Bioscience Methods 2025, Vol.16, No.2, 70-82 http://bioscipublisher.com/index.php/bm 71 With the continuous advancement of technology, separation efficiency and product functionality are gradually improving, and the economic value of starch and gluten is also increasing. This study will systematically review the development history and latest achievements of these new technologies, with a focus on innovation in separation processes, new ideas for functional modification, and emerging applications in the food, pharmaceutical, and new materials industries. I hope that through these analyses, we can provide reference for the industry on the current challenges, technological breakthroughs, and future trends related to wheat separation, and help promote the sustainable and high value-added development of wheat processing. 2 Composition and Structural Characteristics of Wheat Starch and Gluten 2.1 Structural characteristics of wheat starch Wheat starch is the primary carbohydrate component in wheat flour, and its granules are mainly composed of a mixture of two polysaccharides: amylose and amylopectin. The ratio of these two polysaccharides affects the functional properties of starch, such as water absorption, swelling power, and gelatinization. Li et al. (2020a) found that high amylose wheat starch (HAWS) has a higher content of amylose and a lower degree of branched starch chain branching. It has a more linear molecular structure compared to ordinary wheat starch, manifested by stronger HAWS viscosity and stability. Due to the looser arrangement of polymers within the granules, HAWS also shows stronger water absorption capacity. The crystalline structure of wheat starch is generally classified as A-type, which is characteristic of amylose. This structure is marked by relatively weak crystallinity and poor water solubility; however, it remains stable even under treatments such as ultrasonication (Karwasra et al., 2020). Karwasra et al. (2020) suggested that the A-type crystalline structure of wheat starch contributes to its relatively high gelatinization temperature and distinct pasting properties, which ultimately affect the quality of wheat-based products. During processing, the surface properties of wheat starch granules - including surface lipids and proteins - influence the ease of starch separation. Furthermore, after processing, the relative crystallinity of starch may change, which further affects its functional properties such as swelling power and oil absorption capacity (Wang et al., 2021). 2.2 Composition and functional properties of wheat gluten Wheat gluten is a protein complex primarily composed of two types of proteins: glutenin and gliadin. It also forms the viscoelastic network essential for the unique dough properties of wheat flour. Gliadin and glutenin provide complementary functional properties, jointly determining the extensibility and elasticity of the dough. Meanwhile, their ratio significantly influences the pasting properties, thermal stability, and structural characteristics of gluten-starch mixtures. Furthermore, changes in the glutenin-to-gliadin ratio also alter the viscosity and thermal stability of the mixture, ultimately affecting the quality of wheat-based products (Li et al., 2020b). The functional properties of gluten, including extensibility and elasticity, largely depend on its protein structure. For example, the disulfide bonds within gluten and the secondary structures of its proteins, such as α-helices and β-sheets, together determine its ability to form a network. This protein structure can be modified through mechanical, chemical, or enzymatic treatments. Liu et al. (2021) found that physical modification methods, such as planetary ball milling, can disrupt the natural structure of gluten, reducing its particle size and decreasing its crystallinity. These structural changes further alter the surface hydrophobicity and foaming capacity of gluten, expanding its potential applications in food products. 2.3 Interfacial binding mechanism between starch and gluten Starch granules are embedded within the gluten network, forming a complex structural matrix that ultimately affects the physical properties of the dough. Therefore, the interaction between starch granules and gluten proteins is one of the key factors determining dough properties. The particle size distribution of starch granules, particularly the ratio of A-type to B-type granules, significantly influences this interaction. Studies have shown that the higher the B/A/porosity ratio (i.e., the greater the proportion of B-type granules), the more stable the dough tends to be, which is attributed to the closer binding between starch granules and the gluten network (Gao et al., 2020; Yu et al., 2021). Figure 1 compares the starch granule morphology and gluten network formation characteristics of three wheat varieties: Xinong 979, Zhengmai 7698, and Xinong 836. When the starch granules
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