Chemical modification of rice (Oryza sativa) and potato (Solanum tuberosum) starches by silanization with trimethoxy(methyl)silane

Rice starch of the A98 variety, with a denomination of origin of the state of Morelos, and potato starch were silanized to modify hydrophobicity and improve functional properties, providing added value to these starch sources and promoting their use in the formulation of biodegradable materials that require a degree of hydrophobicity, such as packaging materials. Fourier transform infrared spectroscopy analysis determined the presence of trimethoxy(methyl) silane in starch. Differential scanning calorimetry was used to determine the thermal properties and morphology was evaluated using scanning electron microscopy while changes in functional properties were assessed by identifying contact angle, swelling power, water absorption capacity, and oil absorption capacity. Hydrophobic silanized starches were obtained: Potato starch showed a contact angle of 132 ° and rice starch, 130 °. They exhibited changes in density and functionality; both swelling power and water absorption capacity were reduced in potato starch but increased in rice starch.

Keywords: Hydrophobic starch, hydrophobization, modified starch, A98 rice, trimethoxymethylsilane.