Composite Flour

1. What are composite flours (CFs)? What are they developed and produced for? Tuberous plants rich in starch such as cassava, yams and sweet potatoes that grow in the dry regions of the world are not suitable for making conventional baked products on their own, but they can be put to good use in combination with wheat flour. This encourages the growing of local plant species, saves on hard currency and improves the supply of protein to the population.
2. What is the difference between composite flours (CFs) and ready-mixed flours? Whereas ready-mixed flours contain all the durable ingredients of the recipe for a specific baked product, CFs are just a mixture of different flours from plants rich in starch and protein, with or without wheat flour, for certain groups of baked goods.
3. What baked goods can be made with CFs? In principle all baked goods can be made with composite flour, but the loss of quality with yeast-risen products is often considerable. Pastry goods, on the other hand,…

Dosage of Additives and Shelf-life of Bread

Dosage of Additives 1. The capacity of my mill is 100 tons/day. I want to improve the flour with ascorbic acid and enzymes. What options do I have? All! The improvers can be added separately or as premix, e.g. with middlings, using one or more micro-feeders of adequate dimensions. They can also be added in a batch process provided that a sufficiently large mixer is available.
2. We have to make a premix of flour improving agents with a carrier. What a carrier should we use? The best shelf-life of the premix is achieved with calcium sulphate or carbonate as a carrier, but both increase the ash content of the flour. Starch and soybean flour are also possible, but expensive. Flour or middlings are another option, the latter having better flow properties. If benzoyl peroxide (BPO) is to be used, the carries of choice are calcium carbonate, calcium sulphate or starch, because with one of the other carriers BPO would already lose part or all of its function in the premix.
3. We want to make a …


1. How can I replace potassium bromate, azodicarbonamide or ascorbic acid? The replacement of potassium bromate requires an oxidizing agent, e.g. ADA or ascorbic acid, and an enzyme that helps to soften the dough. The fast-reacting ADA can be replaced by mixtures of calcium peroxide and ascorbic acid. Ascorbic acid can only be omitted (in the absence of any other oxidizing agent) if limitations to baking performance are tolerated. Oxidizing enzymes such as glucose oxidase are not very effective in the centre of the dough unless the mixing process is performed at elevated air pressure or with the introduction of oxygen into the dough.
2. Why does benzoyl peroxide not succeed in bleaching my chappati flour (flour for flat bread, very high extraction rate)? Various explanations are possible : a. The dark colour of wholemeal flour is not only due to carotenoids with which benzoyl peroxide reacts. b. Because of the high concentration of pigments the BPO is exhausted before it achieves a bri…

Spectroscopic Methods

1. Why are spectroscopics methods used in cereal analysis? With the original gravimetric and chemical methods of analysis it was not possible to determine the properties and consistuents of grain mixtures of flour-and-water doughs reproducibly and quickly within the time in which it was possible to intervene in technical processes. NIR spectrometry has done away with these difficulties and shortcomings.
2. What does NIR stand for? The near-infrared (NIR) region is the wavelength range between 800 and 2,500 nm of the electromagnetic spectrum, i.e. a very dark red that is no longer visible to the human eye.
3. What is meant by NIR Spectrometry? The NIR procedure is a quick method by which individual components of a mixture of substances can be determined qualitatively and quantitatively. Constituents that contribute to the value of a product can be determined simultaneously within a few minutes and called up in sequence.
4. What is difference between NIR and NIT? The difference between re…

Question and Flour Problems (Extensograph and Alveograph; Guten Index and Glutomatic)

1.What is measured in an Extensograph and an Alveograph? These instruments measure the resistance of a dough to extension under controlled conditions. The shape of the curve shows the energy input (E in the Extensogram, W in the Alveogram). Different dough properties (short, normal, soft) and different protein levels (low, normal, high) are recorded.
2. How can the effect of flour improvers be measured rheologically? Of course baking tests are the analytical method for determining the nature and amount of the flour improvers to be added in the long term.
But extensogram data, especially, react extremely sensitively to all additives whose effects result from reactions with the proteins in the gluten. It was on the basis of such data that the theory of the Rheological Optimum was established and became acknowledged throughout the world. It gives concrete information on which flour improvers can be used to achieve which changes in the properties of the dough.
3. What is the difference bet…

Question and Flour Problems : Amylograph and Rapid Visco Analyzer; Farinograph and Cansistograph

Amylograph and Rapid Visco Analyzer 1.What does the Amylograph measure? The amylograph records the changes in the viscosity of a flour-and-water suspension caused by gelatinization of the starch during a controlled heating period. The Amylogram therefore shows the changes in water-binding capacity that take place during swelling and gelatinization and in the course of enzymatic and mechanical breakdown of the starch gel.
2. What is the connection between the Amylogram and the Falling Number? There is no direct connection between the Falling Number and the Amylogram data, but a mathematical/statistical orientation in the same direction does exist (if the number of measurements is large enough!). This should be checked for each new harvest.
3. What does a Rapid Visco analyser measure? The RVA is a “micro-amylograph” that combines the advantages of a small sample (2-4g) and the possibility of setting any desired temperature gradient. A distinction is made between a “stirring number” and “ra…

Question and Flour Problems : Rheology & Falling Number

1.What is rheology? Rheology is the branch of physics that deals with the elastic and plastic properties of systems and their flow characteristics. When combined with water, flour forms more or less viscous systems that solidify when baked. The science of rheology can provide information on quality in both states-baked and unbaked.
2. What are “basic rheological properties”? Basic rheological properties are the parameters strength, viscosity, elasticity and plasticity. They are determined by measuring the effects of deformation forces on the dough. These forces may be of any magnitude, and the measurements are correspondingly large or small. For the rheology of dough the most important properties are viscosity and elasticity.
3. What am I to make of the “flowery” descriptions of the properties of dough and baked goods that are so popular with bakers? The observations of experienced bakers and the resulting jargon are still very valuable for describing product attributes that may also b…

Question and Flour Problems : Storage (Wheat, Flour, Bread)

1.We noticed an increase in the temperature of the wheat to 45 0C in parts of the silo during the winter. When we checked the wheat we couldn’t find any signs of infestation. What may the reason have been? Can we still use the wheat? This phenomenon is probably due to self-heating caused by fermentation. This can occur if the wheat is not moved or sufficiently aerated during storage. If only a small amount is affected, the thoroughly mixed wheat can be used (unless the taste and smell are impaired), but the performance should checked. Unusually short dough properties indicate heat damage to a larger proportion of the wheat.
2. If the flour has been treated with enzymes/ ascorbic acid/ bleach, will its properties be maintained during storage? For how long? Most enzymes except glucose oxidase and transglutaminase are very stable in the flour too. In most cases the shelf-life is restricted by the organoleptic properties of the flour rather than by its baking performance. Ascorbic acid slo…

Question and Flour Problems : Colour

1.Although the ash content is only 0.5%, the flour has a dark colour. Why is that? There are wheat varieties with a higher pigment content (compare, for instance, U.S. Hard Red Spring Wheat with U.S. Hard White).
2. How can I brighten the colour of the flour? Chlorine, Chlorine dioxide (both are gaseous) or benzoyl peroxide (powder) can be used for bleaching. In contrast to chlorine and chlorine dioxide, benzoyl peroxide has almost no maturing effect on the flour. The treatment with benzoyl peroxide takes 24 – 72 h to become visible.
3. How can a brighter flour or bread crumb be obtained? A brighter flour can be obtained with a lower extraction rate, because the outer layers of the wheat kernel contain more pigments. Once the flour has been produced, treatment with chlorine and chlorine derivatives achieves a brighter colour, but is not acceptable in many cases for various reasons. The addition of benzoyl peroxide also results in a brighter colour, visible 24 -72 h after treatment of th…

Question and Flour Problems (Flour Components; Vitamins and Fortification)

1.What are the most important vintamins and minerals for flour fortification? The most important vitamins and minerals for flour fortification are folate and iron. Other substances often used are the vitamins B1, B2 and niacin, and also the mineral zinc. Vitamin A is only added to flour in a very few countries, possibly for reasons of cost.
2. What is the basis for the legal requirements in countries where fortification is prescribed by law? The legal requirements depend on the specific needs of the population in each country. These are determined in studies carried out by various organizations such as UNICEF, WHO and FFI. The FFI also recommends fortifying flour with at least iron and folate in every country.
3. How do vitamins and minerals react to storage? Vitamins are especially sensitive to heat, moisture, oxygen and light. Nevertheless, they can be stored for at least 1-2 years in the tightly closed original container in a cool, dry place (20 0C, 50% relative humidity). Minerals s…