Application of nanoparticles blue-TiO2-x and chitosan coating to delay ripening and suppress ethylene-related gene expression of Cavendish banana

Abstract

Cavendish bananas are climacteric fruits that rapidly respond to biochemical reactions during ripening. Therefore, it quickly undergoes a decrease in commercial value during post-harvest storage. This study evaluated the effect of Fruit Storage Chamber (FSC) modification on the photoactivation of nanoparticles blue-TiO2-x and 1.25 % (w/v) chitosan coatings on the physicochemical and molecular characteristics of Cavendish bananas stored at a low temperature (22 °C). The results showed that the combination of FSC treatment supplemented with nanoparticles blue-TiO2-x and bananas coated with 1.25 % (w/v) chitosan can maintain fruit quality during seven days of storage at 22 °C, compared to the control. Applying both of nanoparticles blue-TiO2-x variants with chitosan-coated bananas can suppress the relative expression of the MaACS1 gene until the 5th day but lead to an up-regulated expression on the following day. However, the control sample stored in FSC with nanoparticles blue-TiO2-x was the best treatment to suppress relative MaACS1 (Musa acuminata ACC synthase 1) and MaACO1 (Musa acuminata ACC Oxidase 1) gene expression in the pulp until the end of shelf life. It means the treated sample with 1.25 % chitosan could suppress MaACO1 gene expression six times more than a banana without chitosan while in storage without FSC. MaACO1 expression in nanoparticles blue-TiO2-x bananas coated with 1.25 % (w/v) chitosan decreased 28-fold during storage 7 days. This study suggested that a 1.25 % chitosan coating combined with storage in FSC with nanoparticles blue-TiO2-x can inhibit ACC oxidase from converting ACC to ethylene. This study demonstrated that an FSC equipped with nano-TiO2 variants, low temperature, and 1.25 % (w/v) chitosan coating is a promising solution that could delay ripening and extend the shelf life of Cavendish bananas.