Ultrasonication as a tool to develop starch nanoparticles from macrophytes to tailor starch properties

Abstract

Starch is a popular type of biopolymer that has multiple uses in industry and there is an increased interest in searching the possible sustainable sources in underutilized plants. The paper was aimed at extracting and characterizing starch from macrophyte narrowleaf cattail (Typha angustifolia) and lotus (Nelumbo nucifera) of Dal Lake, Kashmir. The two species possessed high starch content of 67.11 ± 1.03 % and 66.18 ± 1.04 % with moderate amylose content of 13.67 ± 0.70 % and 13.45 ± 0.11 %, respectively, indicating their alternative use in the food industry. Proximate analysis showed that cattail starch contained more protein (6.28 ± 0.55 %) and fat (2.15 ± 0.03 %) than lotus, indicating that the two species are functionally different and may be applied in specific functional applications. Ultrasonic processing, a green efficient method was used where the acoustic cavitation by high frequency sound waves improved mass transfer and destruction of plant cell walls, leading to structural changes in the extracted starches thereby enhancing the functional and physicochemical properties. Ultrasonic nano-reduction minimized particle size and improved the colloidal stability of the particles as shown by the low polydispersity index and high negative zeta potential. Such physicochemical improvements would increase starch functionality in biodegradable packaging, pharmaceutical, and food technology applications. This study identifies the untapped potential of macrophytes from Dal Lake as renewable sources of biodegradable starch, encouraging the sustainable use of local biodiversity and valuable addition products, which boosts the economic growth of the area.