Market Lighting Affects Nutrients

There is a lesson here and it isthat fresh vegetables could profitably it set out in the morning for eveningconsumption to convert as much nutrients as possible.  A little planning perhaps, but there shouldbe little if any deteriation and plausibly a rebound in general vitality.

I suspect that the dark treatmenteven lowers the nutritional value.

Anyway it is something else tofuss over for the foodies.

Market Lighting Affects Nutrients

by Rosalie Marion Bliss

Washington DC (SPX) May 04, 2011

Scientists at the ARS Produce Quality and Safety Laboratory in Beltsville, Maryland,are focusing on ways to keep packaged fresh-cut lettuce andleafy greens safe. Photo by Keith Weller.

http://www.seeddaily.com/reports/Market_Lighting_Affects_Nutrients_999.html

Many people reach toward the back of the fresh-produce shelf to find thefreshest salad greens with the latest expiration dates. But a study led by U.S.Department of Agriculture (USDA) scientists may prompt consumers to insteadlook for packages that receive the greatest exposure to light--usually thosefound closest to the front.

The study was led by postharvest plant physiologist Gene Lester whileat the Agricultural Research Service (ARS) Crop Quality and Fruit InsectsResearch Unit in Weslaco, Texas. ARS is USDA's chief intramural scientificresearch agency.

Lester and colleagues Donald Makus and Mark Hodges found that spinachleaves exposed to continuous light during storage were, overall, morenutritionally dense than leaves exposed to continuous dark. Lester now works atthe ARSFood QualityLaboratory in Beltsville, Md.

For the study, the researchers exposed spinach leaves to light similarto the 24-hour artificial fluorescent light received by spinach in packages locatedat the front of the display case. A second group was enclosed intwo-layer-thick, brown-grocery-bagpaper to represent the "dark treatment."

Both experimental groups were housed in market-type,light-transmissible polymer tubs with snap-tight lids and were kept in walk-instorage chambers at 4 degrees Celsius, the same temperature at which marketscurrently display packaged spinach.The light reaction of photosynthesis is not temperature-dependent and can occurat 4 degrees C in the right type of light.

The researchers found that the continuous light affected the leaves' photosyntheticsystem-resulting in a significant increase in levels of carotenoids andvitamins C, E, K, and B9, or folate.

While the simulated retail light conditions actually helped the storedleaves gain in content of several human-healthy vitamins, some wilting occurredafter three days of storage in flat-leaf spinach, but not crinkled-leaf types.

Results from this work were published in the Journal of Agricultural and FoodChemistry.