This study presents a novel process to synthesize curcumin nanoparticles from fresh turmeric. An ultrasonic-assisted cajeput oil in water emulsion technique was used to synthesize nanocurcumin. The prepared nanocurcumin was spherical with an average size of 47 nm and size distribution of 5–80 nm. The synthesized nanocurcumin showed improved aqueous-phase solubility, and it was used as a reducing agent and stabilizer for biosynthesizing silver nanoparticles. Furthermore, the X-ray diffraction pattern of the silver nanoparticles showed four distinct diffraction peaks at 38.3°, 44.6°, 65.1°, and 78.1° corresponding to the lattice planes of face-centered cubic silver ((111), (200), (220), and (311)). Transmission electron microscopy analysis indicated the average size and maximum size distribution (80 %) of the silver nanoparticles were 10.9 nm and 5–15 nm, respectively. UV–visible spectroscopy measurement of samples indicated the localized surface plasmon resonance absorbance of an aqueous dispersion of silver nanoparticles at 406 nm. Zeta potential analysis revealed a negative charge with a magnitude of −27.2 mV, which indicated higher aqueous dispersion stability of the silver nanoparticles prepared from nanocurcumin. The nanoparticles showed antibacterial activity against Vibrio parahaemolyticus.

Mandarin (Citrus deliciosa Tenore) is one of the most important fruit crops grown in the Hue province, Vietnam, and has immense economic, health and cultural significance. However, mandarins are highly perishable and more susceptible to diseases compared to other citrus fruits. In the present study, biomimetic synthesis of silver nanoparticles (AgNPs) for preparing preservative solutions for mandarins was investigated. Spherical and nanometer-sized AgNPs that were prepared with the help of ultrasound wave induced a reaction between silver nitrate solution (AgNO3 0.02[Formula: see text]M) and the leaf extract of Centella asiatica. Spherical AgNPs were formed easily in the extract at an ambient temperature and their average size ranged from 3[Formula: see text]nm to 30[Formula: see text]nm. These AgNPs exhibited potent antifungal activity against Macrophoma theicola B1 fungi, which were isolated from mandarin peels collected from agricultural lands of rural villages of Thua Thien-Hue province in Vietnam. Thus, we are successful in preparing an AgNPs-containing preservative solution as a mandarin fruit-coating material to inhibit the growth of M. theicola B1 fungi. The coating of mandarin fruits with this preservative solution prolonged the storage life of the fruits from 9 to 35 days. On the 35th day, the preserved fruits maintained their natural color and ripening, whereas the control sample decayed with white fungus covering its skin after 9 days of storage. Thus, coating mandarins with this solution can be proposed as an additional treatment for increasing their postharvest quality. Additionally, it can be a solution for protection against fungal infection and physiological damage and controlling the decay of mandarins, thereby prolonging their shelf life.

No abstract

This research aimed to identify the possible effects of the moment of Aminoethoxyvinylglycine (AVG) application during near harvest period on ethylene biosynthesis and find out the most appropriate possible way to control the process for maximum prolonging the postharvest shelf -life of bananas. Results indicated that the most appropriate moment of AVG application is from the 74 th to 78 th days after formation of the last hand of a bunch has been finished as AVG showed some inhibition effects on ACC, ACC oxydase and ethylene synthesis. ACC, ACC oxydase and ethylene production of the fruits sprayed with AVG of 0.8 g/l on the 78 th day, harvested and stored at 13±1 o C for four weeks were 1.09 (nmol C 2 H 4 .g ) respectively while the ACC, ACC oxydase and ethylene production of non -treated fruits stored in the same conditions were 6.89 (nmol C 2 H 4 .g

Among soil pollutants, lead (Pb) is one of the toxic metal pollutants widely used in many industrial processes and occurs as a contaminant in environment. In this study, a field experiment was carried out to investigate the accumulation of lead from soil contaminated by this metal ion on the biomass of some vegetables, including spinach, lettuce, carrots, and potatoes. The results showed that lead was cumulative metal. Besides, the level of lead accumulation in soil of the studied vegetables decreased in the order of tubers of carrots, tubers of potato, spinach root, lettuce root, stems and leaves of spinach, stem and leaves of carrot, stems and leaves of potato, and stem and leaves of lettuce, respectively. Our investigations demonstrate the effect of copper and zinc micronutrient elements which play an important role in the growth and development of plants, on the accumulation of lead from contaminated soil of the studied vegetables. The obtained results showed that high concentration of copper and zinc in soil cause competition with lead in the process of absorption and accumulation in the plant. Specifically, copper and zinc showed the inhibition effect on the uptake and accumulation of lead by these plants.