A look at flour from farm to plate
How does wheat become flour? There is a long process to turn tough wheat husks in to soft white flour. The nutrition content can be greatly affected by this process. If you want to get the most out of the flour and baked goods you choose at the supermarket, listen up closely.
Firstly, there are two kinds of wheat flours: winter (hard) wheat or spring (soft) wheat. Winter wheat is higher in protein and best suited for the use in breads1.
Wheat flours are also classified by the mineral and protein content. Whole-wheat flours receive higher classification because they are higher in fiber, vitamins and minerals because they retain the germ and bran1.
During milling (crushing the wheat in to powder) fiber and minerals are lost with the removal of the endosperm, germ and bran2. Approximately 45% of the protein, 80% of the fibre, 50-85% of the vitamins, 20-80% of the minerals and 99.8% of the phytochemicals are lost3.
Because parts of the wheat grain are removed, the resulting white flour has to be enriched with minerals due to the loss at milling1. Unfortunately the phytochemicals can not be restored3.
Any flour to be used in the manufacturing of baked goods must be fortified with folic acid (2-3mg/kg)4.
Bread is fortified with folic acid because it is a widely consumed food across all ages and economic populations4. Folic acid is essential for pregnant women or women who are planning to become pregnant to prevent their babies developing neural tube defects (NTDs)3.
The yeasts used in bread making also add B-complex vitamins, amino acids and minerals1.
Organic and non-wheat flours used for baked goods are not required to be fortified4 under FSANZ Standard 2.1.1 – Cereals and Cereal Products, so keep this in mind when weighing up the nutritional benefits of organic products.
The flour you purchase at the supermarket is also not required to be fortified unless it is a pre-made bread mix3.
Like all of the agricultural industry, herbicides and pesticides are used to protect crops. There has been much concern over the use of chemicals in our foods, leading many to choose organic products. Food Standards Australia and New Zealand (FSANZ) keep a careful watch over the use of these chemicals and deem that levels are safe to eat5.
Some consideration should also be given to the whitening treatments of refined flours. Whether it was initiated by consumers or manufacturers (the chicken or the egg argument), pure white flours gained preference over brown and ‘gritty’ flours. Hence treatments are applied to flours to increase whiteness and perception of purity.
Benzoyl peroxide (BPO), also used as an acne treatment6,7, is used in flour because of its properties in bleaching. It oxidises the yellow pigments of the carotenoids, whitening the flour6.
BPO may have some nasty side effects, such as breaking down in to harmful products and it may destroy essential nutrients such as vitamin A7.
A study on mice found that consuming 200mg of BPO per/kg of body weight, may cause liver damage6.
In Australia, the use of BPO is limited to a maximum amount of 50 mg/kg7. BPO has been used for over 50 years in bread and cheese making and is of no safety concerns when used at current levels7.
Flour and baked goods can make a great contribution to nutritional needs. Wholegrain products are strongly recommended over refined products due to possible health implications. But remember everything in moderation. Don’t be afraid to spread some avocado over that slice of wholegrain toast.
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- Brown, A. (2015). Understanding food: Principles and preparation. (4th ed.). Stamford, CT: Cengage Learning.
- FSANZ. (2014a). Standard 2.1.1. Cereals and cereal products. Retrieved from https://www.comlaw. gov.au/ Details/F2014C01190/Download
- Preedy, V., R., Watson, R., R., & Patel, V., B. (2011). Flour and breads and their fortification in health and disease prevention. Oxford, UK: Elsevier
- FSANZ. (2009). Australian user guide. Mandatory folic acid fortification: Implementing the requirements of the mandatory fortification with folic acid under standard 2.1.1 – cereals and cereal products. Retrieved from http://www.foodstandards.gov.au/Search/pages/results.aspx ?k=flour %20fortification
- FSANZ. (2014). Chemicals in food – maximum residue limits. Retrieved from http://www.foodstandards.gov.au/consumer/chemicals /maxresidue/Pages/default.aspx
- Jia, X., Wu, Y., & Liu, P. (2011). Effects of flour bleaching agent on mice liver antioxidant status and ATPases. Environmental Toxicology and Pharmacology, 31(3), 479-484. doi: 10.1016/j.etap.2011.03.009
- El-Samragy, Y. (2004). Benzoyl Peroxide: Chemical and Technical Assessment [Guidelines]. Rome, Italy: FAO. Retrieved from http://www.fao.org/fileadmin/templates/agns/pdf/jecfa/cta/63/Benzoylperoxide.pdf