Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Dairy Science

First Advisor

Srinivas Janaswamy


Essential mineral ions, Films, Starch digestibility


Essential minerals are indispensable inorganic micronutrients that modulate vital physiological functions at the molecular level. Their deficiency, though required in small amounts, impairs health significantly. Their supplementation through diet is prudent and carbohydrates standout as favorable choice. Carbohydrates, starches and polysaccharides, exhibit unique chemical structures and functionalities, and interact with mineral ions in several ways. The aim of this research is to investigate the effect of mineral ions on the physicochemical properties, tensile strength and in vitro starch digestion of starch-films. Corn starch and potato starch along with Fe2+, Mn2+, Cu2+ and Zn2+ ions have been chosen as model starch and mineral ions, respectively. The complexes have been prepared by treating 2% starches with 10% mineral ions. The X-ray powder diffraction and FTIR analyses confirm the starch-mineral complex formation. The maximum mineral loading is 56.5, 68.5, 44 and 15.7 mg of Fe2+, Mn2+, Cu2+ and Zn2+ ions, respectively, per gram of starch. The starch-mineral films have been prepared by mixing 1.4% (w/v) of starch, 0.1% (w/v) starch-mineral complex and 0.5% (w/v) sodium alginate in the presence of 1% (v/v) glycerol and casting films in a petri dish. The films are transparent, thin, flexible and homogeneous. The presence of Mn2+ and Fe2+ ions impart brownish to yellowish tint leading to higher color difference (Δ𝐸) and yellowness index (YI) and in turn lower the films transparency. The water solubility and moisture absorption increase substantially compared to the control starch films. The potato starch films possess higher water vapor permeability of 1.8 x10-10 gm-1s-1Pa-1 and tensile strength of 7.76 MPa and increase with mineral ions addition. The starch digestion increases with the presence of mineral ions. The outcome sets the stage for further research on mineral-carbohydrate complexes to develop novel functional foods and to mitigate the micronutrient malnutrition and improve nutritious living.



Number of Pages



South Dakota State University


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