Postharvest Physicochemical Properties and Fungal Populations of Treated Cucumber with Sodium Tripolyphosphate/Titanium Dioxide Nanoparticles during Storage

Abstract

Cucumbers have a limited shelf-life, from 10 to 14 days at commercial temperatures with relative humidity (80%). The aim of the work was to evaluate the postharvest physicochemical properties and fungal populations of cucumber treated with sodium tripolyphosphate/titanium dioxide nanoparticles during storage at 10 °C to prolong the shelf-life to 21 days. Cucumber samples treated with chitosan/sodium tripolyphosphate/titanium dioxide nanoparticles (Cu-CHS-TDN-ST) and (Cu-CHS-TDN-ST) were found to be in a well-hydrated state and with a green-colored appearance upon day 21, with excellent quality for consumption. Chitosan coating (Cu-CHS) alone prolonged the cucumber shelf-life for 14 days of storage. The Cu-CHS coating was less evident in reducing the respiration rate of cucumbers on day 14 than both nanocoatings, which were reported at the end of the storage period to be 5.09 and 5.38 mg·kg−1 h−1 for Cu-CHS-TDN-ST and Cu-CHS-TDN, respectively. The Cu-CHS-TDN-ST treatment reduced the loss of ascorbic acid content to 13.17 mg/100 g, delayed chilling injury, and had the highest chlorophyll contents during the whole storage period. The presence of sodium tripolyphosphate with the nanocoating delayed tissue damage. Peroxidase enzyme activity reached the maximum of 54.65 Ug−1 for Cu-CHS-TDN-ST on day 21, followed by Cu-CHS-TDN 50.1 Ug−1. On day 21, the fungal populations of Cu-CHS-TDN samples (3.77 log CFU/g) were more than that of Cu-CHS-TDN-ST (3.15 log CFU/g) against Cu-Control (100 % spoiled). It was noted that the Cu-CHS-TDN-ST and CHS-TDN-ST coating treatments were capable of preserving the cucumber samples’ quality during storage. The addition of sodium tripolyphosphate as a crosslinker for stabilizing the nanoparticle polymers in the coating treatments prolonged the shelf-life and achieved excellent quality for the cucumbers.