Pages

Monday 24 November 2014

Curious Cook: The white loaf deconstructed

Sunday November 23, 2014

Chris Chan

This post is on Healthwise


The must-have Roti Bakar with half-boiled eggs.

The must-have Roti Bakar with half-boiled eggs.


What’s in a loaf of white bread? Not just flour, water and salt, it’s more interesting than you think!
Chemically, there are many clever (and rather interesting) compounds and enzymes which are used by commercial bakeries to keep bread soft for many days beyond which normal bread would have turned into lumps of wood. I won’t go into all of them because commercial bakers have an arsenal of several hundred combinations of chemicals, enzymes and other additives which they can use to treat the bread that you eat. Not all of them are for the preservation of bread, I might add. Many are used for improving the texture or flavour or even colour of bread – just so that you are tempted to buy them. Simply put, bread is big business and commercial bakers have to make a profit.
Fresh bread out of the oven.

The rest of this article is about the wheat flour and just a few of the additives and more funky chemicals (including their curious alternative applications) that may be found in commercial breads around the world. Please note that these additives are generally not toxic or dangerous in the concentrations permitted for use in bread loaves (as that would imply that the authorities looking after our food safety are incompetent). But I will confess that I don’t tend to eat commercially-produced bread, though it is not for the reasons you might think – it will be explained later.
Let’s start with the flour
To maximise yields from the wheat plant, laboratory botanists have developed hybrid strains of wheat which provide more of the stretchy gluten needed for baking. This has come at a cost of lower mineral content and nutrition, around 40% less in terms of minerals alone.
Ironically, due to the lower nutritional value, we tend to eat more wheat-based goods to make up for the deficit. To exacerbate matters, over the last 25 years or so, modern farmers have been boosting grain yields by adding sulphur and nitrogen compounds to the soil to bulk up wheat before harvest.
The resulting flour has double the amount of fast and slow omega-gliadins of the old original wheat – and the problem is that these molecules, particularly fast omega-gliadin, have been alleged to trigger serious gut inflammations in certain humans. There is some evidence of a correlation between the increase in wheat allergies over the last 25 years to the amount of omega-gliadins in wheat.
We all know flour is white and odourless ...
What fewer of us know is that natural flour actually isn’t snow white and actually has an odour as well. To get rid of the pesky natural colour and smell, flour is actually gassed with chlorine dioxide. This would be fine except that the gas destroys the natural vitamin E and the chlorine tends to form a few nasty compounds which are left as residues in the flour. However, the concentrations of these compounds are maintained at a safe level for human consumption.
Long life
Commercial white flour does not deteriorate or grow mouldy as fast as natural flour because propionic acid is often added. This is the same chemical used to treat athlete’s foot.
What you may not know about wholegrain bread
Many people eat brown or wholegrain bread for health reasons. However, most commercial brown breads usually start with white bleached flour to which other ingredients are added to make it “brown” or “wholegrain”. Not all of these ingredients are necessarily organic and therefore some such ingredients may have detectable amounts of pesticides and other contaminants.
If you like added fibre in your bread, that is a laudable choice except that most of the fibre added is likely to be cheap indigestible vegetable fibre or in some cases, methyl cellulose, a synthetic fibre compound, which to be fair, has no known toxic side-effects and is also found in laxatives.
The long and short of bread
Commercial bread stays fresh-looking and soft for an extended period of time due to the addition of a cocktail of chemicals which usually more often than not include polyoxyethlene monostearate (which helps to retain moisture) and ethoxylated mono- and di-glycerides (which are emulsifiers used to maintain bread volume and a soft texture – they are also found in shampoos and skin creams).
To speed up the fermentation of bread (as time is money in a baking factory), ammonium chloride may often be added. Those familiar with basic chemistry will know that ammonium chloride was used as the electrolyte in disposable batteries but it is also used in anti-freeze for cars, toothpaste and washing powder. It is also linked with health problems in small mammals but there is no indication of human toxicity in the amounts permitted in bread.
The new food pyramid, a guide to healthy eating, says that kids ages 9 to 13 should eat five or six one-ounce servings of grains each day, and half of those should be whole grains. Brown bread (shown) is a good substitute for white bread. Illustrates KIDSPOST-GRAIN (category l), by Margaret Webb Pressler  2006, The Washington Post. Moved Wednesday, March 8, 2006. (MUST CREDIT: Washington Post photo by Bill Webster.)
The good and the bad
To increase the amount of air bubbles in bread and lessen the amount of flour needed to make big loaves, potassium bromate and/or potassium iodate were often added as oxidising agents, though their usage has been heavily curtailed over the years.
Why I mention them is because these chemicals have the spectacular and rather fascinating ability to reduce the fermentation time for commercial bread from between four and seven hours to just a few minutes!
Regrettably, the chemicals have also been linked to various cancers in test animals and are therefore justifiably banned in many countries. A very common replacement now is ascorbic acid, which has no known toxic effects in the quantities used in bread. By the way, oxidising agents are used to promote disulphide bond formation within the gluten molecules during fermentation (these bonds are what forms the gluten wire cages during baking).
I suppose everyone has now heard of azodicarbonamide, the material found in some fast food bread buns and also yoga mats, fake leather and shoe rubber – but most countries, apart from the US, have now banned this potentially carcinogenic chemical which was being used as an oxidising agent.
The enzyme factor
Since so many of the chemicals used for baking got banned over the years, commercial bakeries have switched to using enzymes, like amylase, which are not so easily proscribed as they are not chemicals. As an example, by adding amylase to process starch, the quantity of sugar available for yeast fermentation is considerably increased, promoting the faster production of carbon dioxide and therefore reducing the time needed for fermentation.
The taste factor
And here is why I don’t tend to eat commercially produced breads. It’s not because of the additives and chemicals, even though some might say that they are a little icky and undesirable. It is simply because breads made the traditional way just tastes so much better.
There are scientific reasons why this is the case. A long fermentation process allows the bread dough time to develop the gluten slowly – and also give the natural alpha- and beta-amylase enzymes in wheat flour an adequate period to break down starch into fermentable sugars such as maltose and glucose. The production of ethanol is also enhanced during a long fermentation process. This contrasts with the much faster commercial baking process which produces mostly carbon dioxide to fill up the additive-treated loaves and boost the volume of supermarket loaves during baking.
C’est la vie

However, everybody is free to choose and eat whatever they wish and modern supermarket loaves are about as safe as anything else you can ingest. And for modern life, convenience breads definitely serve an important purpose in providing quick sustenance in an easy flexible format, especially as they can remain useable for so much longer than a normal untreated loaf of bread.
http://www.thestar.com.my/Lifestyle/Food/Features/2014/11/23/Curious-Cook-The-white-loaf-deconstructed/

Go to Healthwise for more articles