Community | July 02, 2012 | 14 comments

Why supermarket tomatoes tend to taste bland

source: http://www.latimes.com/news/science/la-sci-tomato-taste-20120630,0,4449608.story

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Radical_Centrist

http://www.latimes.com/news/science/la-sci-tomato-taste-20120630,0,44...

The mass-produced tomatoes we buy at the grocery store tend to taste more like cardboard than fruit. Now researchers have discovered one reason why: a genetic mutation, common in store-bought tomatoes, that reduces the amount of sugar and other tasty compounds in the fruit.

For the last 70-odd years, tomato breeders have been selecting for fruits that are uniform in color. Consumers prefer those tomatoes over ones with splotches, and the uniformity makes it easier for producers to know when it's time to harvest.

But the new study, published this week in Science, found that the mutation that leads to the uniform appearance of most store-bought tomatoes has an unintended consequence: It disrupts the production of a protein responsible for the fruit's production of sugar.

Mass-produced tomato varieties carrying this genetic change are light green all over before they ripen. Tomatoes without the mutation — including heirloom and most small-farm tomatoes — have dark-green tops before they ripen. There is also a significant difference in flavor between the two types of tomatoes, but researchers had not previously known the two traits had the same root cause.

The study authors set out to pin down the genetic change that makes tomatoes lose their dark-green top. They focused their attention on two genes — GLK1 and GLK2 — both known to be crucial for harvesting energy from sunlight in plant leaves.

They found that GLK2 is active in fruit as well as leaves — but that in uniformly colored tomatoes, it is inactivated.

Adding back an active GLK2 gene to bland, commercial-style tomatoes through genetic engineering created tomatoes that had the heirloom-style dark-green hue. The darker green comes from greater numbers of structures called chloroplasts that harvest energy from sunlight.

The harvested energy is stored as starches, which are converted to sugars when the tomatoes ripen.

The vast majority — 70% to 80% — of the sugar in tomatoes travels to the fruit from the leaves of the plant. But the remaining amount of sugar is produced in the fruit. This contribution is largely wiped out in uniform, commercial-style tomatoes — and thus they won't be as sweet.

Study coauthor Ann Powell, a biochemist at UC Davis, noted that this isn't the only cause of the uninspiring flavor of modern mass-produced tomato varieties, but said it definitely contributes.

Though the scientists were not even able to taste their own creation because ofU.S. Department of Agricultureregulations, they could show through chemical tests that the sugar levels were 40% higher in their engineered fruit. Chemicals called carotenoids, which also significantly contribute to flavor, were more than 20% higher.

Full Story: http://www.latimes.com/news/science/la-sci-tomato-taste-20120630,0,4449608.story
  1. groups:
    Community,   Green,   Sustainable Agriculture
  2. tags:
    GMOs
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14 comments // Why supermarket tomatoes tend to taste bland

  • ankab
  • Mark701
  • Radical_Centrist
  • ampersand
    • +1
      ampersand  

    • If you needed any other impetus to getting active about insuring the origin and quality of your food, the recent WTO case won by Mexico and China against the US under the current trade rules will now eliminate any reference to the country of origin for your produce.
      Get used to the taste of heavy metals in your ketchup, my brother.

    • 11 months ago
  • mrpuma2u
  • cpad
    • +7
      cpad  

    • This is happening to all produce. This is a big reason why people are no longer attracted to healthy food. Supermarket fruits and veggies taste like crap

      Once you've tasted real fruit and vegetables, it ruins you for the garbage they sell in stores.

      When our grandchildren are visiting, they love to eat straight from the garden.

      Our 6-year-old granddaughter who is currently visiting us goes straight to the garden ever morning to pick her breakfast strawberries. Every evening, she picks her own salad to have with dinner - various types of lettuce, spinach, green onions, chives, chive blossons, dill, mint and radish. The veggies are so full of flavor that nobody bothers with dressing.

      I'm convinced that if every child was raised with access to fresh food, we wouldn't have an obesity epidemic.

    • 11 months ago
  • gump
    • +2
      gump  
    • cpad:

      Hey O, Always good to see you. I used to grow some tomatoes every year. The fruit in the stores is sad sad stuff compared to tomatoes ripened on the vine. Especially compared to heirloom varieties. One of the best ways to eat tomatoes is the paste anyway .Because the molecules that are the red color combine during the evaporation process to form a super food that helps the human body do many good things 24 / 7. Like prevent and control some types of cancer. I tell people "Eat ketsup!!!" Then I say "Just a bottle a day keeps the doctor away". When they hear "a bottle a day" it cracks them up. Lots of fun in the check out line. That process with the ethelene to "ripen" the green tomatoes while in transit was suposedly discovered in a warehouse near Safford Arizona . Just a ways off to the east of here. Hundred miles or so. They are still just green tomatoes as far as I am concerned. Wish I was farming. Still have two old tractors in the front yard. They need some rehab to get running again. Nutrition can be the best medicine sometimes.

    • 11 months ago
  • cpad
    • +3
      cpad  
    • gump:

      Hi gump - likewise :)
      Yes, tomatoes are a super-food, packed with immune system boosters.
      I'd like to see every school teach basic gardening - have a community plot and let all students learn how to grow their own food.

      With children, all the blah blah blah about nutrition goes in one ear and out the other. But give them something delicious to eat and they sure understand that.

    • 11 months ago
  • gump
  • ampersand
    • +1
      ampersand  
    • cpad:

      So right. If the taste buds aren't poisoned with daily applications of junk food kids (and adults) will get healthy. If they can get a steady supply of good fresh food they can stay that way. When I'm away from my home I've begun to miss my garden more than anything.

    • 11 months ago
  • HarukoHaruhara
  • PressCore
    • +4
      PressCore  

    • Adding to this disruption though is nearly standard procedure
      to grow tomatoes inorganicly. in soil ruined by petrochemical
      based fertilizers. These artificial fertiliers have a higher content
      of the main chemicals tomato plants need to grow in. But they
      destroy the soil's natural composition of insects, worms, microbes
      their waste, etc. This makes new plantings of tomato seeds
      dependent on these petrochemica;l fertilizers. One of the main
      down sides of growing tomatoes or any other food plant by
      the Corporate farming method is that it robs the plant's ability
      to produce the many different enzymes in the proper numbers
      it needs to grow & ripen naturaly in Sunlight. I don't doubt in
      the least the veracity of this article. I'm only adding it's these
      proteinaceous substances ( enzymes ) that cause the hard, green,
      starchy tomatoes to turn into into soft, red, sugary tomatoes.

      All types of organicly grown tomatoes will invariably taste mildly
      acidic, yet sweet if they're ripe. They belong to the berry family
      of fruits. Yet like beans they're arbitrarily typed as vegetables
      instead of fruits. But yes, they're supposed to ripen and taste
      sweet when they do. They taste like wet cardboard because the
      Corporations mucked with them, because they lack necessary
      enzymes also. These amylase enzymes like the kind we have
      in our saliva are what make us healthy too. Idealy, any person
      of any age has optimum health when they have an enzyme to
      antibody ratio of 30. One is near death if their enzyme to antibody
      count is 22. Life exists only within parameters. I got that from an
      Australian doctor studying Japanese health from Tony Brown's
      Journal televised on WCNY circa the mid 1990s. Article voted way up..

    • 11 months ago
  • gump
  • PressCore

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