# Utilization of the Nutritional Potential of Wheat Bran Using Different Fractionation Techniques
## 2 Cereals and Their Potential Nutritional Benefits  
Globally, cereals contribute to 60-70% of the human diet. They are also an important source of food for livestock and, last but not least, a small amount is processed industrially, for example, for biofuel production [16]. The table below (Table 1) shows the global annual production of the most important cereals. All cereals share the same common origin, which is reflected in the similarity in the structure of their grains and in their chemical composition (Figure 1). The table below (Table 2) compares the contents of the basic chemical constituents in the different cereals. \begin{table}
\begin{tabular}{c c} \hline \hline \multicolumn{2}{c}{**Annual Production (Million Tonnes)**} \\ \hline Maize & \textgreater{}1000 \\ Rice & 730–750 \\ Wheat & 730–750 \\ Barley & 130–150 \\ Sorghum & 60–70 \\ Millet & 20–30 \\ Oat & 20–25 \\ Rye & 10–15 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Approximate annual global production of major cereals for the period 2013–2022 [17]. Figure 1: Individual parts of cereal grain [18] (Reprinted with permission Ref. [18]. Copyright year 2015, copyright Onipe). The most important cereal for human nutrition in our cultural and historical circle is wheat, as was already mentioned in the Introduction of this paper. Wheat is processed primarily in the milling process into flour and secondarily for the production of bread, bakery products, and pasta. The wheat kernel consists of three main anatomical parts: the outer (and sub-coat) layers, the endosperm, and the germ. All three, but especially the outer layers and sub-coat layers, are a complex of several morphologically and histologically specific sub-parts. The wheat outer and sub-coat layers can be further sub-divided into three mains morphologically and functionally distinct layers, namely the pericarp, the testa, and the aleurone layer [18]. The aleurone layer is botanically the outer part of the starch endosperm, which is separated from the testa by a thin hyaline layer to which the cells of the aleurone layer are closely adjacent. Therefore, during milling processing, the aleurone layer is separated from the endosperm and separated together with the outer layers as part of the bran [20]. Wheat bran is rich in minerals, dietary fiber, B vitamins, and bioactive compounds, many of which have been shown to have health-promoting properties [18]. Bran is a by-product of the standard wheat milling process and has a global production of more than 150 million tonnes per year [16]. Bran has traditionally been a valuable component of livestock feed mixtures, but its surplus production is processed in different ways, often as a raw material for the production of alcohol or biogas, some of which is also used as fuel. Meanwhile, bran has considerable nutritional potential [11; 21; 22; 23]. Bran contains about 13-18% protein, 3-4% lipids, 3-8% ash, and more than 57% various carbohydrates (mainly hemicelluloses, cellulose, and 14-25% starch) [24]. If we compare the composition of the bran with the other parts of the grain, we obtain the following: the starch endosperm (besides available carbohydrates) consists of 15% lipids, 13% proteins, dietary fiber (0-5%), and ash (1-5%) [25], and wheat germ is rich in proteins (25%), lipids (8-13%), and ash (4-5%). Nutritionally attractive bran components include proteins or the aforementioned polysaccharides (dietary fiber components). The extraction of fiber components and their use and incorporation into recipes are currently receiving increased attention, not least because of the desire to reduce waste from conventional food and agricultural production. Fiber components are of particular interest because of their effects on the human body and its gut microbiome and the associated reduction in the risk of cardiovascular disease. This attractiveness is supported by health claims approved by the European Commission [23; 26].