Fabrication and Functional Properties of Curcuma Starch Nanoparticles as Affected by Different Degree of Polymerization of Debranched Curcuma Starch

Acetylated rice starch nanocrystals improved the physical, mechanical, and structural properties of native rice starch based films

Rice starch nanocrystals (SNC) and acetylated rice starch nanocrystals (ASNC) with three different substitution degrees (DS) for 0.22 (ASNCa), 0.56 (ASNCb), and 0.83 (ASNCc), respectively, were synthesized. Starch nanocrystals (SNC, ASNCa, ASNCb and ASNCc) with varying concentrations (0-25 %) were used in the production of composite rice starch-based films plasticized with glycerol using the solvent casting technique. Films were compared concerning their morphology, moisture content and solubility, transmittance, tensile strength, elongation at break. The SNC and ASNC content and acetylated DS had a significant effect (p ≤ 0.05) on all the properties investigated when compared to the control film. The addition of ASNC resulted in less hydrophilic films and UV light barrier properties, and the addition of SNC and ASNC increased the rigidity of starch film. There was an increase of 156.7 % in tensile strength for 10 % ASNCc composite films and a reduction of 68.1 % in water vapor permeability for 20 % ASNCc composite films. The rice starch/ASNCb nanocomposite films with the addition of 5 % and 10 % ASNCb exhibited a compact, smooth, and flat surface structure. Therefore, these results showed that ASNC significantly improved the mechanical properties, surface morphology and thermal stability of the films.

Acid Hydrolysis and Optimization Techniques for Nanoparticles Preparation: Current Review

Nanostarch is unique in that it is highly soluble, thermally stable, non-toxic and inexpensive. Hence, it is utilized in numerous well-established applications, including drug delivery, cosmetics, textiles, foods, and enhanced oil recovery (EOR). These applications take advantage of the special functions that can be achieved through modifications to the structure and properties of native starch. The most common method for the preparation of nanostarch with a relatively higher crystallinity and stability is acid hydrolysis. Technically, the properties of nanostarch are highly dependent on several factors during the hydrolysis process, such as the acid, concentration of acid, reaction time, reaction temperature, and source of starch. The production of nanostarch with desired properties requires a detailed understanding on each of the factors as they are inevitably affected the physical and chemical properties of nanostarch. Hence, it is vital to incorporate optimization technique into the production process to achieve the full potential of nanostarch. Therefore, the current review comprehensively elaborates on the factors that affect acid hydrolysis as well as the optimization techniques used in the preparation of nanostarch.