
Calcium Bath Keeps Melons Fresh LongerBy Ben Hardin February 24, 1999Dunking melons in special calcium solution right after harvest prolongs
fruit freshness up to two weeks beyond the normal shelf life of seven to 12
days, Agricultural Research Servicescientists report. Longer melon shelf life is good news for consumers, given that per capita
melon consumption in the U.S. reached new highs in the 1990's, thanks largely
to sweeter, more nutritious varieties. Now the calcium treatment may further
boost melon consumption by paving the way for extensive marketing of
vine-ripened fruit. Aging melons--especially the tissue associated with the rind--need calcium
to maintain firmness that protects against spoilage. But calcium in the tissue
becomes depleted as it steadily migrates to the seeds. ARS plant physiologists in Weslaco and Houston, Texas, first studied
greenhouse-grown melons to find concentrations of an amino acid-calcium chelate
solution that might curb the migration loss without harming the fruit. Then, in
experiments begun last spring, they submerged field-grown melons for 20 minutes
in solutions of up to 4 grams of calcium per liter. With technology for extending melons shelf life, growers of recently
developed hybrid honeydews may find marketing of vine-ripened fruit a more
attractive option partly because it will become easier to comply with a federal
harvesting law. It stipulates that melons destined for interstate commerce can
be harvested when 9 percent of the fruit consists of solids that can be
dissolved in water. When ripe hybrid melons detach themselves from the vine,
their soluble solids contents typically range from 12 to 15 percent, almost
totally in the form of sugars. An article about the calcium treatment appears in the February issue of
Agricultural Researchmagazine. The article also is online at: http://www.ars.usda.gov/is/AR/archive/feb99/melon0299.htm ARS is the chief research agency of the U.S.
Department of Agriculture. Scientific contact: Gene E. Lester, ARS Crop Quality and Fruit Insect
Research Unit, Weslaco, Texas; phone (956) 565-2647, fax (956) 565-6652,
[email protected]; and
Michael A.
Grusak, ARS Childrens Nutrition
Research Center, Houston, Texas; phone (713) 798-7044, fax (713) 798-7078,
[email protected]. U.S. Department of Agriculture | |