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Two commercial blueberry varieties produced in Florida hold up well
under irradiation, a treatment that could replace methyl bromide, now used
to rid the fruit of quarantine pests. Methyl bromide is a chemical fumigant
that is scheduled to be banned in the United States in 2001. ARS scientists
subjected Climax and Sharpblue blueberries to low-dose irradiation with
only minor effects that should not affect consumer acceptance. Blueberries
shipped to some U.S. and export markets must be certified free of certain
quarantine pests. Currently, methyl bromide is the only approved quarantine
treatment for blueberries against the apple maggot, blueberry maggot and
plum curculio.
U.S.
Horticultural Research Laboratory, Orlando, FL
William R. Miller/Roy E. McDonald, (407) 897-7309
A newly discovered natural compound in tomatoes is important to the fruit's
flavor, ARS researchers have learned. This information can be useful
to tomato breeders and processors. The compound, furaneol (pronounced fur-ANN-ee-ohl),
is the latest of 40 tomato compounds discovered by an ARS research team
over the past several decades. The scientists rank furaneol as among the
ten most important compounds for tomato flavor. Now, breeders can check
new tomato types to make sure the fruit contains this compound. Plus, processors
can monitor paste, salsa and other products and add back any furaneol lost
in processing the tomatoes.
Western Regional Research Center, Albany, CA
Ronald G. Buttery, (510) 559-5667
Hawaiian growers now have a practical method for protecting the quality
of Sharwil avocados that undergo a required, newly approved anti-fruit-fly
treatment before being shipped to mainland markets. Any of four approved
regimens of chilling--to freezing or near-freezing temperatures--will ensure
that the avocados won't harbor live Mediterranean or oriental fruit flies
or melon flies. To prevent these chill treatments from blackening the thin,
bright green skins of the avocados--and making them unmarketable--ARS researchers
recommend two simple steps: Before chilling, heat the avocados for eight
to 12 hours in a room that's kept at 98.6 to 100.4 degrees F, then cool
them for four hours at 68 to 73 degrees F. ARS tests with 8,000 Sharwils
showed the process won't harm the fruit's rich, buttery taste and creamy
texture. If live stowaway fruit flies were to reach the continental United
States, they could thrive on many fruit and vegetable crops in warm-weather
states such as California, Florida and Texas.
Tropical Fruit and Vegetable Research Laboratory, Hilo, HI
Harvey T. Chan, Jr., (808) 959-4343
Government raisin inspectors could soon have a new, more reliable tool
from ARS for evaluating fruit quality. Raisins are graded on visual
characteristics like plumpness, color and wrinkle depth or by a mechanical
sorter that separates heavy from light fruit. The new method uses near infrared,
or NIR, a form of electromagnetic radiation like light and X-rays. This
provides a numeric measure of quality that should improve raisin grading.
USDA's Agricultural Marketing Service is testing the system and may use
it to evaluate about 400,000 tons of fruit annually. When an object is exposed
to NIR--or any type of electromagnetic radiation--it absorbs some energy,
and either reflects or lets the rest pass through. Light or other radiation
that passes through or reflects from raisins produces a spectrum that can
be measured. ARS invented the technology more than 30 years ago, but until
now it hasn't been applied to raisins. An ARS scientist discovered that
high-quality raisins produce a spectrum different from that of low-quality
raisins. The difference compares well with visual evaluations. Once calibrated,
the NIR device can simultaneously measure many characteristics including
acidity and water and sugar content.
Process Chemistry and Engineering Research Unit, Albany, CA
Charles C. Huxsoll, (510) 559-5861
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