Astringency removal is one of the most important factors that influence ripening; improve quality and shelf life of persimmon fruits. So, this study was carried out to evaluate the efficiency of some chemical treatments like ethephon, ethanol, calcium carbide and saturated lime on removal astringency of fruits harvested at two dates and its influence on fruit quality parameters during shelf life at room temperature. Fruit harvested at two dates (50 and 75% color) were dipped in tap water for 5 days as control, saturated lime (Ca (OH)2 ) for 5 days, ethephon at 500 or 750 ppm for 5 min, ethanol at 25 or 30 % for 5 min and fruits exposed to gases resulted from mixing calcium carbide (CaC2) at 10 or 20g + 40ml water in closed chamber for 24 h and then stored at room temperature 23±1 °C and 60 ± 5 % RH for 15 days.
The obtained results showed that ethephon at 750 ppm for 5 min and calcium carbide at 20g +40 water had superior effect in reducing fruit weight loss %, decay %, total tannins and maintains firmness with increasing soluble solid content (SSC %) and enhancing ripening process than other treatments in both harvesting stages used. Since, these treatments were more effective to remove fruit astringency through reducing tannin content. In general, ethephon at 750ppm and calcium carbide at 20g treatments were effective in maintaining firmness, titratable acidity, ascorbic acid and soluble solids content in "Costata" persimmon fruits for 15 days of shelf life and removes the astringency. Moreover, the second picking date (75% color) was more suitable for maintaining the above mentioned quality characters.
Conclusively, it could be recommended to harvest Costata persimmon fruits at 75 % coloration and use one of the above mentioned treatments for removing the astringency with maintains the quality during shelf life.