Thursday, August 08, 2013

Potatoes with the Bone in them.

The current trend is that vegetables must be cooked only briefly. They must remain crunchy. A nutritional justification is given for this, but explanations can always be formulated to fit the prevailing belief or fashion. I know that some vitamins and other nutrients are destroyed by boiling, (but how much boiling?) but I understand that others are more easily assimilated when the vegetables are cooked to a greater degree. I must look up the actual, real, scientific evidence for this belief that undercooked is nutritionally better than more cooked. And how much cooking is over-cooking anyway? I routinely overcook vegetables in soup, I think. Does this mean that my vegetable soup is a nutritional wasteland?

Interestingly, even the most fanatical crisp vegetable-lover does not generally want his or her potatoes undercooked. One group in history did choose to have them this way however.

A report in 1809, from King’s County, Ireland, on the potato appeared in An Account of Ireland, Statistical and Political, (1812) by Edward Wakefield.

“Parboiled potatoes are preferable; the laboring poor say they go farthest when the bone is left in them. A man with his wife and four children, from four to fourteen years of age, will eat two stone [28 pounds] of them per day.”

The Irish peasant’s best potatoes went to market, the poor quality ‘lumpers’ were eaten by the family, and they were undercooked because “they stick to our ribs and we can fast longer that way.”

Now I have a burning need to find out about the digestion of cooked versus undercooked potatoes, and the reality of slow digestion versus the perception of slow digestion of the undercooked variety – such is the curse of curiosity.

As always, I value your insights and opinions, so please do comment, and I will endeavor to respond as soon as possible.  In the meanwhile, I give you a most intriguing recipe. Please, someone, explain the name of these delicious-sounding sweet treats.

Lent Potatoes.
Beat three or four ounces of almonds, and three or four bitter, when blanched, putting a little orange-flower water to prevent oiling; add eight ounces of butter, four eggs well beaten and strained, half a glass of raisin wine, and sugar to your taste. Beat all well till quite smooth, and grate in three Savoy biscuits. Make balls of the above with a little flour, the size of a chestnut: throw them into a stew-pan of boiling lard, and boile them of a beautiful yellow brown. Drain them in a sieve.
Serve sweet sauce in a boat, to eat with them.

A New System of Domestic Cookery (1808) by Mrs Rundell.


Beth Elaine said...

They actually may have something there. Leaving pasta al dente supposedly slows digestions, and is less likely to cause a sugar spike.


srhcb said...

More starch leaches from potatoes the longer they're boiled, but I'm not sure how much difference that would make?

"Lent Potatoes" must be a joke; a way to sneak forbidden ingredients into your diet during Lent under the guise of a potato?

Sarah said...

Hello! I love your blog and was hoping you might be able to help me with a culinary history question. On my blog ( we're doing Australia month, and each month I do a post on that country's culinary history. The problem is, most of my usual resources (and personal knowledge) focus on Europe, and sometimes only Medieval Europe. I've read your previous posts on Australia's culinary history (I particularly loved the 1922 menu) and I was wondering if you might be able to point me in the direction of sources that cover the development of Australia's cuisine after its settlement by the British? I know it's one of the most culturally diverse countries in the world, and I'd love some sources that talk about, say, the increasing use of Asian ingredients like curry, or the impact of Polynesian/tropical ingredients. Any suggestions would be much appreciated! Thank you! - Sarah

Mike said...

I agree that the current fashion for cooking vegetables very lightly can border on faddism. It seems to me that some are good cooked "al dente", but others can be good raw as salad, and yet others better with longer cooking. There's no one right way for all vegetables on every occasion.

To be sure some nutrients are easily degraded by prolonged cooking. The most obvious one here is vitamin C. This is also one reason why some vegetables are started in water that is *already* boiling. This makes the cooking quicker. Compare how starchy vegetables, such as potatoes, are usually started in cold water. Protein foods - meat, fish, or eggs - are, of course, never boiled at all but always simmered - even though we colloquially speak of them as "boiled" and this is because since too high heat will degrade the proteins and toughen the food.

(Note also that vegetables that want rapid cooking are usually cooked uncovered. IIRC, a lid will cause acids that are driven off as the food heats up to condense and fall back into the pan where they will help to break down the vitamin C.)

There's a lot of science behind these different cooking strategies - although one supposes that they arose not so much out of explicit scientific knowledge, as out of people understanding practically what worked and what didn't.

One advantage of cooking is that, as you say, it makes some nutrients more easily available. And it also makes the basic calorific content of the food more easily available by breaking down the cell-walls in plant foods. Richard Wrangham's anthropological book "Catching Fire" would be one to look at on this.

The heat can also help to break down some "antinutrients" in plant foods. Most people in the general public haven't heard much about these. The first mainstream "diet" book to talk much about them was Professor Loren Cordain's "The Paleo Answer" (2012). Basically, if you look at the problem from an evolutionary point of view you realise that the problem plants have is that, unlike animals, they can't run away from a predatory threat. What they do is fight back with chemical warfare. This is to express what's going on in somewhat metaphoric and anthropomorphic language, but you get the idea ... if there were not chemicals in many plants that would give potential predators that ate more than a certain quantity a pretty bad stomach ache, those plants simply wouldn't be around now. Some plants have other "defences" - spines, growing underground, etc. - but chemical defences are fairly common. Some plant-poisons can even kill.

Cruciferous vegetables, such as cabbage, have goitrogens in them - i.e., chemicals that can interfere with the thyroid. And this probably explains why cabbage is cooked for a long time in traditional societies where if people lack scientific knowledge they nevertheless have plenty of *practical* knowledge of foods and cooking methods based on experience over generations.

I doubt a little coleslaw now and then will do a healthy person much harm, but someone who is diagnosed with thyroid problems (not uncommon in modern society for whatever reason) by his or her doctor probably should probably be careful:

IIRC, Professor Cordain mentions that potatoes have two main antinutrients in them -- alpha-chaconine and alpha-solanine. (Try googling "alpha-chaconine alpha-solanine"). This probably explains why, traditionally, potatoes are usually peeled, since I think these tend to be in greater concentration near the skin. Whether these particular antinutrients are heat-labile I don't know.

I don't know why anyone would choose to eat potatoes undercooked. The only thing I can suggest is that perhaps undercooking them makes them less easily digested, so that the energy that is locked up in the starch becomes available over a *longer* period. But that's the merest guess.

Shay said...

I'm not a chemist or a nutritionist so I can't comment on how healthy undercooked potatoes might be.

I do remember a passage in "A Tree Grows In Brooklyn" where Francie and her brother are offered a choice between an apple and a raw potato to snack on. They take the raw potato because it costs less than the apple.