Friday, 31 October 2014

Jerusalem artichoke – breaking news

So, what’s new in the world of Jerusalem artichoke, I hear you ask.

Well, Helianthus tuberosus has made the headlines on a few occasions recently. The Daily Mail, that repository of informed opinion, for example, reported on the case of Lyndsey Glassett, who returned home after a weekend away and was devastated to find that her Jerusalem artichoke plants had been sprayed and had died. The 67-year old liked to slow-cook the tubers in wine or grate them raw into salads. She watched the CCTV of her garden, and discovered that her sister, who lives across the road from her in Broxbourne, Kent, had done the deed. They have been at loggerheads for several years, apparently, and she accused her of killing the plants out of spite. She claims, rather unconvincingly in my opinion, that she was doing it because they looked like weeds. The case went to court:

It was National Chocolate Day this week, and Glamour magazine (again, not my usual reading I must admit) somehow managed to lump Jerusalem artichoke in with a bunch of ingredients du jour. “Beaming Superfood Cookie…  you won't believe all the other good stuff that's in this sweet treat: applesauce, Beaming Protein with greens (hemp protein, chia seed, yellow pea protein, brown rice protein, maca, mesquite, lucuma, vanilla, Jerusalem artichoke, coconut, sugar, cinnamon, Himalayan pink salt, chlorella, blue green algae, spirulina), coconut sugar, vanilla, sea salt, vegan chocolate chips, and sliced almonds.” It’s pretty unbelievable, I guess, but I did cut-and-paste it, so it must be true. For more healthy chocolate ideas:

Jerusalem artichoke have become a little bit fashionable again in restaurants, after many years of being neglected. This may continue this winter, as they are just coming into season again. For example, writing of a visit to Norse in Harrowgate this week, Elaine Lemm enthuses about “poached baby globe artichoke, pickled pear with Blacksticks blue, chervil root puree and chilled chervil broth as the first dish. For seconds, pan-fried plaice, Scottish mussels, salsify and sea veg with burnt cream and smoked Jerusalem artichoke.”  For more:

My Jerusalem artichoke have grown pretty well this year, but I don’t dig any until they have been subjected to a hard frost. As it has been positively tropical for late October here in Wales, I can’t see them being harvested for a while yet.

My advice when eating them is: a little goes a long way. Don’t overdo it. For a hint why, see my previous blog post on Jerusalem artichoke, which was entitled: ‘Why do Jerusalem artichoke make you fart?’ All is revealed at:

I extracted information for that blog post from a book I wrote, with Prof. Stan Kays from the University of Georgia (USA), called ‘The Biology and Chemistry of Jerusalem artichoke (Helianthus tuberosus)’. This is currently ranked 3,237,947 on the Amazon bestsellers list:

Now, I know that can’t be good, because I get (or don’t get) the royalty cheques. However, I think the price the publishers charge for academic books like this might have a bearing.

Google books do a section for books where you can read selected pages (I don’t remember signing up for that one). Unfortunately, they have not selected any of the racy pages or even any of the interesting pages (the meat of the book concerns the Jerusalem artichoke’s USP – the inulin it lays down instead of starch):

Must sign off on this now, to deal with some 'trick-or-treaters'. Another Jerusalem artichoke news update coming soon, in a couple of years.

Tuesday, 28 October 2014

Personal taste

In recent posts, I have written about the environmental factors that influence how we perceive food and drink.  To complete this mini-strand, I offer a few words on the genetics of taste perception.

Back in 1931, a chemist called Arthur Fox was carelessly working with a powder called phenylthiocarbamide (TCP). His colleague complained that some of the airborne powder tasted bitter, but Fox could not taste anything. Studies to date have confirmed that around 75% of people can taste TCP and 25% cannot. With increasing knowledge of genetics, this ratio strongly suggested that a single dominant gene was involved in TCP perception; though the fact that people vary in their sensitivity to it suggests that other factors are also involved. In 2003, geneticists identified the gene – TAS2R38 – coding for the TCP receptors.

TCP does not occur naturally, so what is the significance of this? The answer was once life or death, of course. The TCP receptors are just part of the structures on the tongue that detect bitter substances. There are now around 30 genes linked to such bitter taste receptors. Your ability to taste TCP is positively correlated with your ability to taste other bitter substances, most significantly toxic compounds in plants that you might want to try eating.

I was reminded of this at Green Man this summer. One of the University Science Department stands in the Einstein’s Garden area of the festival was conducting simple genetic test, including the one for TCP perception.  As on previous occasions, this confirmed that I can taste TCP. Though this leaves a bitter taste in the mouth, it is a good thing (and they did supply sweets afterwards). It means I have a better chance of detecting bitter toxins in my food than people who cannot taste it, or it would if we all still lived in the age before supermarkets.

The genetic component for the perception of the other four basic tastes is thought to be less strong, though recent research has revealed that the perception of sweetness is partly inherited. This research is being done with a view to understanding obesity. Genetics may have little bearing on how we perceive salty and sour, while less is known about unami generally.

There are a number of technical terms to describe medically-related conditions involving taste perception, but these are more linked to environmental factors, particularly the onset of certain diseases, than genetic factors. For example, people can have ageusia (complete loss of taste), hypogeusia (partial loss of taste), dysgeusia (distorted sense of taste) and hypergeusia (abnormally heightened sense of taste). While ill, I have experienced mild versions of a couple of these and it certainly makes you appreciate your food when you recover.

One of the many environmental factors influencing how we perceive taste is aging, with older people often having reduced sensitivity to salty or bitter tastes. Acquired tastes are preferences that develop over time. These can override any genetically determined aversion to bitter or unusual tastes. Coffee, Marmite, broccoli, goat’s cheese and Brains Bitter, for example, are acquired tastes. It all goes to show that taste can be a very personal thing.

See also:
Crossmodal sensory perception

Pete Brown on beer and music

Some archived posts you may be interested in:
Genetics at the National Botanic Gardens of Wales


Raw Vegan Rock and Roll