Development and characterization of nano starch-based composite films from mung bean (Vigna radiata)

The excessive use of disposable plastic material in our society demands packaging material which can undergo quick degradation without harming the environment. Agricultural products can serve as one of the essential sources for the production of biodegradable packaging material. In the present study, starch was isolated from mung bean and used for the synthesis of nano starch, and it's physicochemical, morphological, and film-forming properties were studied. The average particle size distribution of nano starch was 141.772 nm. Mung bean native starch granules were of oval shape having a smooth surface, free from cracks while mung bean nano starch appeared in an agglomerated form with irregular and rough surface. Nano starch-based composite films with varying concentrations (0.5, 1, 2, 5, and 10%) of nano starch were prepared by the solution casting method. The native starch film properties such as thickness (0.040 ± 0.010 mm), moisture content (8.03 ± 0.26%), water vapor transmission rate (5.982 × 10^-3 ± 0.30 g^-2 s^-1), water solubility (38.49 ± 0.51%) and burst strength (868.49 ± 26.5 g) were observed. With the incorporation of nano starch at concentration of 0.5 to 10.0%, film properties such as thickness (0.043 ± 0.006 to 0.063 ± 0.006 mm), burst strength (943.56 ± 18.1 to 1265 ± 18.9 g), moisture content (6.09 ± 0.28 to 4.80 ± 0.48%), water vapor transmission rate (5.558 × 10^-3 ± 0.25 to 3.364 × 10^-3 ± 0.35 g^-2 s^-1) and solubility (37.99 ± 0.47 to 34.11 ± 0.40%) were improved.