Helpful person wrote:
> On Jun 29, 3:30 pm, (Victor Sack) wrote:
>> Flavor Is Price of Scarlet Hue of Tomatoes, Study Finds
>> By GINA KOLATA
>> International Herald Tribune
>>
>> Plant geneticists say they have discovered an answer to a near-universal
>> question: Why are tomatoes usually so tasteless?
>>
>> Yes, they are often picked green and shipped long distances. Often they
>> are refrigerated, which destroys their flavor and texture. But now
>> researchers have discovered a genetic reason that diminishes a tomato's
>> flavor even if the fruit is picked ripe and coddled.
>>
>> The unexpected culprit is a gene mutation that occurred by chance and
>> that was discovered by tomato breeders. It was deliberately bred into
>> almost all tomatoes because it conferred an advantage: It made them a
>> uniform luscious scarlet when ripe.
>>
>> Now, in a paper published in the journal Science, researchers report
>> that the very gene that was inactivated by that mutation plays an
>> important role in producing the sugar and aromas that are the essence of
>> a fragrant, flavorful tomato. And these findings provide a road map for
>> plant breeders to make better-tasting, evenly red tomatoes.
>>
>> The discovery "is one piece of the puzzle about why the modern tomato
>> stinks," said Harry Klee, a tomato researcher at the University of
>> Florida in Gainesville who was not involved in the research. "That
>> mutation has been introduced into almost all modern tomatoes. Now we can
>> say that in trying to make the fruit prettier, they reduced some of the
>> important compounds that are linked to flavor."
>>
>> The mutation's effect was a real surprise, said James J. Giovannoni of
>> the United States Department of Agriculture Research Service, an author
>> of the paper. He called the wide adoption of tomatoes that ripen
>> uniformly "a story of unintended consequences."
>>
>> Breeders stumbled upon the variety about 70 years ago and saw commercial
>> potential. Consumers like tomatoes that are red all over, but ripe
>> tomatoes normally had a ring of green, yellow or white at the stem end.
>> Producers of tomatoes used in tomato sauce or ketchup also benefited.
>> Growers harvest this crop all at once, Dr. Giovannoni said, and "with
>> the uniform ripening gene, it is easier to determine when the tomatoes
>> are ripe."
>>
>> Then, about 10 years ago, Ann Powell, a plant biochemist at the
>> University of California, Davis, happened on a puzzle that led to the
>> new discovery. Dr. Powell, a lead author of the Science paper, was
>> studying weed genes. Her colleagues had put those genes into tomato
>> plants, which are, she said, the lab rats of the plant world. To Dr.
>> Powell's surprise, tomatoes with the genes turned the dark green of a
>> sweet pepper before they ripened, rather than the insipid pale green of
>> most tomatoes today.
>>
>> "That got me thinking," Dr. Powell said. "Why do fruits bother being
>> green in the first place?" The green is from chloroplasts,
>> self-contained energy factories in plant cells, where photosynthesis
>> takes place. The end result is sugar, which plants use for food. And,
>> Dr. Powell said, the prevailing wisdom said sugar travels from a plant's
>> leaves to its fruit. So chloroplasts in tomato fruit seemed
>> inconsequential.
>>
>> Still, she said, the thought of dark green tomatoes "kind of bugged me."
>> Why weren't the leaves dark green, too?
>>
>> About a year ago, she and her colleagues, including Dr. Giovannoni,
>> decided to investigate. The weed genes, they found, replaced a disabled
>> gene in a tomato's fruit but not in its leaves. With the weed genes, the
>> tomatoes turned dark green.
>>
>> The reason the tomatoes had been light green was that they had the
>> uniform ripening mutation, which set up a sort of chain reaction. The
>> mutation not only made tomatoes turn uniformly green and then red, but
>> also disabled genes involved in ripening. Among them are genes that
>> allow the fruit to make some of its own sugar instead of getting it only
>> from leaves. Others increase the amount of carotenoids, which give
>> tomatoes a full red color and, it is thought, are involved in flavor.
>>
>> To test their discovery, the researchers used genetic engineering to
>> turn on the disabled genes while leaving the uniform ripening trait
>> alone. The fruit was evenly dark green and then red and had 20 percent
>> more sugar and 20 to 30 percent more carotenoids when ripe.
>>
>> But were the genetically engineered tomatoes more flavorful? Because
>> Department of Agriculture regulations forbid the consumption of
>> experimental produce, no one tasted them.
>>
>> And, Dr. Giovannoni says, do not look for those genetically engineered
>> tomatoes at the grocery store. Producers would not dare to make such a
>> tomato for fear that consumers would reject it.
>>
>> But, Dr. Powell said, there is a way around the issue. Heirloom tomatoes
>> and many wild species do not have the uniform ripening mutation. "The
>> idea is to get the vegetable seed industry interested," Dr. Powell said.
>
> The above research is all very well except that the loss of flavor in
> tomatoes is largely due to the lower acid content of the modern
> fruits. Tomatoes from 40 years ago had an acidic tang to them which
> considerably added to the flavor.
>
> If one wants sweet tomatoes, try the yellow ones. They are lower in
> acid and higher in sugar.


The lack of acid is exactly why I like the green tomatoes--like
green zebra. Some years ago, I got and rated all of the plethora
of heirloom tomatoes that I could find locally. I do hope I can
find my notes--and that I didn't just annotate my printout.

--
Jean B.