Astringency reduction using ethanol-associated to the storing under refrigeration at 5°C promotes physiological and structural alterations in 'Giombo' persimmons

This study aimed to study the effect of astringency reduction using ethanol and application of 1-MCP in 'Giombo' persimmons, storage in cold chamber at 5°C and to assess its physiological and structural alterations. After the deastringency treatment using ethanol, and the application of 1-methylcyclopropene (1-MCP), the fruits were stored at 5°C and 90% RH during 60 days and shelf life (SL) for 5 days at 22°C. The dosage of 1.70 ml/kg^(-1) ethanol during 12 hours was efficient for the astringency removal in 'Giombo' persimmons. However, deastringency using ethanol reduces pulp firmness and 1-MCP preserves this characteristic both in detannized fruits and in controls. The increase of soluble pectins and solubilization did not foster the polymerization of the soluble tannins both in control and detannized fruits. 'Giombo' persimmons displayed a severe firmness reduction, increase of soluble pectins, and degradation of the parenchyma cells, gelling of the pulp, increase of the production of ethanol and acetaldehyde after 60 days of storing + 5 days SL, inclusively in control fruits, and those treated with 1-MCP. These results suggest, cultivar 'Giombo' is susceptible to damages at 5°C and that further studies are required using different temperatures to improve the storage.