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The role of polyphenol oxidase and peroxidase in the browning of water caltrop pericarp during heat treatment

Authors :
Ciou, Jhih-Ying
Lin, Hsin-Hung
Chiang, Po-Yuan
Wang, Chiun-C.
Charles, Albert Linton
Source :
Food Chemistry. Jul2011, Vol. 127 Issue 2, p523-527. 5p.
Publication Year :
2011

Abstract

Abstract: The mechanism of browning involving enzymatic browning was investigated in the pericarp of water caltrop, an Asian vegetable popular for its taste and medicinal properties. Polyphenol oxidase (PPO) and peroxidase (POD) activities were determined in pericarp at various times and temperatures. Water caltrop consisted of 44.22% moisture content, 37.23% crude fibre, and 2.63% crude protein. PPO and POD activities dropped from 62 and 38units/g sample, respectively, as water temperature was increased from 30 to 80°C. Optimum pH and temperature for PPO activity was at pH 5.0, 25–45°C, and POD activity peaked at 60°C. High PPO and POD activities at 40–50°C resulted in degradation of phenolic compounds, which led to increased aggregation of browning pigments and discolouration (lower L-values) of the pericarp. Enzymatic browning was determined as the major factor in the browning discolouration of heat-treated water caltrop pericarp. [Copyright &y& Elsevier]

Details

Language :
English
ISSN :
03088146
Volume :
127
Issue :
2
Database :
Academic Search Index
Journal :
Food Chemistry
Publication Type :
Academic Journal
Accession number :
58751151
Full Text :
https://doi.org/10.1016/j.foodchem.2011.01.034