Questions and Answers

Problems and Practical Solutions

Bread and rolls, biscuits, wafers or pasta: the production and processing of flour requires a high level of expertise

Under this heading you will find answers to questions we are often asked by our customers.

Can I use flour with 12 percent protein for making biscuits, crackers and wafers?

Although flour with less than 10 percent protein is preferable for many kinds of biscuits and wafers, you can often achieve good results with a higher protein content, too. If gluten forms during the process, the dough must be softened sufficiently; that can be done with reducing agents or enzymes, for example. With wafers, the protein has to be destroyed in order to prevent lump formation. In this case, a higher protein content results in products with a finer texture, less tendency to break and less water migration. But the protein content can also be reduced by replacing some of the flour with starch. However, it is only necessary to change the recipe in this way if you want a very tender, melting structure.

Which vitamins do wheat grains contain?

The main vitamins are B1, B2, B6, niacin and pantothenic acid; they are mainly present in the germ and the hull. The vitamins A, B12 and C are not present at all, and some others are only to be found as traces. Read more about our services in the section on flour fortification.

Are the vitamins in grain stable?

Yes, as long as the grain is undamaged. During processing at the mill, the vitamin content is reduced by the effects of atmospheric oxygen, light, temperature and other factors. Folic acid may be lost completely. In the case of baking flours, you should reckon with a loss of 70 to 90 percent. The higher the milling yield the higher the mineral and vitamin content of the flour.

What are composite flours? What are they designed and produced for?

Flours which, in addition to wheat, also contain other, non-wheat flours, are called composite flours. Maize, rice or tuberous plants like manioc, yams, cassava and sweet potatoes are rich in starch, but their flours are not suitable for the production of conventional baked goods when used on their own. They are, however, usable in combination with wheat flour. These blends are named composite flours. The purpose is to encourage the use of locally grown crops, reduce imports and save hard currency.

What is rheology?

Rheology is the study of the deformation and flow of matter under the influence of an applied stress. Together with water, flour forms more or less viscous systems (batters or doughs) that become solid when baked. Rheology permits an assessment of mechanical properties in both of these states – baked and unbaked. It delivers information on the viscosity, the extensibility, the elasticity and the resistance to an applied stress.

What conclusions can be drawn from the Falling Number?

The Falling Number describes the viscosity of a flour-and-water suspension heated to just under the boiling point with continuous stirring, Due to the heating, the starch gelatinizes. Indigenous or added amylases partially break down the starch gel. The viscosity is expressed as the time (in seconds) the stirrer takes to sink through the pasted starch gel at the end of the mixing period, plus the mixing time (60 s). Low Falling Numbers denote a broken-down gel. For many baking applications, Falling Numbers of about 280-320 s are favourable. A low Falling Number (< 250 s) is associated with a high level of amylase in the grain, and therefore indicates sprout or frost damage.

What effect do fungal amylases have on the Falling Number?

At the concentrations usual in flour treatment, added fungal amylases have little effect on the Falling Number since they are heat-labile and thus inactivated by heating. At over-dosage, the effects of fungal amylase also become visible in the Falling Number assay. With a modified model of the instrument used for measuring the Falling Number (final temperature adjustable) it is possible to determine fungal amylase at normal dosages.

How can I lower the Falling Number?

Although the use of classic fungal amylases improves the result of baking, it is not reflected in the Falling Number.

Only enzymes with a certain degree of heat stability, for example grain or bacterial amylases, have an effect on the conventional Falling Number method. Since most bacterial amylases are too thermostable (they would therefore survive the baking process and liquefy the crumb of the bread), grain amylases are generally used in the form of malt flour or malt four extracts. However, their effects on the baking results tend to be less predictable than that of enzymes from fermentation.

Mühlenchemie’s “Deltamalt FN” enzyme system offers an innovative solution. With the aid of this optimized fungal amylase it is possible to lower the Falling Number and at the same time improve the baking properties of the flours.

How can I raise the Falling Number?

The miller can increase the Falling Number by reducing the yield and hence removing the layers of the grain that contain the most amylase. The enzymatic activity of the amylase can also be reduced by adding flour improvers that alter the pH of the dough. Although a higher Falling Number may seem desirable because of specified flour properties, you should not forget to consider the baking properties of the flour and the quality of the end products.

What do I have to consider when using wheat with Falling Numbers below 200 s?

It should be mixed with wheat lots that have a higher Falling Number. The Falling Number of a mixture can be determined by the following method:

1. Calculate the Falling Number Index (FNI) of the two flours to be mixed and the desired Falling Number of the mixture according to this formula:

2. Calculate the mixing ratio of the two flours with the aid of the FNI, e.g. using the Pearson Square method or the following formulas:

PA and PB are the proportions (without signs) of flour A and flour B in the mixture, expressed as parts. Taken together, the parts constitute 100 %. Expressed as a percentage, the proportion of Flour A in the mixture would therefore be:

and that of flour B:

The mixture calculated in this way should be checked with the Falling Number instrument before being used at the mill.

Can I buy wheat with a Falling Number over 400 s?

Yes. Many wheat varieties from Australia and North America do, in fact, have an FN in this range. Their lack of fermentability can easily be made up for with enzyme preparations. However, it is wise to be sceptical about wheat lots from regions that do not normally supply wheat with a high Falling Number. In this case the high FN could be a sign of heat damage, for instance from excessive drying temperatures.

Do you have any other questions?