TY - JOUR 
A1 - Palou, Lluís
AU - Cerrillo, José L.
AU - Klangmuang, P.
AU - Pérez-Gago, María B.
AU - Taberner, Verònica
AU - De-La-Fuente, Beatriz
AU - Sothornvit, Rungsinee
AU - Rey, Fernando
AU - Valencia, Susana
AU - Palomares, Antonio E.
T1 - Curative activity against citrus postharvest green mold of composite hydroxypropyl methylcellulose-beeswax edible coatings with zeolites containing Ag-nanoparticles
Y1 - 2021
SN - 0567-7572 (print)

UR - http://hdl.handle.net/20.500.11939/8108
AB - Two types of commercial Na-zeolites, linde type A (LTA) and faujasite (FAU) were prepared with different percentage of silver that was incorporated by ion exchange using solutions of AgNO3. The physico-chemical properties of the samples were established using different techniques such as atomic emission spectroscopy with inductively coupled plasma (ICP-OES), X-ray diffraction (XRD), electronic microscopy (SEM and EDX), and temperature-programmed reduction (TPR). The curative activity of these materials was first evaluated as water dispersions in in vivo primary screenings by placing a drop (30 µL) in a rind wound of 'Valencia' oranges that had been inoculated 24 h before with a conidial suspension of Penicillium digitatum. Selected Ag-zeolites were incorporated as antifungal ingredients at different concentrations into composite hydroxypropyl methylcellulose (HPMC)-beeswax (BW) edible emulsions prepared with 8% total solid content with stearic acid as emulsifier and glycerol as plasticizer. Depending on the experiment, these coatings were applied 24 h after fungal inoculation to 'Valencia' oranges as drops in rind wounds or covering the entire fruit. Controls included inoculated but untreated fruit and inoculated fruit treated with HPMC-BW without Ag-zeolites. After incubation of treated fruit at 20°C for 7 days, coatings amended with Ag-zeolites reduced the incidence and severity of green mold by more than 80%, showing high potential for effective disease control. Curative activity depended on Ag concentration and FAU zeolites were more effective than LTA zeolites, probably because of their larger pore apertures and higher Si/Al ratio that favored silver diffusion. However, coatings with the highest silver content were phytotoxic causing dark blemishes on the fruit rind. Further work is needed to optimize non-phytotoxic coatings with the highest curative activity.
KW - Alternative postharvest disease control
KW - Nanotechnology
KW - GRAS salts
KW - H20  Plant diseases
KW - J10  Handling, transport, storage and protection of agricultural products
KW - Q02  Food processing and preservation
KW - Q03  Food contamination and toxicology
KW - U30  Research methods
KW - Penicillium digitatum
KW - Edible coatings
KW - Health foods
KW - Antifungal properties
KW - Zeolites
KW - Postharvest treatment
LA - en
PB - ISHS
ER -