Click image for caption and other photo
story to find out more.
Aromatic Compound Deepens Red Coloring in Apples
By Jan Suszkiw
April 30, 2003
Spraying apples with the aromatic
compound methyl jasmonate (MJ) before harvest may offer a new way to improve
the uniformity of the fruit's red color. That's the implication of studies by
Jim Mattheis, an Agricultural Research
Service plant physiologist who is exploring new ways to improve the quality
and marketability of apples, pears and other fruit grown in the Pacific
In jasmine and some other plants, MJ has many functions, including
mobilizing antimicrobial proteins. A sweet, flowery aroma also makes MJ a
popular cosmetics ingredient, and it is classified by the
Food and Drug Administration as a Generally
Recognized As Safe substance.
Starting in 1998, Mattheis followed up on earlier research showing that,
when apples are exposed to light, MJ activates biochemical processes in the
peel that produce anthocyanin pigments. Along with graduate student Dave Rudell
and ARS food technologist Xuetong Fan, Mattheis devised a water-based emulsion
containing 2 percent or less MJ and a surfactant that can be sprayed directly
onto unpicked fruit.
Through lab and orchard trials with Red Delicious, Gala and other varieties,
the team discovered timing is crucial; some apples treated too early in the
season lost their red color by fall harvest. And too much MJ sometimes harmed
the fruit. But at concentrations of 2 percent or less, no adverse effect or
significant change in eating quality was apparent, according to Mattheis, at
ARS' Tree Fruit Research Station in
ARS, on behalf of the U.S. Department of
Agriculture, has applied for patent protection on the MJ apple treatment.
One particular use may be correcting uneven coloring in Fuji apples that have
spent much of their growing season in opaque bags. A more detailed article on
the work is in the May
issue of Agricultural Research magazine.
ARS is USDA's chief scientific research agency.