July 05, 2007
Organic Tomatoes Contain More Flavonoids
An unsurprising result:
According to the new findings, levels of the flavonoids quercetin and kaempferol were found to be on average 79 and 97 per cent higher, respectively, in organic tomatoes. Flavonoids such as these are known antioxidants and have been linked to reduced rates of cardiovascular disease, some forms of cancer and dementia, says Alyson Mitchell, a food chemist who led the research at the University of California, Davis.
The quality of tomatoes varies enormously from pale unmoist tomatoes sold in supermarkets in the winter to the best stuff from sandy acidic soil picked fully ripe in summer. Of course this stuff varies greatly in how much flavonoids it contains.
But the effect of organic farming might not apply to all organically farmed tomatoes.
That meant growers didn't need to use as much compost to keep nitrogen levels high. And without that extra boost of growth-promoting nitrogen, plants seemed to devote more energy to producing flavonoids.
The findings don't necessarily mean that all organic tomatoes would contain more flavonoids, Mitchell stressed, because soils and growing methods on different farms could vary tremendously.
My own experience with garden-grown versus farmed tomatoes is that home grown tomatoes taste much better and look more colorful than most tomatoes sold in stores.. Either soil conditions or types of tomatoes used or the ability to let the tomatoes fully ripen on the vine in gardens might account for the difference. My guess is that the tangier and more colorful tomatoes have more beneficial chemicals.
"Flavonoids are produced as a defence mechanism that can be triggered by nutrient deficiency. The inorganic nitrogen in conventional fertiliser is easily available to plants and so, the team suggests, the lower levels of flavonoids are probably caused by overfertilisation."
It's CRAN for tomatoes. But it has nothing to do with organic methods. The same could be done with any agronomic system by creating and maintaining nutrient deficient soil. Crop volume would fall but so would production costs, and if there is a premium for such produce it might come out even. Or, they might learn how to shock them into deploying defense mechanisms even in fertile soil, or develop varieties that didn't require abuse to produce high flavonoids.
The varieties of tomatoes grown for mechanical harvest are specially developed to be tough. It's one of the instructive stories about the increasing mechanization of crop harvest. There seems to have been some loss of other desirable qualities such as flavor and texture.
Labor for crop harvest is a big issue in ag. The machines aren't yet a good replacement for human pickers. Robotics may solve this problem one day.
Organic farming will probably never be efficient enough to feed a modern civilization, but I believe it's a good idea to grow samples of all our staple crops in environments as close to "wild" as possible so that we will have examples of what the "best outcome" is for each one. We are evolved to eat food as it naturally occurs in the wild. That will always be the healthiest and tastiest. Once we know for sure "this is the best possible tomato", then we can tweak our farming systems to produce that outcome in the most efficient way possible.
"Flavonoids are produced as a defense mechanism that can be triggered by nutrient deficiency."
Removing stress from a living system makes it weak, flabby and bad tasting. Just compare the average beer-drinking, TV-watching modern worlder with a hunter gatherer in his prime. There's a reason predators don't like the taste of modern humans; and it's the same reason garden fruit tastes better than mechanically farmed fruit. We must stimulate our tomatoes to produce the good stuff, and we do that by being "mean" to them.
"Labor for crop harvest is a big issue in ag. The machines aren't yet a good replacement for human pickers. Robotics may solve this problem one day."
Sooner than you think, probably.
Another factor in store bought produce is that much of it is picked before it's ripe to allow for shipping and processing time. That plays a big part of the taste and quality of store bought produce. You can try it out in your own garden too. Pick your tomatoes when it start to redden, put it on the windowsill and let it "finish ripening". When it is ripe, go pick a fresh ripe one and compare the difference in taste and color.