DETERMINATION OF TIME EXPOSURE TO ETHANOL TO REDUCE ASTRINGENCY OF PERSIMMON ‘MIKADO’ (DIOSPYROS KAKI) FOR MINIMAL PROCESSING

The ‘Mikado’ persimmon is a very astringent fruit.
This fruit requires an adequate process to reduce its astringency and produce quality acceptable for minimally processing (MP). The objective was to evaluate the exposure time of persimmon to alcohol vapor (AV) 70% (7.00 ml alcohol kg^-1 fruit) to reduce the astringency of the fruit before fresh cut processing.
The experiment was conducted with fruits from the city of Sumidouro, Rio de Janeiro.
The fruits were transported to Embrapa Food Technology during the night to avoid high temperatures.
The fruits were collected during seven days.
At each harvest, fruits were selected, cleaned and subjected to AV at different exposure times.
The treatments were: T1-10 h; T2-36 h; T3-55 h; T4-83 h; T5-107 h; T6-130 h; and T7-155 h.
The fruit quality was evaluated through the following analyses: firmness, pH, total titratable acidity (TTA), total soluble solids (TSS), and total tannin contents.
Sensory analysis (SA) was also conducted to determine the detection threshold of astringency correlated with the concentration of soluble tannin in the pulp.
There was a decrease of firmness and soluble tannin concentration of the pulp with increased duration of exposure to alcohol vapor.
There were variations in the TTA and the TSS contents over time.
It was observed, through sensory analysis, that astringency was felt, by the panelists, up to 0.8161 μg 100 g^-1 of soluble tannin in the pulp.
Regarding the firmness of the fruit, the more appropriate exposure time, to AV, was 55 hours.
According to sensory analysis, the best time of exposure was 83 hours.
However, with 83 hours of exposure to AV the fruits firmness declined below acceptable levels for a product to be minimally processed.

XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on Postharvest Technology in the Global Market

A.C.V. Neves Junior , R.C.C. Coneglian, A.G. Soares, M.J.O. Fonseca , C.A. Alencar

astringency, quality, Diospyros kaki

https://doi.org/10.17660/ActaHortic.2012.934.72