Curious Cook

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

Progress in sparkling wines: bubbles and flow

A progress report from Gérard Liger-Belair, the world authority on wine bubbles, and his quest to define the ideal glass for enjoying the effervescence of champagne. Bubbling really stirs up a glass of wine, and if you're going to etch a glass to generate bubbles, you'll need to adjust the pattern to the glass shape.

In the dark: olive oil, milk, butter, and beer

In my last post I mentioned that olive oil is best stored in the dark. The same is true for milk and butter and beer. It's turning out that all these foods are sensitive to light for similar reasons.

Keeping olive oil cool

Refrigeration usually slows the deterioration of our foods by slowing the chemical reactions that cause it. But extra-virgin olive oil turns out to go rancid at about the same rate in the cold as it does at room temperature. Chemists at the University of Udine in Italy found that the benefits of slowed reactions at low temperature are counterbalanced by the gradual crystallization of the more saturated oil molecules. This process leaves the remaining liquid oil with a higher proportion of vulnerable unsaturated fats, and with a smaller proportion of antioxidant substances, which tend to get trapped in the crystals. So oxidation continues at about the same pace despite the low temperature.

There's no need, then, to crowd the fridge with bottles of special olive oil. Just keep them in a cool, dark place. And this is especially true for unopened bottles. Another study from the Universities of Milan and Castilla-La Mancha reports that freshly bottled Italian and Spanish oils high in antioxidants retained much of their antioxidant capacity after as much as 240 days storage at 40 degrees Centigrade, or 104 degrees F. One oil made from the Picual olive even remained fully within the specifications for extra-virgin olive oil.

One other useful fact to be gleaned from the first report: the viscosity of olive oil nearly triples as it cools from room to refrigerator temperature. As many cooks know, you can make a plain vinaigrette very thick and creamy simply by serving it and the salad ice-cold.

Calligaris, S. et al. Influence of crystallization on the oxidative stability of extra virgin olive oil. J. Agric. Food Chem. 2006, 54, 529-35.

Lavelli, V. et al. Effect of storage on secoiridoid and tocopherol contents and antioxidant activity of monovarietal extra virgin olive oils. J. Agric. Food Chem. 2006, 54, 3002-07.

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.

Trying to Clear Absinthe’s Reputation

READERS of Ernest Hemingway know “Death in the Afternoon” as a book about bullfighting. But to drinkers with a taste for obscure booze, it is also a cocktail that Hemingway contributed to a 1935 collection of celebrity recipes. His directions: “Pour one jigger absinthe into a Champagne glass. Add iced Champagne until it attains the proper opalescent milkiness. Drink three to five of these slowly.”

Curious Cook in the New York Times: Absinthe and champagne

In today's dining section I write about a recent analysis of the fact and fiction surrounding absinthe and its distinguishing ingredient, wormwood. And about the latest from the bubble laboratory of Gérard Liger-Belair, deep in champagne country. And what happens when you mix absinthe and champagne.

Anyone who enjoys sparkling wine will love Professor Liger-Belair's informative and poetic book Uncorked: The Science of Champagne, published by Princeton University Press in 2004.

Lachenmeier, D.W. et al. Absinthe: a review. Critical Reviews in Food Science and Nutrition, 2006, 46: 365-77.

Liger-Belair, G. et al. Modeling the kinetics of bubble nucleation in champagne and carbonated beverages. J. Physical Chem. B 2006, 110: 21145-51.

Liger-Belair, G. Et al. Champagne experiences various rhythmical bubbling regines in a flute. J. Agric. Food Chem. 2006, 54: 6989-6994.