A few days ago, you mentioned the difference between the protein content of modern and ancient wheat varieties. We've seen that mentioned before, and I've always wondered just what the details really are, so I spent most of the weekend trying to track down some information on that. I guess I'm not as good at finding information as I thought I was, because it took a heck of a lot more time that I expected to have to devote to it, and I ran into countless dead ends. (But then, I'm bad about allowing myself get sidetracked, also. LOL). Anyway, after reading enough about plant genetics, cereal chemistry, and neolithic agricultural practices, to burn me out on that stuff for a long time, I finally managed to find the piece to the puzzle that I needed, to make sense of it all. (I think). Here's a quote from what you posted, in case anyone else wonders what I'm referring to.
So here's more than you ever wanted to know about the accession of wheat over the past 15,000 years or so. I'm trying to make this as brief as possible, to keep from putting anyone to sleep, but if you, (or anyone), want more detail, please don't hesitate to ask.Polly wrote:Mike, re modifed wheat.....I read that the wheat our grandparents ate was only 3% gluten. Wheat today is 50% gluten. They have increased its gluten protein fraction because that is what makes baked goods so light and airy. Maybe we have family histories rife with genes for gluten sensitivity, but it would never have become apparent if our ancestors ate such small amounts.
The oldest ancestors of modern wheat that are well known, are eikorn and emmer wheat, (and spelt, but let's limit this a bit for brevity). There is evidence suggesting that wild einkorn grain was harvested in the late Paleolithic and early Mesolithic Ages, 16,000-15,000 BC. Confirmed finds of wild grain remains have been dated to the early Neolithic (Stone Age) 10,000 BC. Cultivated einkorn continued to be a popular cultivated crop during the Neolithic and early Bronze Age 10,000-4,000 BC giving way to emmer by the mid-Bronze Age.
Remnants of wild emmer in early civilization sites date to the late Paleolithic Age 17,000 BC. Cultivated emmer emerged as the predominant wheat along with barley as the principal cereals utilized by civilizations in the late Mesolithic, and early Neolithic Ages 10,000 BC.
Compared with hard red wheat, einkorn is considered to be more nutritious, based on the higher level of protein, crude fat, phosphorous, potassium, etc., but the kernel is/was much harder to separate from the glume, (chaff). Gluten, of course, is what provides bread dough with the elasticity it needs to trap gas produced by fermenting yeast, and therefore to “rise” or expand. The gluten of the einkorn accession, (the einkorn that still exists today), has a gliadin to glutenin ratio of 2:1 compared to 1:1 for modern bread wheat. . Emmer, on the other hand, has a gliadin to glutenin ratio of 6 to 1. (The 1:1 ratio for modern bread wheat correlates with your statement that "Wheat today is 50% gluten"). What you meant to say, of course, (I think), is that wheat gluten today is 50% gliadin, (the other 50% is glutenin, and it is the gladin to glutenin ration that determines the baking qualities of any given wheat flour). The 2:1 ratio of einkorn, corresponds very closely with the harder modern red wheat varieties, (such as durum), which are used for pastas.
Modern wheat, of course, only has roughly 10 to 17 % total protein, (depending on variety), with the preferred bread wheats averaging around 13 %. The ancient wheats had far more protein. In general, the protein level of any crop, varies inversely with the yield. IOW, the higher the yield, the lower the protein, and visa versa. That's why the ancient wheats had higher protein - they weren't "improved" to benefit from enhanced production techniques.
Hard red winter wheat, (bread wheat), averages about 13 %, and though that figure varies from year to year, depending on growing conditions, the average hasn't changed in a long, long time. For example, I found a record of every wheat crop grown in Kansas, since 1866, and they even began reporting protein content, and other vital statistics, in 1948, (if I remember correctly). The long-term average was steady, and still is.
There are four protein fractions that together make up the protein in wheat , but the albumins, and globulins are not of interest here, because, while they do contribute to allergic reactions, they don't play a part in gluten-sensitive enteropathy, nor do they serve to enhance the baking qualities of wheat flour. The gliadins and glutenins in the prolamin fraction, plus the glutenin fraction, combine to comprise what we know as gluten, which amounts to about 80 % of the total protein in hard red wheat, used for baking bread. That means that hard red wheat is about 10.4 % gluten, of which half is gliadin, and half is glutenin.
Both einkorn and emmer are still around today, and when grown side by side with modern wheat, under similar conditions, (without nitrogenous fertilizer), the protein content of the ancient wheats will always be 50 to 75 % higher than modern hard red wheat. (That's not a misprint).
Today's accessions of emmer wheat, for example, show an average gluten fraction of about 45 %, (rather than 80 %), with an average total protein level of around 20 or better, which puts the gluten content at about 9 % or better, (compared with 10.4 % for hard red winter wheat). IOW, they are pretty similar in actual gluten content, (though it has a different composition), and remember, this wheat has been around for close to 20,000 years.
"But", you say, "these accessions have been improved by selective breeding for thousands of years". True, but breeders always select for higher yields, (all things being equal), and remember that as yields go up, protein goes down, (that's true of all plants, to the best of my knowledge, not just grains). Ergo, odds are very high that 10 or 15 thousand years ago, those ancestors to modern wheat had even higher protein levels , because they are capable of pretty decent yields, today.
The big question in my mind was, when did wheat first achieve the balance of gliadin and glutenin necessary for good bread-making characteristics? IOW, when did "modern" wheat varieties come into existence? Well, one of the surest way to identify plants is by their chromosomes. Early wheat plants looked like grass, and had fragile stems with hulls that clung to the grain. This made them hard to thresh but perfect for reseeding themselves.
Primitive women first gathered einkorn, (Triticum monococcum), a diploid variety, (meaning it contained 14 chromosomes). They selected it because of its larger seeds, and ease of threshing and harvesting. Their success led early humans away from hunting societies, as the new agrarian communities discovered that they could "stay put", and survive quite well on cultivated crops.
According to the folks who study these things intensively, a natural outcross between einkorn and another 14-chromosome variety, Triticum spletoides, produced a wild wheat called Triticum turgidum, which had 28 chromosomes, making it a tetraploid. This new wild species led to emmer, which was soon the preferred variety. The durum wheat which we now grow to make pasta, was originally selected from wild emmer wheat, with large easy-to-thresh grains.
Modern bread wheat varieties have 42 chromosomes, (hexaploids). These evolved from a natural outcross between emmer wheat and another diploid wheat, Triticum tauschii. Triticum tauschii was the source of the unique glutenin genes that give bread dough the ability to form gluten with the magical ratio of 1:1, (gliadin:glutenin), and apparently the quality of the glutenin was far superior to previous versions. The offspring of this outcross is called Triticum aestivum. Before that point in the history of agriculture, wheat kinda sucked, for bread-making.
So, I was wondering, "When did this happen?" - was it 50 years ago, or 5,000 years ago? (Okay, I admit that I knew it wasn't 50 years ago, because I've lived on a farm longer than that, and I know from experience that wheat hasn't changed significantly in the last 50 years). So when did that milestone outcross occur? According to the Washington University in St.Louis:
http://www.nslc.wustl.edu/courses/Bio34 ... /wheat.pdfShortly after the appearance of agriculture a hexaploid species arose (2n = 42)
3 sets of chromosomes, two from a tetraploid emmer wheat and another set from a
diploid species T. tauschii.
Is called T. aestivum Hexaploid wheat has an endosperm that is especially high in
protein and surpasses other wheats in making bread.
There are over 20,000 cultivars of hexaploid wheat
Well, we still don't know exactly when it occurred, because the dawn of agriculture apparently came about somewhere between 10,000 and 20,000 years ago, but I believe that it's generally conceded that by 10,000 years ago, agriculture was very well established. That implies then, that for all practical purposes, all of the same basic wheat cultivars that we are growing now, were available over 10,000 years ago, and probably much longer. Apparently, though, just because they were all available, does not mean that they were utilized to any great degree, because it is reported that emmer wheat dominated production in those days.
So we still don't know when the "bread" wheats really began to catch on, and take over the production acreage. Obviously, though, our ancestors were eating wheat with probably at least 9 or 10 % gluten content, for at least 10 or 15 thousand years. In fact, conditions are actually much better now, (gluten-wise), than they were during the period while emmer wheat was the primary choice, (beginning about four or five thousand years ago, and lasting until probably only a couple hundred years ago. Consider this: While glutenin is not totally without fault, most of the toxicity in gluten lies within the gliadin fraction. Therefore, with it's 6:1 gliadin to glutenin ratio, emmer wheat contains about 7.65 % gliadin, (20 % protein, times 45 % gluten, times 6, divided by 7, to calculate the gliadin fraction), compared with 5.2 % for modern hard red winter bread wheat, (which we calculated above).
IOW, contrary to "urban myths", we're eating wheat with less toxicity, than the wheat that our ancestors ate.
I know, I know, it surprised me too, but if you want to see them, I can produce references on all this stuff. If I've made any mistakes here though, I would sincerely appreciate being pointed in the right direction.
Love,
Tex
P S If all this is true, then what is causing the current "epidemic" of gluten sensitive enteropathy? Why would it happen now?
