Quick removal of persimmon astringency by medium high hydrostatic pressure treatment

M. Sugiura, T. Suzuki, T. Niikawa, H. Ogino, T. Imaizumi
Medium high hydrostatic pressure (MHHP) treatment is a technique for achieving sterilization, component modification, liquid impregnation, etc., which has become popular in recent food processing. In this study, the astringency of persimmon was removed by the MHHP treatment (100 MPa, 25°C, 240 min). Then, the cells of ‘Hiratanenashi’ treated with the MHHP were observed by using an optical microscope. Although the tannin cells of the fruit removed astringency by carbon dioxide were coagulated, the MHHP treatment seemed to rupture the cells and discharge the intracellular contents. In addition, the impedance characteristics of the MHHP treated fruits also indicated that the treatment probably damaged the cell membrane. To clarify the mechanism of astringent removal, soluble tannin contents were analyzed by the protein precipitation method and the Folin-Denis method. In addition, since the treatment reduced the soluble tannin content obtained by the Folin-Denis method, tannin might be adsorbed on fragments of cell walls and cell membranes. The results suggested that these factors were associated with removing astringency in persimmon fruit by the MHHP treatment.
Sugiura, M., Suzuki, T., Niikawa, T., Ogino, H. and Imaizumi, T. (2022). Quick removal of persimmon astringency by medium high hydrostatic pressure treatment. Acta Hortic. 1338, 351-356
DOI: 10.17660/ActaHortic.2022.1338.50
tannins, impedance characteristics, Folin-Denis method, protein precipitation method

Acta Horticulturae