There's Bacteriophage in my Bologna

Listeria is a bacterial contaminant of food and while infection is rare, it has a higher mortality rate than Salmonella. Infection may be rare, but the bacteria itself isn't and it can grow at low temperatures, meaning even when refrigerated Listeria can multiply on contaminated food. Of particular concern are foods that aren't cooked or reheated before eating - like the bologna or deli-sliced ham on your sandwich at lunch. Two recent scares at New Zealand hospitals have lead to quarantine of certain ready-to-eat foods after positive Listeria tests as a precautionary measure.

But if Listeria is everywhere and it persists under normal food storage conditions, why aren't infections more common? Well, for one thing, companies do their utmost to eliminate bacterial growth niches in their processing plants - especially after a "kill" step (eg. cooking) - by sanitary design (eliminating nooks and crannies that are difficult to clean) and proper cleaning, followed by other quality control testing. In 2006 (old news, I know), the FDA approved another tool for use in an anti-Listeria arsenal: bacteriophage.

Bacteriophage are bacteriolytic viruses and have a history of use as an antibiotic in the Soviet Union and Eastern Europe. Bacteriophage is the bane of some food making (and other) processes - those based on bacterial fermentation, such as yogurt production. For Listeria management it was approved and recognized as a safe food additive by the FDA in August, 2006. The phage used is a mix of 6 different forms used to target different Listeria strains and to minimize development of resistance. The phages themselves are grown in Listeria and purified before being applied just prior to packaging. The FDA has a FAQ about the bacteriophage additive. (Unfortunately I couldn't find any information about phage use in Canadian food manufacturing, or if there was an uproar in the US when the decision was made) This decision opened the door for other phage uses in the food industry, such as controlling E. coli or Salmonella in a similar way. The designation as 'safe' may also help resurrect the idea of using bacteriophages as antibiotics, particularly to combat emerging superbugs (MRSA).

So there you have it - that turkey sandwich you had for lunch may be a turkey and phage sandwich, so keep it away from your probiotic yogurt.

Tannin-rich foods pt. 2: Wine

Wine, particularly red wines, can be tannin-rich. The tannins in wine are often blamed for red wine headache, and impart a dry bitterness and distinctive taste. The tannins come mainly from skin, seeds and stems present during the fermentation process (which is why red wines tend to be more tannin heavy) but can also be imparted from oak barrels that are often used for storage. Anti-oxidant tannins also play an important role in the aging process - as a wine ages, the tannins precipitate out reducing the harshness of the wine. Because of this, tannin-rich wines benefit more from the aging process than those with a lower tannin content.

Now, I don't have time to wait around several years for my wine to age properly. That's why I drink beer. But if you love wine and are impatient here is the product for you. The Perfect Sommelier is essentially a powerful magnet. Place a bottle on the magnetic coaster, and replace the cork with the magnetic cap - wait 15-30 minutes and presto! your wine tastes as though it's been aged for years. (This is not unlike the wine clip which claims to do the same thing, only faster!) Both products have 'scientific'" explanations for how they work - something about using the magnets to align polar tannin molecules - and oodles of testimonials. I'm not ready to cry 'quack' yet since the nuances of wine taste are a difficult to measure and any such test would be subjective, but I don't think I buy it. Of course, my unrefined palate and I are skeptical of Sideways-esque wine tasting and wines with "the faintest soupçon of asparagus and just a flutter of a nutty Edam cheese." Still, one independent test showed that tasters were unable to tell the difference between treated and untreated wine, or identfied a difference but were wrong half the time (the writer of that critique also has "a background in Electromagentic fields from MIT" and claims there "really is no scientific explanation as to why a little magnet would change the tannic structure or acidic content of a wine").

So, rather than try to make a bad wine good with an overpriced magnet, save your money and invest in learning about real good wines, like with Sommelier for the Nintendo DS. Or just buy a few bottles, do your own tasting, and find ones you like. I'll even help you pick them, but I am NOT drinking any fucking merlot!

Tannin-rich foods: The Acorn

Nuts are tasty. OK, get the puerile laughter out of your system - I'm talking about the food kind: peanuts, hazelnuts, almonds, cashews (before you go botanical on my ass and yell that peanuts aren't nuts, I'm speaking in a culinary sense here. Botanically speaking, almonds, pistachios and many other "nuts" aren't nuts either). But what about that favourite of rodents everywhere: the acorn?

First of all, in a botanical sense, acorns ARE nuts. But why don't we find them alongside pecans, peanuts and brazil nuts when we open a can of mixed nuts? Are they toxic? Do they just taste bad? It being the autumn, with plenty of acorns around, I decided to try them out. First off, this was just an acorn found on the ground and not roasted or salted or otherwise processed. It passed the taste test - it was bitter, but not so vile that it couldn't be eaten. Nor did I get ill - after all, I'm not a horse.

The bitter taste and toxicity to horses is caused by the high levels of tannins, which vary by oak species. These polyphenols have documented anti-carcinogenic, anti-oxidant and anti-microbial properties (review) as well as being nutrient rich. Sounds like it might be worth patenting an acorn extract and selling it as a miracle drug through some sort of pyramid scheme. On the other hand, they are also iron chelators and can interfere with protein digestion in animals that aren't adapted. Plus the overly bitter taste would likely make them unpopular as a snack. Still, acorns were once part of a human (mostly Native American) diet, first being soaked to leach out the tannins followed by grinding into flour.

Some animals that haven't physiologically adapted to tannin rich acorns have adapted in other ways. The most obvious is by selecting acorns that are less tannin-rich. It's been suggested that some animals store their acorn cache in groundwater or other places with water access, allowing the groundwater or natural runoff to leach some of the tannins out making the nut more edible as the winter progresses. One study has shown that Blue Jays, while unadapted to a high tannin diet, consume a large number of acorns in the autumn months with no ill effects because of acorn weevil larvae that live inside the nuts and counteract the effects of tannins on the jay diet.

Canadian Thanksgiving may have passed, but acorns are still plentiful - here are some recipes that incorporate this former traditional food of indigenous North Americans.

The Science of Cooking

In the lab, we're used to following recipes and measuring out reagents with microlitre precision. Yet these skills seem to rarely transfer well to the kitchen. This is doubly odd, considering the amount of science that can be found there. Many people probably know that baking powder is used, like yeast, as a leavening agent (baking powder is a mixture of sodium bicarbonate and an acid salt which react to create carbon dioxide when mixed with water). Fewer will be familiar with the Maillard reaction, the chemical process by which many foods brown when cooking.

Recently, some scientists (and chefs) have been making a push to bring more science into the kitchen, and the result is "molecular gastronomy". Chemist Hervé This (pictured) and physicist Nicholas Kurti coined the term in the late 80s/early 90s, and This is the first (and only) person to hold a Ph.D. in that discipline. His ongoing education is spent collecting, testing and explaining what he dubs 'cooking precisions', various "rules" of the kitchen ranging from recipe instructions (eg. when making a souffle, add the eggs 2 at a time), to anectodal methodology (eg. cut the head off a roast pig immediately when removed from the oven to ensure a more crispy skin), to the absurd (eg. women having their period cannot successfully make mayonnaise). An essay by This on the history and nature of molecular gastronomy can be read here [pdf]. (For the record, the first 2 'precisions' above hold true, but the third is false). Hervé This has also done extensive work with emulsions and foams, developing a system of equations for making them by reducing them to their basic components. It's in this way that he was able to make 24 litres of mayonnaise from a single egg yolk. His equations for foams have paved the way for innumerable inventive sauces and mousses including, but not limited to his famous chocolate chantilly.

A more ovbious example of his scientific leanings is his discovery of the perfect way to cook an egg. The traditional 10-minute boil for a hard-boiled egg, leaves the egg tough and rubbery. By considering the varying temperatures at which specific egg proteins denature and coagulate, This determined that 65 degrees Celsius produces an egg with a custardy white and a soft orange yolk. Just 2 degrees higher and the yolk begins to set, becoming malleable in the hand but still not the grainy-textured yolk of a 10-minute egg. And it's not the time of cooking that matters, it's the temperature. These eggs can be cooked at 65 degrees overnight with the same result. (For those worried about salmonella, it can't survive for more than a few minutes at 60 degrees) Ovalbumin, the most abundant egg white protein, coagulates at around 84oC which is why a boiled egg becomes rubbery. While his work of this nature isn't found in your traditional scientific journal, he does maintain a lab and some of his work can be found on Pubmed (I recommend the Nature Materials commentary if you have access for a good overview of This' work).

Molecular gastronomy is taking the world by storm, combining the study of food and cooking that Hervé This pioneered with the use of advanced technologies. Some of the top restaurants in the world specialize in this style, inventing new flavour combinations (white chocolate and caviar?) and methods of preparation. Chefs of this nature don't shy away from using chemical ingredients you would only find on a candy-bar wrapper, like polysorbate-60 as an emulsifier or chemical thickeners. This allows them to create interesting new textures without compromising the taste of the food, like creating a parsley sauce by thickening parsely juice rather than mixing chopped parsley with oil. Their method, they would argue, delivers a purer dish. Chemical ingredients aren't the only innovation. Dessicators and vaccuum sealers are the norm in these types of restaurants, with the anti-griddle being one particularly cool tool (pun intended) in use. This piece of gadgetry maintains a surface temperature of -34oC, instantly freezing most foods. Why serve something on an olive oil flavoured cracker, when you can serve it on a frozen disk of pure olive oil itself? And with these innovations, the line between kitchen and laboratory becomes more obscured.