Corn Flour: Production, Types, Properties and Uses in Baking

Corn flour is the simplest and most obvious way to use corn as food, yet for a long time it found only modest and limited use — confined to a handful of traditional dishes such as mamaliga, polenta, lemishka and the like.

Corn flour was not used at all in baking bread or in making flour-based confectionery. The reason, of course, was not a dislike of corn flour but the difficulty of milling corn, its chemical composition and the technological properties of the flour. An inability to use corn flour effectively also played an important role here.

What difficulties limited the production of corn flour?

The main obstacle to producing and using corn flour was the presence in the corn kernel of a large, hard-to-separate corn germ. Unlike all other cereals, the germ in corn makes up 10–12% of the kernel's weight, which greatly complicated milling.

The corn germ is also the source of the rancidity problem. When the germ or part of it ends up in the flour, the flour goes rancid: the corn germ contains on average 30–40% fat, whereas the whole kernel contains only 4.5–6% fat.

The chemical changes in fat that occur during flour storage are mainly oxidative, leading to rancidity and spoilage. In this case the well-known saying "you can't spoil porridge with butter" proves entirely wrong — the more fat the flour contains, the more prone it is to spoilage, and therefore the lower its quality.

The second factor that hindered the use of corn flour in baking is its chemical composition, and in particular the properties of corn proteins. These difficulties in producing corn flour are real, yet people have learned to work around them. New milling schemes and the use of different types of corn now make it possible to obtain ordinary baker's flour, confectionery flour — both white and yellow — children's flour and pancake flour.

What types of corn flour are produced?

Different milling processes yield several distinct grades of corn flour, each intended for a specific use:

• Baker's corn flour is used in bread-making as an addition to wheat flour (discussed in more detail below).
• Confectionery flour, as its name makes clear, is intended for flour-based confectionery such as cakes, biscuits, sponge cakes and pastries.
• Children's flour is the highest-quality grade — it contains 90–95% starch.
• Pancake corn flour is intended for use as an addition to wheat flour in the pancake mixes produced by the food-concentrate industry.

Across all the milling schemes, the combined yield of flour and groats comes to 70%. The table below shows clearly how much of each product is obtained from the various types of corn (as a percentage of the kernel).