Bread is not what it used to be; or, more particularly, supermarket bread is not the same as was made in the village bakery. This is the claim of many whole-food and healthy living advocates. The common test quoted is to squeeze a small piece of bread between the fingers. factory bread will squash into a glutinous ball and “real” bread will crumble.
I can remember when I was young that it was “steam baking” that was blamed. The implication was that the steam got into the bread and made it soggy. This is rubbish of course. Steam ovens were as dry as any other sort, they just used super-heated steam in pipes to heat them. There would undoubtedly be a difference from an open flame gas oven but not from electric heating.
More recently the Chorleywood manufacturing process (PDF) is blamed. This was invented in 1961 and was rapidly adopted by all large scale manufacturers as it dramatically reduces the production time. Yet an academic report in 1966 (Chamberlain, et. al. PDF) concluded that there was very little nutritional difference in results from previous methods, thought it should be noted that it was comparing against a previous industrial process.
So what goes into bread? The basic ingredients are flour, mostly wheat (100 units), water (55-60 units by weight), yeast (1-2 units) and salt (1-2 units). This doesn’t vary much whether made industrially or domestically. There may be small amounts of other ingredients, fat/oil (1 unit) is used to soften the bread. Acetic acid (vinegar) can be used as a preservative. Commercial bread also includes some proprietary additives which include fungicides (to stop mould) and emulsifiers.
Some additives are out of the control of the bread makers—flour has to contain certain minerals and vitamins by law and these have to be boosted with flour improvers if not naturally present, which is always the case except for wholemeal flour. This is also true for flour bought for home baking, whatever the source.
So what difference does the Chorleywood process make. It uses about double the yeast because it has to act faster. It uses hard (hydrogenated or fractionated) fat which is high in chloresterol and a very small amount of Ascorbic acid (Vitamin C) is added to aid the release of gluten. The speed of the process may also retain a higher moisture content before baking but it won’t be huge. I suspect that any other differences when compared to artisan bread are more down to the quality of the flour and industrialisation rather than the process.