Vol. 3, Issue 5 (2018)
Astringency removal in persimmon fruits (Diospyros kaki L.) cv. “Hachiya” treated with CO2 and ethanol
Author(s): Naveen Kumar, KS Thakur, Stish Kumar, Kavita Devi
Abstract: The study was carried out during the year 2016 season on "Hachiya" persimmon fruits as an astringent variety. The fruits were treated with CO2 gas and ethanol vapour treatment and stored under normal atmospheres for 9 days. Fruits were analysed for firmness, total tannins, total soluble solids, titratable acidity and rate of respiration after treating and stored at ambient conditions. CO2 deastringency treatment carried out with a high CO2 concentration (>80 %) in a HDPE bags containing fruits for 8, 16 and 24 h at ambient temperature whereas, ethanol vapour treatment was applied as treating the fruits with ethanol solution @ 10, 20 and 30 per cent in desiccator for 24 hours and after the treatment fruits were packed in brown paper bags and stored at ambient conditions. Ethanol dip treatment was also tried as a dipping the fruits in 10, 20 and 30 per cent solution of ethanol solution for 15 minutes. Astringency removal treatment caused an immediate increase of acetaldehyde and ethanol, nearly to the same extent as in conventionally ripened or stored fruit. The amount of soluble tannins, the main cause of an astringent taste, decreased during storage, and it did much faster with CO2 (> 80 %) treatment for 24 h. The physico-chemical test revealed that fruit treated with high CO2 was preferred to conventionally ripened fruit.