All grains contain peptides that mimic morphine or endogenous opioid substances. This is where I deal with my latest loaf craving. Get your bread-based exorphin fix here.

Wednesday, November 7, 2012

18% Rye Bread and thoughts about getting Stale

I made this 18% Rye Bread at Halloween.  It is the last bread I make before the kitchen is ripped apart, and I have no ovens, or counters, or cupboards, or even walls and floor for the next few weeks.

  • 82% ww
  • 18% rye
  • 72% water
  • 2% salt
  • 20% starter
  • 5% wheat germ

Why Write about Bread?
It has become old hat now for me to make bread on my days off, and to write about the bread (and what I'm thinking about as I make the bread).  Often the thought is about how to make bread better, or healthier, or my thoughts about food in general; sometimes my thoughts range far afield.  Occasionally I'm introspective.

Today I'm recapping for myself why I began writing about my bread.  I originally simply wanted to make a whole grain bread because I couldn't buy one I liked anywhere.  I wanted to learn how to make one myself.  I wanted to understand how others did it (or if they didn't make whole grain bread, why not?).  As I taught myself through recipes, and reading about bread, and grain, as I experimented, I discovered a lot of stuff I had never thought of before, and I began passing it on.  My curiosity drove me deeper into a lot of different subjects.

But why write at all, once one has a handle on making bread?  Why continue to write?  Why write in the first place?

Obviously, to me writing is a compulsion every bit as addictive as the bread I make.  And it began at a time when I sorely needed to express myself again in words, when due to the nature of my work, as a nurse in a hospital palliative care unit, I wasn't allowed to write much of anything that was significant to me.  Bread was a hobby, blogging about it became a way to discuss things that were everyday, but intrinsic to life.  It became  a way of expressing life in the midst of death.  My way of saying to the world at large, "I may be just talking to myself, but I won't be muzzled."  And I felt like I was being muzzled, at work.  I felt like I was told that I had to shut up and be silent, as I watched patients die, as I watched co-workers bear the brunt of the terrible emotional toll, as I watched the healthcare bureaucracy undermine nursing care at every corner.   Writing about bread became for me a distraction, a purpose, a way to reclaim some small core of silly personal meaning in a life consumed with everyone's ultimate meaninglessness.  It was a way for me to temporarily take my mind off things too profound to contemplate any longer.

So suddenly take all that away -- force me to eat only bread that I've managed to squirrel away in the freezer, in preparation for this season of no-oven, no-baking; stop me from writing, while my frozen stockpile dwindles; muzzle me, once again -- and what will happen?

I feel my patience wearing thin, my raw emotions numbed, my thinking growing as stale as my thawing bread.  Anyone following this blog will know that I've been fasting 2 days a week; now, not only am I refraining from eating bread on certain days, I will be stopping from writing about it, for the duration of the kitchen renovations at least.  Will my frayed nerves be able to take it?

Or will I just end the blog here, and move on to something different?

How Bread Stales
Ever since I visited Red Cat Farm to try Master Baker Christian Burdan's Passion Bread (and was astonished to see how quickly his loaves staled, compared to my own homemade sourdough loaves), I have been trying to research bread staling in my spare time.  

The wiki on bread staling is currently little more than a stub.  But as you can imagine, there is a LOT of information on this topic "out there."  The baking industry** has wanted to slow staling, since it represents loss (Gomez reported that "3% of the production of bread is returned for problems of staling in the shape of unsaleable bread," and I have conjectured that the true loss is much higher); so lots of dollars have been spent to study staling from virtually every angle imaginable.  

But the strange thing is, despite over a century of applied science, "bread staling is still not completely understood"  (D'Applonia).  Even defining staling can be tricky.  "Staling refers to all changes that occur in bread after baking" (D'Appolonia), and so "commences as soon as the loaves are cool, if not before" (Cornford).  

Some scientists have looked at staling as a continuation of the process that begins with mixing and baking.  Temperature changes are important to this process, and so oven temperatures, cooling and even freezing have all been studied for their effects on staling, as have pH and the micro-organisms involved in fermenting. 

Still, there remains a subjective element to staling -- we know it when we see it --  and Bales defined staling entirely in terms of customer organoleptic perception:

"The staling of bread can be defined as the decrease in consumer acceptance caused by changes in the crumb and crust undue to microbiological action. The percentage of consumer acceptability of white bread declines in relation to storage duration [8]. This is caused by a declination of bread’s sensory qualities as the length of storage increases [20]. Since eighty percent of bakery sales are impulse purchases motivated by perceived freshness [19], the qualities of bread that indicate freshness are crucial to any acceptable loaf."  

Cornford reported that "Differences of only 2% in crumb moisture are distinguishable by taste."  

While we do not require the many techniques that have been used (X-ray crystallography, electrical conductivity, digital imagery, differential scanning calorimetry, CP MAS (cross-polarization magic-angle spinning), DSC (differential scanning calorimetry), DTA (differential thermal analysis), MRI (magnetic resonance imaging), NMR (nuclear magnetic resonance spectroscopy), etc. ) to detect staling, these various scientific investigations have revealed a lot about structures beneath our perception, and a picture of the micro-processes involved (e.g. "increase in crumb firmness, loss of flavour, decrease in water absorption capacity, amount of soluble starch and enzyme susceptibility of the starch" (D'Appolonia)) is beginning to emerge.

Gray and Bemiller have organized for us and reported on much of the most important research done on staling, and is perhaps our best, easily accessed source.*  

"Bread is an unstable, elastic, solid foam, the solid part of which contains a continuous phase composed in part of an elastic network of cross-linked gluten molecules and in part of leached starch polymer molecules, primarily amylose, both uncomplexed and complexed with polar lipid molecules, and a discontinuous phase of entrapped, gelatinized, swollen, deformed (wheat) starch granules. Neither the bread system nor the staling process is understood well at the molecular level."  

In other words, it has long been known that "starch retrogradation is the most important single factor causing crumb firmness, but there are many contributing factors" (D'Appolonia).  

My understanding, based on my reading, is that bread crumb is a latticework of mostly gelatinized starch made up of interwoven layers of amylose and amylopectin, and this network is variously affected by the addition of fats and protein (whether from the grain itself, or as further ingredients of the recipe), some of which also bond to the starch, and exchange (attract and repel) water molecules (hydrogen and oxygen atoms).  The net also traps gases, which have been incorporated into the lattice through the mechanical process of kneading, and through fermentation, and these add to the network's structure upon baking more than to the later staling process.

How the bread lattice structure continues to change over time remains a mystery, and rheological models, foam models, chemical polymer models and models of kinetics have been variously used to describe it, as have the physics of emulsions and colloids

Often in the science literature one finds bread dough or a finished loaf described with the terms "dispersed phase," "continuous phase," "discontinuous phase," "elastic foam" and "crystal" and these refer to where the starch in the loaf fits in the hydrocolloid scales.  At one time or another, bread dough or baked and staling loaves will fit into one or more of these several categories.

Things get complex fast.  But it would appear that we still don't have an appropriate single model that will describe for us how crumb forms and firms during mixing and baking, and without that, we cannot hope to explain further changes due to staling that happen hours, and days, after the loaf is cooled.

It would appear that the amylose (20-30%) begins to retrograde almost immediately upon the bread's cooling, and this happens even before humans can detect it, within about 5 hours (Lee and Lee).  It is the retrogradation of the amylopectin (70-80%) layers that is detectable by us, and this happens over a time period of days.  It may be that in the first 2-3 days, water is leached from the amylopectin, and beyond 3-4 days, water is leached from the protein bonds, as the loaf stales further.  At least, we currently assume that the way the protein (gluten) interacts with the amylopectin, and how water is exchanged between the molecules, likely has something to do with the perceived staling.  

D'Appolonia created this triad of the main elements of bread to provide a visual aid to the interactions that are possible in how we may view staling.  Essentially, if we strengthen and/or optimise the elements that build bridges between the different layers to stabilize them, we can theoretically retard the leaching of water from one element to the next, and thereby slow staling:

What the home baker needs is not merely a list of ingredients that can be added to dough to keep it from staling (like what the Big Boys use).  Rather, we simply need a list of things to do that will improve the freshness and keeping ability of our loaves.  Unfortunately, there are a lot of variables, and even a table as simple as this is going to be true sometimes, and false at others.  This is the best I can do with what I know.

Action Increases
Refrigerate Y
Experiments have shown that bread stales quicker in the refrigerator.
Freeze it
Y Stops the movement of water, which leads to retrogradation.  But when thawed, the bread will stale quickly.

Y Spontaneous sourdough fermenting decreases staling, if the sourdough starter is kept to a baker's % of around 20%.  At zero, or 40%, detrimental effects will be seen in the loaf firmness, and increased staling.  The mechanism appears to involve lowering pH, and may be yeast-specific, meaning certain wild yeasts may produce proteolyses, and some will produce amylases, which will affect the loaf.  It is suspected that hydrolysis of the starch (and thereby the production of dextrin, which interferes with starch crystallization) is involved, but experiments on this have so far been inconclusive.
More Lactobaccilus
Y Lower pH of dough through increased lactic and acetic acids brought about by natural fermenting generally decreases staling
More Pentosans
Y Wheat contains pentosans (non-starch pentose polysaccharide polymers), but rye contains more.  You can add some rye to wheat breads and it will improve staling.
More Fats
Y Neither grain's native lipids nor added oil or shortening will slow retrogradation of starch, but staling is reportedly slowed; the suggested mode of action is through the formation of lipid-protein bonds, but the full mechanism is unknown
More Glycolipids
Y The more glycolipids in the dough, the fresher the loaf appears.
Put it in the Oven again
Y It is well known that you can improve a bread's staleness temporarily by heating it in the oven again.  This liquifies the gums of the network of crumb structure -- but upon cooling, it will stale even quicker.
Increased Hydration
Y If there is more moisture incorporated, it will take longer to retrograde the starch.  The caveat being, it has to be incorporated into the structure of the crumb; the dough has to actually absorb it.
Adding Sugar Y
Adding sugar has an effect on the starch gels.  With increasing sugar concentration, the water's plasticizing ability is reduced, and the gelatinization temperature increases.  Disaccharides hydrate water molecules, and inhibit ice formation, leading to better freezing for doughs.
Increased Baker's Yeast
Y ? Lowers the firmness and the firming rate of the loaf, which is not quite the same thing as the staleness, but has similar organoleptic properties.
Increased Fermentation
? Increases protease activity, which will affect the bonds of the proteins and starches.

Y Alpha-Amylases have been used alone or with other enzymes, to improve the staling of loaves.  Proteases, Lipases, Hemicellulases and Xylanases have also been shown to reduce staling over long periods of storage.
Adding Emulsifiers and Hydrocolloids
Y These are commonly added to store-bought bread these days.  On labels, you might see sodium stearoyl lactylate, monoacylglycerols, lecithin, carboxymethylcellulose, hydroxypropylmethylcellulose, alginate, diacetyl tartaric acid esters of monodiglycerides, etc.  For home baking, you might try adding locust bean gum, xanthan, whey protein, dried baker's yeast, and guar gum, if you must

Y Unknown mechanism; dextrins are formed from the hydrolysis of starch, and ordinarily hasten staling.  But adding dextrins may somehow keep starch molecules larger and intact for longer.

Y Reduces bread staling, possibly because the fibre holds the water in place longer.

This 18% rye was a fine bread.  It actually held up pretty good -- and I find that rye breads made with sourdough generally do not stale as quickly as wheat breads.  I suppose that this is because by adding rye, we are increasing the percentage of pentosans (non-starch polysaccharides, mostly arabinoxylans) in the dough.  This was only 18% rye, and it still had a positive effect on lengthening the time until it staled.  It lasted through a couple of fasts, so one loaf lasted all week long.

If I can manage on that amount of bread, I might just have enough loaves frozen to last me until I get my kitchen and oven back in working order.

Notes to Myself

Thursday, November 1, 2012

Bread with Seeds and the Glycemic Index of Bread

Bread with Seeds

A couple more breads to stick in the freezer, against the coming kitchen renovations.  

These loaves were deliberately made to be dense.  I usually get my hydration up much higher than this.  But this -- and other recent experiments with low hydration, high density bread (aka "bricks") -- have been trials in preparation for some non-wheat naturally fermented doughs I want to play with.

1. 10% Rye Bread with Seeds

The seeds are 211g of sunflower and pumpkin seeds.  The hydration is 62%.  The rest of the ingredients are the usual: 90% whole wheat, 6.7% wheat germ, 20% sourdough starter, 2% salt.

This bread went right into the freezer.  No crumb shots.

2. Whole wheat bread with Amaranth Seeds

100% whole wheat, with 6.8% wheat germ, at 65% hydration.  I added 200g of amaranth seeds. Kneading this dough felt like petting a lizard.

I ate one of these breads, the other went into the freezer.  Probably neither of them were good enough to give away.

Thoughts on the Glycemic Index

I have been reading about "The Glycemic Index", (a scale developed in the early 1980s by Toronto researcher Dr. David Jenkins and now a fairly complete table of virtually all foodstuffs that you can buy that contain carbohydrates). The scale ranks carbs according to how they spike the blood sugar.  This is important information for diabetics, and for people who want to lose (or maintain*) weight.

And those unfamiliar with regular use of the scale, like me, are often surprised to see where bread falls on the scale.

The scale usually ranks foods against pure glucose, the sugar all cells of the body use for energy.  Glucose is given a value of 100.**  

Table sugar (sucrose), which is only half glucose (the other half being fructose), gets a value of about 65, but (using the table at bread can be even higher (depending on the type of bread, the index can range from 51 (pumpernickel, whole grain, 1 oz.) to 95 (French baguette).  As wikipedia states, the values on the Glycemic Index can be counter-intuitive.  As is frequently pointed out, candy bars can have lower numbers on the glycemic index than whole grain bread.
I wanted to know where my own sourdough bread -- not a purchased bread -- might fall on this scale.  So one night at work when we weren't too busy, I tested my blood sugar.  I had been fasting for 25 hours, and at midnight I broke my fast on a single 89g slice of bread (with nothing else on it).  This was my dense whole wheat sourdough bread, with a tiny bit of amaranth seed in it.  At midnight I measured my fasting glucose, and thereafter I tested at 15 minute intervals, for 2 1/2 hours.  The following table shows how my blood glucose levels spiked.  These are Canadian values (measured in mmol/L, unlike the US values, which are measured in mg/DL.  To get the comparable US value, you'd have to multiply the BG value by 18.  Normal fasting range for non-diabetics in Canada is 3.5-6.5).

During the 2 1/2 hour period, I ate nothing else, but I did drink a bit of black tea.

TIME BG (mmol/L)
0000 3.7 (fasting baseline)
0015 4.2
0030 5.3
0045 7.4
0100 7.9
0115 7.2
0130 6.7
0145 5.9
0200 4.6
0215 4.3
0230 4.6

I was using 89g of bread, not the usual 50g of bread that the glycemic index is built upon, but still, you can see that the 1 hour peak of my blood sugar was 7.9, so the glycemic index would probably fall somewhere around 79.

Why is bread higher on the Glycemic Index scale than table sugar?

Wheat is roughly 12% protein, 12% fiber, 1.5% fat,  71% carbohydrate, and the rest is ash (iron and other minerals) -- so bread made with wheat is going to fall into this sort of breakdown too (assuming it hasn't had parts -- like the fats and fiber -- removed).  The carbohydrate, or starch, is made up mostly of amylose (20-30%) and amylopectin (70-80%).  Amylose is a sugar made up of glucose units -- as many as thousands, mostly strung together linearly -- but it turns out that it is difficult for humans to digest, probably because of the varied shapes the multiple loops make, and because it is water insoluble.  But your gut flora -- all those good bacteria in your bowels that keep you healthy -- can digest much of it as it passes through.  In return for giving them amylose, they give you other things -- like more probiotic bacteria, digestive enzymes, vitamins, and gas (nothing says "it's partytime!" more than happy gas).  Amylopectin, on the other hand, is soluble in water, and is considered a complex carbohydrate.  Also made of glucose, amylopectin is highly branched and tightly packed.  The molecule's complexity is nothing to the human body, though, because we produce amylase, both in the mouth and in the gut, and this enzyme very efficiently liberates the glucose and allows it to pass directly through the digestive tract lumen into the bloodstream.  The wheat plant has stored a lot of energy in the seed; it is designed to provide a young seedling with a big boost for rapid growth -- kind of like what breast milk does for infants.  And when we eat it, we consume that concentrated energy that we can immediately use.

As blood glucose levels go up, insulin is released by the pancreas, which takes glucose out of the bloodstream and puts it into cells that need it.  What happens to excess blood glucose that the body can't immediately use?  The liver scoops up some of it and makes glycogen, which is a packed form of glucose, even denser than amylopectin.  This can be later taken apart and dispersed to the other various organs as required.  The muscles also keep a store of glycogen nearby for their own rapid use.  But what happens when we have enough glucose for cells, and enough glycogen stored?

If we've still got more glucose than we need, insulin levels continue to rise in the bloodstream. The liver takes notice and begins to make fatty acid synthase, which begins the cycle of converting glucose into pyruvate, then acetyl CoA, than fatty acids. These circulate as triglycerides, which are taken up by adipose tissue, packing it as lipids.  If all goes well, the fat cells send out leptin, a hormone that suppresses appetite (they are saying, "enough already!")  In conditions of low carbohydrate input, the stored fatty acids can be broken down again to glucose for energy -- but this metabolic pathway is expensive, and it always seems easier to just eat more carbs to get energy, and that is one reason why fat is so difficult for many people to get rid of.

Fatty acids are ingested mostly from meat and dairy; but if you are not eating these things, your triglyceride levels might still be high if you get too much energy from any source, including carbs, especially wheat.

The Glycemic Index is a good tool for diabetics who need to learn to control the rapid rise of glucose in the bloodstream.  Eating low on the scale will keep the body's blood glucose at a nice, healthy level.  Bread may have its place in a diabetic's diet, but the danger is, it can raise the blood glucose level very high very quickly, without the pancreas' ability to safely modulate the levels.

But the GI Index is not the complete story for safe eating practice.  Satiety plays a large part in keeping one's energy intake high enough, but not too high: I've mentioned the hormone leptin which can modify our appetite.  Fiber may also play a role in keeping one from overeating carbs (and if we take the fiber out of our grain and eat only the starch, this can have dangerous consequences, and is one of the reasons why we are told that whole grains -- as opposed to grains with germ and bran removed -- are important).  Furthermore, bread is not often eaten as I did for this experiment, alone and without anything else.  When we add proteins or fats to our bread, or even other carbs, it will modify somewhat the rather sharp glucose rise that we see (sometimes because of delayed gastric emptying, sometimes for other reasons) -- unless we are diabetic, of course.  For diabetics -- for whom this glycemic index was developed -- it becomes even more important to eat low on the GI scale, and to make sure we don't consume more calories than we really need.

Others have proposed a scale that rates fullness, or satiety, in concert with the Glycemic Index.  Still others propose a scale that ranks foods with a better antioxidant profile.  In all of these scales, vegetables are at the end of the list that are best, fruits are towards that end too, and everything else is not.  Most diets (except perhaps the extreme high protein diets) will advise you to eat more vegetables and fruit.  

I'm glad I read about bread's glycemic index.  It shows me that bread is a high-energy food source.  It also reminds me to find more of my carbs from vegetables and fruits, whenever possible, and not to be so worried about eating bread with fats like butters, oils, eggs and cheeses.

Bread Results
This wasn't a particularly good bread, certainly not one of my favourites.  As I indicated, it was pretty dense, and although it was okay tasting, I've certainly made better.  The amaranth seeds were pretty much invisible to taste and mouth feel, so they seem to have added just about nothing to this loaf.

Notes to Myself

  • * Using bread to maintain weight is something not to be scoffed at. Plenty of people with illness or malnutrition due to dietary insufficiencies or allergies can benefit from the high energy to be obtained from whole grains.  People who can't afford a diet rich in varied organic fruit and vegetables can still maintain their caloric intake using whole grains.  
  • ** In practice, no one eats pure glucose, so this was felt to be a difficult scale for diabetics to put into practice in their everyday life. At one time, the glycemic index was therefore scaled to white bread at 100 (and on this scale, glucose gets a value of 140).
  • Incidentally, after the 2 1/2 hour mark, when I quit testing my blood glucose levels, I decided to eat even more carbs: an apple (Glucose Index 38) and then a banana (Glucose Index 55) and finally an orange (Glucose Index 44). The effect on the carbs is not additive, but rather averages out, believe it or not. An example of what I mean is sucrose (GI 65), which contains half-fructose (GI 19), half-glucose (GI 100).
  • I highly recommend this blog entry, authored by Chris Masterjohn and linked from the Weston A. Price Foundation's webpages, which discusses the book "Wheat Belly" -- including Davis' use of the Glycemic Index to show that wheat spikes the blood sugar and makes people fat.  In particular, Masterjohn says:

    "But there is no evidence that minor fluctuations of blood sugar within the normoglycemic range cause harm, and a little bit of fat will nearly flatten the glycemic index of a carbohydrate-rich food in healthy people.  Whether insulin makes people fat is currently a matter of vigorous debate and Wheat Belly would have benefited if Dr. Davis had presented this relationship as a hypothesis rather than stating it as a simple matter of fact."

    Incidentally, both Davis and Masterjohn mention the 'exorphin' thesis -- that grain contains morphine-like substances, and this can explain why hunter-gatherers with good health moved to a less healthy agricultural/community-based diet.  Masterjohn says that exorphins are now found in lots of different plants (and of course they were discovered in dairy products around the same time they were discovered in wheat) and he suggests that they are likely to be pretty much ubiquitous in our food.  He also says that their biggest effect in humans is to delay food's passage through the gut.
     I see this all the time in my work, as I try to alleviate constipation in my patients in palliative care who are experiencing this primary symptom of pain management using narcotics. Whole wheat, due to its fiber, will alleviate much of this potential problem (and not to minimize the other effects of exorphins, I am of the opinion that some people who have wheat/milk allergies, sensitivities and trouble metabolizing them may also experience some central nervous system effects, as seen in autism, schizophrenia and certain dementias.  It may also have some addictive and euphoria properties too, who knows?).

    T. Wolever, author of "The Glycaemic Index: a physiological classification of dietary carbohydrate" (2006) defines the glycaemic index in this way:

    The GI is defined as the incremental area under the blood glucose response curve elicited by a 50g available carbohydrate portion of a food expressed as a percentage of the response after 50g anhydrous glucose taken by the same subject.

    Therefore, I have not determined the GI of my bread, since I did not obey the rules -- which would involve my fasting the correct number of hours (I fasted too long, which may lower the baseline glucose level too far), taking the correct amount of food (I needed 50g of carbs, and I calculate there was about 64g of carbs in this 89g slice of bread), and determining the mathematical area under the curve (which of course I didn't do, see below for a hint about the formul), and doing the test several times (didn't do it but once), comparing it to my response to pure glucose (didn't) and averaging out the Blood Glucose response of several people (it was just me).  All I have done, so far, is to show my own Glucose Response for one slice of my bread, over a short period of time.

    Glucose Response is individual, and can be affected by changing other parts of the diet.  Wolever explains:

    It is known that fat and protein affect glycaemic responses, but these effects have nothing to do with the glycaemic response of the carbohydrate. In addition, the effects of added fat and protein on glycaemic responses differ in normal subjects, subjects with type 1 diabetes and subjects with type 2 diabetes… On the other hand, the GI of individual carbohydrate foods is the same in all of these different types of subjects….The terms ‘glycaemic index’ and ‘glycaemic response’ should also not be confused because these entities have different mathematical and statistical properties.

    On p. 17-18, Woelver discusses different methods for determining the Area Under the Curve (AUC) mathematically.  The simplest appears to be the trapezoid rule, but "polynomial interpolation of third and fourth degree, Simpson's integration and cubic interpolatory splines" gave slightly more accurate results (variation about 2%).  Since I messed up the test, and probably can't correct for the errors in procedure, I won't be doing the math.  But at least I have an idea, how to do it in the future.