The current issue of a glossy, Southern-California-coast lifestyle magazine presented a dubious fact about tomatoes:
“…greenhouse varieties [of tomatoes] have only half the vitamin C of tomatoes ripened outdoors.”
Detecting an environmentally correct (EC) slant to a commonly known commodity, I set about validating the statement. Why? Because the statement threw an unfair, if not incorrect, shot at greenhouse-grown tomatoes. This isn’t uncommon, given the proclivity to ‘clean’ and ‘natural’ in this state.
The research literature on tomatoes is huge. So is the literature on nutritional values of foods. Keywords ‘tomatoes’ and ‘vitamin C’ yielded search results too big to handle, so I relied on the top-most references. Google says they’re most relevant. Right?
Gahler et al (J. Agric. Food Chem. 51 (2003), pp. 7962-68) published their tomato research. They said, and I quote:
“The phenolic content of tomatoes is significantly affected by the spectral quality of ambient solar UV radiation available.”
This led me to believe the glossy magazine statement was right. But wait!
‘Phenolic content’ means certain chemical constituents of tomatoes. I won’t go into the chemistry of phenols right here, but suffice it to say this compound group contains great antioxidants. Those are compounds found in foods that reduce free-radical production, slow aging processes, keep you young, healthy, fit, yada, yada. The trouble is vitamin C isn’t a phenol.
‘Spectral quality of ambient solar UV radiation’ means the kind of light rays hitting the tomatoes that day. UV-A and UV-B are but two different ultraviolet wavelengths coming along with sunlight…and the unreported heat of the day and CO2 content of the air. Neither temperature nor carbon dioxide content were controlled.
And, of course, ‘significantly affected’ led me to believe it meant affected in a good way, although I jumped to that conclusion myself.
My naturally skeptical nature, however, grew doubts about the claim. Research in China produced a publication entitled “Combined effects of enhanced ultraviolet-B radiation and doubled CO2 concentration on growth, fruit quality and yield on tomato in winter plastic greenhouse.”
It reported what I suspected: that the tomato story isn’t that simple. Thank goodness somebody translated it from Chinese. Somebody should have shortened the title.
The Chinese research directly linked enhanced vitamin C concentration to tomatoes grown in greenhouses AND to increased CO2 content in the air. (Recall, CO2 is that environmentally incorrect gas we breathe out, the plants breathe in, and AB32 declared a pollutant.)
This tells me my suspicions are right. The glossy Southern California coast magazine cherry-picked the facts to make its environmentally correct point.
This tells me to consider the source, then come to my own conclusions about everything from global warming to tomatoes.
Or is it, ahem, toe-MAH-toes?