Module 5 - Flour Q. What is the difference between Protein and Gluten? A. Wheat endosperm is basically a starch and protein matrix. Protein is always present in greater or lesser amounts depending on the wheat variety, growing conditions, etc. To assess the quality of the protein the starch can be gently washed away from a sample of ground endosperm (i.e. flour). The remaining material is referred to as wet gluten and is like chewing gum. Wet gluten can be assessed for extensibility, elasticity, and colour. The quantity of wet gluten can indicate whether wheat has been damaged by excess heat during drying and in some extreme cases the gluten may wash away. NB: Wet gluten content does not indicate protein content. Some high protein wheats may have little or no gluten and vice versa. On a commercial scale gluten can be separated, dried and ground into powder and then made available as dried vital wheat gluten for addition to breadmaking flours. Q. What does 'Flour Grade' mean? A. A finished flour is produced by blending together all or some of the individual machine flours being milled. Machine flours produced on the head reduction passages, during the early stages of the milling process, contain a high proportion of starchy endosperm from the centre of the grain. Machine flours produced further down the mill (on both break and reduction passages) contain progressively more of the outer layers of endosperm and branny material. The brown colour and high ash content of the bran cause the colour grade and ash content of the machine flours to increase down the mill. Because of this, most mills separate these machine flours into normally three grades, Top Grade (flour 1) consisting of head reduction flours Middle Grade (flour 2) consisting of mid reduction flours, Ibk, IIbk and BMR Low Grade (flour 3) consisting of lower break and reduction flours. Each of these grades can be treated differently due their different qualities. It is then possible to use a divide board to control which flour streams are fed into the finished flour or even divert each individual machine flour to a different grade collecting conveyor.   close window