color, and to extend the shelf life of all perishable foods.