Ethylene scavenging properties from hydroxypropyl methylcellulose-TiO 2 and gelatin-TiO 2 nanocomposites on polyethylene supports for fruit application

Several technologies have been proposed to preserve fruits and to avoid postharvest losses. The degradation of ethylene produced by the fruits using TiO photocatalysis has shown to be a good option to delay the ripening of fruits. This paper proposed a new application of biopolymers-TiO nanocomposites developed to extend the shelf-life of fruits. Photocatalytic coatings were applied on the expanded polyethylene foam nets to degrade ethylene. Gelatin and hydroxypropyl methylcellulose (HMPC) were tested as hydrophobic and hydrophilic matrices for the TiO incorporation. First, nanocomposite films prepared by casting were evaluated with regards to their photocatalytic properties. Both matrices, which were loaded with 1 wt% TiO , degraded 40% of the ethylene injected in a batch reactor. By Langmuir-Hinshelwood model, ethylene degradation using gelatin-TiO films (k = 0.186 ± 0.021 min ) was faster than the HPMC-TiO films (k = 0.034 ± 0.003 min ). Then, gelatin-TiO dispersion was applied as a coating on the foam nets by dip coating. The gelatin-TiO bilayer exhibited higher concentration of ethylene degraded per photocatalytic area and photocatalyst mass unit (13.297 ± 0.178 ppmv m [Formula: see text] ) than its film form (18.212 ± 1.157 ppmv m [Formula: see text] ), which makes gelatin-TiO /foam nets a promising composite design for fruit postharvest application.