Of the dozen tomato varieties displayed at Vang Thao's stand last Saturday, one, with purplish black skin over a flaming orange ground color, stood out spectacularly. It's a new variety, Indigo Rose, pigmented by anthocyanins, the same compounds responsible for the dark color in cherries, blood oranges and red cabbages, but not previously significant in cultivated tomatoes.
It's noteworthy not so much because of the flavor — it's nice but not memorable — but because of the potential health benefits, and also just because of its sheer oddity.
Tomatoes generally get pink color from lycopene, orange and yellow from carotenoids, and green from chlorophyll; the dusky purplish brown of tomatoes like Cherokee Purple and Black Prince comes from lycopene combined with pheophytin, a brown pigment derived from chlorophyll. However, in tomatoes as in many plants, anthocyanins are often present in the leaves and stems, where they protect internal cells by blocking harmful ultraviolet light while selectively admitting light vital for photosynthesis.
In addition, several wild species of tomatoes from Chile, Peru and the Galapagos Islands do contain anthocyanins in the fruits, and starting in the 1950s, researchers crossed them with cultivated tomatoes. (There's one excellent older variety, Purple Smudge, that has just a smidgen of anthocyanin; Elser's Country Farm sells an orange-fleshed variant at the Hollywood, Torrance and Redlands markets.)
Jim Myers, professor of horticulture at Oregon State University, used conventional crossing (not genetic modification) of experimental selections to breed the much darker Indigo Rose, which he released this year. Because of its beauty and novelty, it quickly caught on with home gardeners and farmers market growers, including Vang Thao of Fresno, who sells at both Torrance markets and at Santa Monica on Saturdays, and Mark Carpenter of Santa Paula, who is at Santa Monica on Wednesdays and Saturdays.
Anthocyanins are flavorless, although genes linked to their presence can affect taste. Indigo Rose, whose intermediate size makes it a "saladette," in tomato parlance, has a nice balance of sweetness and acidity, and good tomato flavor, although it doesn't compare in richness and complexity with the finest heirlooms such as Black Krim. Its ripeness can be difficult to judge, since the usual visual cues can be masked by purple; skin exposed to the sun tends to be dark and shaded portions reddish orange.
Some studies have claimed that anthocyanins serve as antioxidants that scavenge free radicals, which can cause cancer; lower LDL cholesterol, the type that fosters heart disease; and protect against diabetes. Interestingly, an Oregon State Web page for Indigo Rose says that "some recent research suggests that anthocyanins may not act directly as antioxidants, but may produce health benefits in a more complex manner."
In any case, the anthocyanins in Indigo Rose are just in the skin, not the flesh, so the variety's anthocyanin content is lower than that of many dark fruits such as blackberries and cherries; and since the ruddy pigment is water soluble, it largely disappears when Indigo Rose is cooked.
The plants appear to grow and bear well here, even in the brutal heat of Fresno. Jimmy Williams of Hayground Organic Gardening, who sells out of the plants at the Santa Monica and Hollywood markets whenever he offers them, says they seem exceptionally healthy; but Tim Eckerton, who grows them in more humid conditions in Pennsylvania, says that his plants appear to be susceptible to disease. Since this is a new class of tomato, it may take time for growers to figure out where and how best to grow it and for the public to learn how to use it.
Within two years, Myers plans to introduce new anthocyanin-rich tomato varieties in varying sizes, with improved disease resistance, even better flavor and anthocyanins throughout the flesh, he said by phone. "Our main motive is the health benefits, but aesthetics also plays a role," he added.
Other picks of the week: fresh lima beans from McGrath; fresh garbanzos from K&K Farms; Piel de Sapo ("Papaya") melons and Kyoho grapes from Ha.
The picks Back East
At Southern California farmers markets, we are lucky to have the best year-round selection of produce in the country, which is at its peak in diversity and abundance in midsummer. But there are certain items that we can't find here, and it is these in particular that I search out each year when I revisit the Union Square Greenmarket in New York City.
At the top of the list are gooseberries, a true Old World delicacy, cousins to currants, with somewhat larger, translucent fruit, either green or red. Typically they're a bit tart for most palates for eating fresh and are used for fools, crumbles and preserves, but the red-fruited specimens sold by Locust Grove Fruit Farms at last Wednesday's market had a perfect balance of sweetness and acidity, and exquisitely intense flavor. Why aren't gooseberries grown in California, at least for farmers markets? They should do fine in cooler coastal areas with decent winter chill, like Lompoc.
Tart (a.k.a. sour) cherries are another fruit that's mysteriously missing in the Golden State. They do grow in our cherry districts, aside from the hottest areas; they may not be as productive as in Michigan or the Northwest, but local fruit would meet an eager reception from Mideasterners and Eastern Europeans at our farmers markets. They're intended chiefly for cooking and baking, but the Balatons from Caradonna Farms at the Greenmarket, dark on the inside like the old Morello variety, have a complex, winy flavor that makes them irresistible as dessert fruit too.
Tristar strawberries, small, deep red, and delicate in texture, might strike some Californians as a bit tart, accustomed as we are to our own varieties, which tend to be larger, firmer and lower in acidity. But try a pint of this variety as grown by Franca Tantillo (Berried Treasures) or Rick Bishop (Mountain Sweet Berry Farm) and let your palate become accustomed to this different style of fruit, as your eyes might adapt to different lighting, and you'll taste a richness, concentration and a strawberry jam-like flavor that explains why this variety is emblematic of the Greenmarket.
Despite the ample offerings of our own farmers markets, there remain a few things that the Big Apple has to teach us.