# Insight on Extraction and Preservation of Biological Activity of Cereal \(\beta\)-D-Glucans
## 3 Technological and Nutraceutical Value of Cereal \(\beta\)-D-Glucans  
In recent years, more and more attention has been paid to the bioactive components of foods and to the continuous research and implementation of functional and nutraceutical foods. The application of cereal \(\beta\)-D-glucans is desirable for a wide range of food products, as they can bring significant advantages both at a technological and health level [23]. In the food industry, cereal \(\beta\)-D-glucans are widely used in the preparation of beverages, sauces, soups, and other foods for their stabilizing, thickening, emulsifying, and gelling properties [15]. However, as extraction, handling, and upstream processing treatments pose a number of challenges, their use, particularly as a health ingredient, is still limited [7]. In fact, the incorporation of cereal \(\beta\)-D-glucans is restricted due to their high viscosity and industrial handling difficulties. Moreover, this problem is particularly evident when they are applied at concentrations sufficient to carry out their beneficial actions on the body [12; 13]. Therefore, it is important to consider the characteristics that fiber confers on final products when applied in large concentrations [24]. Just recently, cereal \(\beta\)-D-glucans were applied in different food matrices, such as couscos enriched with \(\beta\)-D-glucans from barley, meat emulsions, yogurt, whole meal, or oat bread, prebiotic sausages, fresh skimmed milk, fermented milks, oat bread and porridge, snacks, cow's milk, chicken breast emulsions, meatballs, and Asian noodles [10]. The addition of \(\beta\)-D-glucans in meat emulsions aims to increase fiber levels in the diet and, at the same time, achieve better technological results [10]. Carrageenan and starch are the hydrocolloids commonly used in meat products due to their technological properties. However, these ingredients have stringent maximum limits dictated by legislation, while the amount of extracted \(\beta\)-D-glucans that can be used in a food application depends on the characteristics of the matrix itself, and there is still no legislative consensus on the maximum and minimum amount of \(\beta\)-D-glucans that can be added to a given food matrix, nor on the procedures for applying \(\beta\)-D-glucans in each food group or category [10]. In liquid and semiliquid food matrices, such as milk matrices, the incorporation of high-MW oat \(\beta\)-D-glucans, an ingredient that promotes health and obtains low-calorie and cholesterol-lowering dairy products, has been widely studied. However, the thermodynamic incompatibility and phase separation caused by the interaction between milk proteins and \(\beta\)-D-glucans do not allow for the incorporation of an adequate quantity of \(\beta\)-D-glucans to perform health functions [25]. Indeed, mixtures containing a sufficient amount of barley \(\beta\)-D-glucans or oats required for health claims would show an undesirable appearance and texture due to the incompatibility between milk proteins and \(\beta\)-D-glucans [26]. Despite their consumption being associated with many health benefits, \(\beta\)-D-glucans in dairy products are used essentially as thickeners, prebiotic agents in yoghurt, or fat substitutes in reduced-calorie dairy products but not in functionally significant concentrations to fulfil health claims [23]. In addition to potentially being applied to a wide range of food products to improve texture, stability, and viscosity, it has also been shown that cereal \(\beta\)-D-glucans can be used to promote in situ folate synthesis (vit. B\({}_{9}\)) by specific yeasts and bacteria naturally present or added to the raw material [27]. In solid matrices, the addition of cereal \(\beta\)-D-glucans has been studied mainly for cereal products (bread, rusks, pasta, biscuits, sweets, etc.).