The Baker and the Bromate

Chances are if you go to buy bread in Japan, the vast majority of it in most supermarkets comes from the Yamazaki Baking Co. and in general, it tastes pretty good. (TSE Ticker code: 2212 Equity GP)

I was surprised then, to read in a few news articles about their usage of a fairly suspect ingredient:

“They are the only Japanese baked goods company who use potassium bromate in their bread; all Japanese baking industry companies voluntarily ceased using it in 1980 due to suspicions of carcinogenicity, but Yamazaki resumed in 2005.”


I have to say that just reading that, and confirming it across several relatively respectable news stories and agencies, we effectively stopped buying Yamazaki bread and most of their other products – not actually through any fear of getting cancer from the bread, but just because it seemed irrational to continue using a suspect ingredient, when other ‘safe’ flour / dough enhancers were available.

Generally, we now buy Pasco when we do buy bread, but I did wonder whether or not this practice had crept in in other parts of the Japanese market – from Pasco’s website though, apparently not – it’s interesting they have that page devoted to it (and nicely, it’s in a URL link called ‘feeling’).

“Pasco eliminated the use of potassium bromate in 1980, and we continue to strongly stand against the use of it. We have no plans to start using it in the future. Pasco continues to observe the self-imposed control measures established by the Japan Baking Industry Association Corp. in 1992.Pasco uses vitamin C (L-ascorbic acid) as a safe alternative to potassium bromate. “

Potassium Bromate is indeed a fairly controversial chemical – broadly used historically to improve various attributes of bread dough as a flour enhancer, though through the 1970’s a body of evidence grew that it may be carcinogenic, or at least made the mutation of cells more likely.

In the European Union, it goes by the descriptive alternate name of E924. Those of us from Europe will be fairly familiar with the ‘E’ number system, which symbolically held the meaning that a food was more made of chemicals, than real ingredients, if you know what I mean. Nowadays I wonder if the E number system was to distract us from what these things actually were.

Interestingly, in the UK’s Food Standards Authority database, E924 is only listed under revocations – [link] , so apparently, it’s not allowed in the UK either – specifically having been revoked in 1990 – bakers can’t use it – the same goes for Canada (1994) and China (2005). In the US many companies were still using it in the 1990s, and it’s still legal and apparently well used today.

So why would Yamazaki Baking – and seemingly only Yamazaki Baking in Japan – start re-using this chemical since it, and many other companies stopped in 1980? Yes, they did actually stop, and only restarted in 2005.

Well, it seems there may be two reasons.

Firstly, they believe they’ve found a method of getting the chemical’s benefits, yet only using a minute amount, which wont cause health concerns as it shouldn’t end up in the final product on the shelf, as it is only used in the production process.

Secondly, but slightly more troubling, a blog article, from a fairly well regarded blog, suggested it was more interested in sticking to it’s founding family’s traditional recipe- [link].

However, to take the first concept – a quick Google through Yamazaki’s website threw up two real hits on potassium bromate – one a gnarly white paper from 2004 entitled “The study of bromate residues in bread Part1 – Effect of Reducing Agents and Baking Procedure on the Residual Bromate in Bread” (no longer on their website it seems),  and the second in their investor guide (also since removed).

From the whitepaper, the English summary states:

“Potassium bromate, which contributes to the formation of disulfide bonds in wheat protein in dough and increased gas-retaining capacity, has been used as a bread improver since the 1910s.  However, it has been reported that potassium bromate has a mutagenicity based on experiments with rats. Thereby, the regulations in Japan stated that in the case of bread, residual bromate must be reduced or removed from the final products.”

So that essentially lays out the ground rules as Yamazaki saw them, in their own words – the key point seems to be final products. The summary goes on:

“Residual contents of potassium bromate in bread extracts prepared by the improved method were measured by high performance liquid chromatography (HPLC) with post-column reaction for the coloring of bromate. No residual bromate was detected in Pullman-type breads with +- or +/mg potassium bromate added per kg of flour.”

As a note of explanation, a Pullman loaf is one baked in a long narrow tin, with a lid – that is, pretty much all of the square sliced bread in Japan. The summary goes on to note that:

“On the other hand, the residual bromate determined in open-top type bread with 9-30 mg potassium bromate added per kg of flour, was found localized on the top of crust put out of the baking pan.    Reducing agents such as L- ascorbic acid (AsA), cysteine and glutathione and ferrous sulfate were added to the open-top type bread to reduce the residual bromate. Adding both AsA and ferrous sulfate accelerated the decrease in the residual bromate in the open top-type bread.”

I’m not a scientist but, what they’re saying is, they have to do this to say there shouldn’t be any Potassium Bromate in the bread after they’ve added even more chemicals. In 2005, the FDA in America noted as a post (co-authored by Yamazaki) detection techniques for Potassium Bromate which is an important requirement if something is only legal up to minute quantities in a baked product.

This seems to be a lot of trouble to go to to keep using a chemical largely frowned upon internationally, and which according to their competitors, there are acceptable alternatives available to, which suggests that the second point – because it’s a tradition – starts to seem all the more plausible?

Well, for another angle, let’s look at that second hit, the 2008 investor guide, from the section “Fiscal 2008 in Review” which generally paints a dismal economic picture :

“To maintain top levels of product safety and quality, despite the soaring cost of ingredients, particularly flour, we had to execute another round of price increases. Even though we had only just increased prices on some of our breads and Japanese- and Western-style confectionery in December 2007, we had to push through more increases in May 2008. Hoping to make the new prices more palatable to consumers, we emphasized the quality aspect of our products by applying a new technology to Pullman – type bread using an aqueous solution of potassium bromate as an oxidizing agent, and then, the technology were applied to Open-top bread and sweet buns.”

So there’s an economic justification too? I appreciate investor guides are dry tomes intended to attract funds and other interested parties into buying shares, bonds, whatever, but this is an interesting tack to take on what is I would have thought, a sensitive subject.

For a ‘defence’ of the use of Potassium Bromate, I had to go to The American Institute of Baking (AIB), (which also has a Japanese site amateurishly done in Adobe GoLive 5) and their paperCommercial Baking Industry Guide For The Safe Use Of Potassium Bromate” [2008] but even they don’t seem overly confident. Though this is obviously a bit of a weak stance as an opener in the paper:

“Potassium bromate (KBrO3) has been used in limited ways and amounts by the baking industry for almost a century with no known health concern. It has been used in baking since at least 1914 …”

I’m not sure I put a lot of faith in something being safe since before penicillin, and decent analysis methods. However, they do go on:

“Concern about the potential harmful effects of potassium bromate was raised by Japanese researchers in the mid-1980s. While the research was inconclusive, some countries adopted a precautionary-principle response and removed potassium bromate from the approved list of dough conditioners. More recent research in Japan casts doubt on this level of concern, at least as it refers to the amounts of potassium bromate used in the baking industry, concluding that there is a threshold below which no adverse effects can be detected.”

I’m wondering if the more recent research was by Yamazaki Bakery. The paper does immediately point out though, and with it’s own bold emphasis:

“It is recognized that it is inappropriate to use potassium bromate in any product or production method which cannot be formulated without residues below the level of 20 ppb in the finished product.”

That’s not really a huge endorsement to me. However, the paper does a decent job, in basic terms explaining the reason why Potassium Bromate is used, and for that, the PDF is worth a download, and at 15 pages of text, worth a read.

So what we have is a chemical known to cause renal cancer in rats, at least, and which is controlled by amount in foods, or outright banned in many countries, and yet Yamazaki Bakery here in Japan have gone to a lot of effort to use it in their production system – again, I’m not saying it’s in the bread – it shouldn’t be – but why even use it? Is it really because old man Iijima did? Then the question becomes, if he were alive today, would he still use it?