No abstract

To prevent the generation of drug-resistant fungi from long-term exposure to microorganisms, cinnamic acid (CA), a natural effective antifungal agent, was successfully coupled with poly-dopamine magnetic nanoparticles (CA-DMPs). Due to the low solubility of CA, the saturated solution of CA (1.61 mg/mL, 45 • C) had no antifungal effect. Contrarily, CA-DMPs showed a good antifungal effect. The resulting heatstable and reusable antifungal CA-DMP composite particles were superparamagnetic (49.79 emu g −1 ) and had an average diameter of 25.01 ± 1.36 nm. The novel composites showed good antifungal activity and excellent recycling performance, the sterilization rate of CA-DMPs remained above 96% after seven consecutive running cycles.CA-DMP composites could damage the fungal cell wall and membrane system, leading to the leakage of cell inclusions. Furthermore, transcriptome analysis of Aspergillus fumigatus treated with composites showed that 466 differentially expressed genes were primarily associated with cell wall membrane, membrane transporters, energy metabolism, genetic expression, and oxidation-reduction. The effect of CA-DMPs in inducing mitochondrial membrane dysfunction might result in the disruption of energy metabolism and REDOX homeostasis. Overall, the results reported herein provide new insight into the potential antifungal nanomaterials. In vitro antifungal experiments performed on cherry tomatoes confirm the application potential of the synthesized material in the field of fruit and vegetable preservation.

Hemerocallis citrina Borani as a low-cost vegetable, has various health benefits. However, the industry of H. citrina Borani is in the state of primary processing, with poor economic benefits. This study aimed to investigate the physicochemical properties, and the antioxidant activity of H. citrina Borani polysaccharide (HCBP) using subcritical water extraction (SWE) at different temperatures, to expand the value of H. citrina Borani. HCBP mainly composed of nine monosaccharides (glucose, galactose, rhamnose, fucose, mannose, arabinose, xylose, galacturonic acid, and glucuronic acid), among which the content of neutral sugar was higher and uronic acid was lower. HCBP contained glycosidic bond of β-configurations and trace quantities protein. The molecular weight of HCBP decreased with increasing temperature. Shear thinning occurred in HCBP with the increase of shear rate (0.01–1 s−1), and the apparent viscosity of HCBP decreased at higher temperature (150–160°C) with the increase continuously of shear rate (1–10 s−1), but almost remained constant at lower temperature (130–140°C). Scanning electron microscope showed that HCBP had rough surface, loose structure, obvious particle gap, and irregular shape. In addition, HCBP extracted at 160°C had strong FRAP activity, and HCBP extracted at 130 and 140°C had better ABTS radical scavenging activity. This study suggests that HCBP extracted by SWE could provide a cheap raw material as food thickening agent and natural antioxidants.