Preparation and characterization of nano-selenium stabilized with starch nanocrystals and ferulic acid and its application in the preservation of zaosu pear

Traditional SeNPs are significantly limited by deficiencies in stability and biological activity. In this study, we optimized the structure and biological activity of SeNPs by incorporating starch nanocrystals (SNCs) and ferulic acid (FA). Subsequently, we characterized the structure of FA-SNCs-SeNPs through techniques such as scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Finally, we investigated the preservation effect of FA-SNCs-SeNPs treatment on postharvest Zaosu pears by integrating it into a starch/gelatin composite film system. The results indicated that the particle size of 0.27 g/mL FA-SNCs-SeNPs was 604.45 nm, exhibiting optimal stability with a 6.28% increase in the absolute value of zeta potential. Compared to SeNPs, the thermal stability and oxidation resistance of FA-SNCs-SeNPs improved by 30% and 26.2%, respectively. Moreover, the texture of the S/G/FA-SNCs-SeNPs was more uniform, exhibiting a 4.41% reduction in water vapor permeability, a 30.84% enhancement in elongation at break, and decrease in colony diameter of P. expansum and T. roseum by 13.1 and 23.2 mm, respectively. Additionally, the DPPH scavenging rate increased by 5.8% at a concentration of 100 mg/mL, when compared to the starch/gelatin film (S/G). After applying the coating treatment to Zaosu pear, S/G/FA-SNCs-SeNPs exhibited significant antifungal and antioxidant effects, effectively delaying the yellowing process, inhibiting respiration, reducing weight loss, and maintaining storage quality parameters such as soluble solids content, hardness and brittleness. This study presents a novel approach for the application of SNCs in the synthesis of selenium nanoparticles.