Curious Cook

Back into the garden

 

Digging up a long-neglected corner of my San Francisco garden a few weeks ago, I came across what look like the skeleton bulbs of garlic or some other lily relative, the skins and flesh gone, only the reinforcing cellulose fibers left behind.

They reminded me of a garden find I made one spring about twenty years ago, after I'd grown a couple of crazily prolific purple tomatillo plants. The winter had had its slow way with some stray tomatillos, etching away all but the veins of their papery outer husks and in some cases the flesh within, leaving just the seeds to rattle around. The remnants made an absorbing anatomy lesson, an image of the passing pleasures and durable purpose of fruits.

I've been neglecting this blog as I have my garden, and for many of the same reasons. But I'm starting to work both again. There's plenty to unearth and cultivate and share.

 

Curious Cook in the New York Times: Slowing the spoilage of fresh berries

In today's Curious Cook column I write about a simple hot-water treatment that slows the spoilage of berries fresh from the market.

The treatment goes back to research done at the Fresno, California station of the USDA in the 1960s. It's been widely studied since then as an option for fruit producers and distributors, but no one seems to have told consumers about it.

The term "thermotherapy" appears in Portuguese and English in a paper from Brazil about the fruits of Spondias mombin, a mango and cashew relative known by many names, including "hog plum."

Curious Cook in the New York Times: Two-tone persimmon pudding

The chemistry of dark, rich persimmon pudding is the subject of my column in the New York Times this week. There's also a recipe for a pudding with two very different colors and flavors.

Curious Cook in the New York Times: Organic produce and yak cheese

In today's Curious Cook column I write about nutritional claims made for organic fruits and vegetables and for yak cheese made in Nepal.

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 Benbrook, C. et al. New Evidence Confirms the Nutritional Superiority of Plant-based Organic Foods. The Organic Center, March 2008.

http://www.organic-center.org/science.nutri.php?action=view&report_id=126

 

Or-Rashid, M.M. et al. Fatty acid composition of yak (Bos grunniens) cheese including conjugated linoleic acid and trans-18:1 fatty acids. J. Agricultural and Food Chemistry 2008, 56: 1654-60. http://dx.doi.org/10.1021/jf0725225

 

Curious Cook in the New York Times: Wild and crazy apples

In the November 21st issue of the New York Times, I write about rare and wild apples, and apples of the future.

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New developments in tomato flavor, part 2: How about some lemon basil in that tomato?

The second of two recent studies of tomato flavor involves genetic engineering, and offers a scent of tomorrow's tomatoes. 

A group of plant scientists in Israel and at Rutgers and the University of Michigan reported their success in transferring a gene from the basil plant into tomato plants. This particular gene diverts molecules in the pathway toward becoming the red pigment lycopene, and sends them instead onto the pathway that generates aroma molecules. The engineered tomato plants produced fruits that were paler than usual, but also had a stronger aroma and smelled distinctly of perfume, rose, geranium, and lemongrass. More than half of a panel of taste testers preferred the engineered tomato to its unengineered parent. 

This experiment may be a harbinger of things to come, a new era of plant modification in which flavor combinations once created by cooks will be re-created--or precreated--by breeders in the plants themselves. 

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Davidovich-Rikanati, R. et al., Enrichment of tomato flavor by diversion of the early plastidial terpenoid pathway. Nature Biotechnology 2007, online publication 24 June.

doi:10.1038/nbt1312

New developments in tomato flavor, part 1: Save the seeds

Two interesting studies of tomato flavor have appeared in the last month. One originated in the kitchen and may immediately change the way you taste and use tomatoes. The other involves genetic engineering, and offers a scent of tomorrow's tomatoes. Here's the first; check back in a few days for the second.

Olive oil pungency and bitterness

Here are a couple of interesting details to add to the story of olive oil's back-of-the-throat, peppery pungency.

In 2003, a research group at Unilever reported on the sensory effects of several of the phenolic compounds found in olive oil, including the cough-inducing substance later named oleocanthal. Oleuropein, the phenolic compound that makes the fruit of the olive bitter, is water-soluble rather than fat-soluble, so it doesn't get transferred into the oil when the fruit is pressed. But a number of oleuropein relatives do end up in the oil, and the Unilever researchers tasted them in pure form. They found these compounds to contribute mainly bitterness and drying astringency, along with some numbing, cooling, sour, salty, and tingling sensations. Relatives of pungent oleocanthal also taste somewhat astringent and bitter. So an oil rich in phenolics can have a very complex taste and mouthfeel indeed.

Other studies have found that heating olive oil reduces the levels of most phenolic compounds. And pepperiness gradually fades as an oil ages. The balance of flavors in an excellent olive oil is thus temporary and so especially worth savoring when you find it. The deterioration of olive oil is slowed by keeping it cool and protected from light.

Salting tomatoes in the greenhouse

Tomato lovers know that a sprinkling of salt enhances the flavor of even the best field-ripened specimen. Some recent news that bodes well for improved flavor in greenhouse tomatoes: you can enhance tomato flavor by salting the plant as the fruit grows! At the Institute of Vegetable Science in Freising, German scientists grew hydroponic tomatoes in a solution that was 0.1% sodium chloride, about one-thirtieth the salinity of seawater. The plants produced fruits with significantly higher levels of flavorful organic acids and sugars, and as much as a third more vitamin C and beta-carotene (the precursor to vitamin A) and the antioxidant red pigment lycopene. The researchers don’t say whether the tomatoes were saltier than usual. They were smaller, so salting the growing medium may be the hydroponic equivalent of dry-farming, which restricts the availability of water to the plant and the dilution of flavor and nutrients.

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Krauss, S. et al. The Influence of Different Electrical Conductivity Values in a Simplified Recirculating Soilless System on Inner and Outer Fruit Quality Characteristics of Tomato. J. Agric. Food Chem., 2006, 441 -448. http://dx.doi.org/10.1021/jf051930a

Citrus news: varieties and powers

The citrus family is hard to keep up with. Its few well-defined species happily hybridize with each other, so they've produced many not-so-well-defined species and varieties, only a few of which we see outside of Asia. And citrus chemistry is highly variable as well, which is why oranges, lemons, limes, and grapefruits share a common character but are so distinctive. A handful of publications over the last year suggests how many varieties we have yet to taste, what useful substances they contain, and how they can affect other ingredients in the kitchen.