## 3 Plant-Based Biopolymers
### Starch-Based VMAs  
Starch, a predominant dietary component, stands out for its diverse range and the versatility of its derivatives across various applications [35]. Serving as the principal storage polysaccharides in plant-derived foods, starches play an important role in global food production [36]. Approximately \(48\times 10^{6}\) tons are produced annually, with 70% of this output used in the worldwide food sector [36]. Indeed, it serves diverse functions including gelling, thickening, moisture retention, stabilizing, and texturizing in various food products. For instance, in cereal-based foods, starch significantly impacts texture by efficiently absorbing water and filling the dough matrix. Furthermore, derived from various plants (corn, cassava, sweet potato, wheat, and potato), starches exhibit varied characteristics such as in size, shape, and molecular organization, influenced by factors like plant species, genetics, and environmental conditions [37]. The extraction of starch from roots and tubers involves a systematic process, starting with grating the raw material to rupture plant cells and release the starch, followed by passing the fibrous material through sieves of varying mesh sizes and concentrating the resulting slurry through processes like decantation or centrifugation [38]. Starch, a polysaccharide [8], consists of two D-glucose polymers: amylose and amylopectin (Figure 8). amylose is characterized by its predominantly unbranched \(\alpha\) [1 \(\rightarrow\) 4] gluccan linkage while amylopectin features chains of \(\alpha\) [1 \(\rightarrow\) 4] linked glucose units organized in a heavily branched configuration through \(\alpha\) [1 \(\rightarrow\) 6] branching connections [39]. Furthermore, starch may contain minor constituents such as proteins and lipids [37]. Except for waxy starches with 100% amylopectin, the proportions of amylose and amylopectin vary depending on the starch source. Typically, starch consists of approximately 20-30% amylose and 70-80% amylopectin [8]. On the other hand, starch-based polymers, widely used in industries, such as in food and construction, can undergo crucial alterations through chemical, physical, or enzymatic methods from their native state [20], aiming to enhance positive traits and mitigate negative ones [40]. In addition, their modification can result in the development of innovative polymers with a range of functional and value-added properties to meet the requirements of various industries [40]. Moreover, both amylose and amylopectin can undergo these modifications, affecting granule arrangement and polymer structures. The precise controlling of modification conditions is thus essential for tailoring the properties of these modified starches, contributing to the development of innovative products across diverse industries [41]. Indeed, modified starches are also widely exploited in various construction applications, such as improving the adhesion of plaster to walls, minimizing settlement, providing initial strength, improving consistency, and optimizing rheological properties. For example, hydroxypropyl starch (HPS), a modified starch, has been used to optimize the material properties of construction products such as concrete and dry mortar [35]. It has been reported that the HPS with a degree of substitution (DS) of less than 0.5 and a dosage of 0.05% causes a rapid increase in viscosity, promoting the adhesion of plaster to walls. Moreover, when the HPS is combined with CE, it prevents plaster drips after spraying and reduces trovel stickiness. It is also used to reinforce tile adhesives and prevent water loss in porous formations [34]. In addition, starch derivatives improve the thickness and smoothness of cement-based formulations. Indeed, although their rheological characteristics under shear stress are undesirable, mortrs with starch derivatives are more viscous at rest.