煎茶浸出液の褐変に関与する水溶性成分について
1982 年 1982 巻 55 号 p. 80-82
詳細
1982 年 1982 巻 55 号 p. 80-82
Green tea infusion was fractionated into 6 fractions by successive extractions with 3 kinds of solvents (chlorofom, ethyl acetate and n-butanol) and by use of cation and anion-exchanger columns. The aqueous solution of a single fracfion or the combined solution of 2 or 3 fracfions was heated at 80°C for 20 hours, and the degree of browning of the heated solution was examined by measurement of the absorbance at 450nm.
The ethyl acetate fraction showed the most remarkable browning, followed by the n-butanol fraction. The browning of both the fractions comprised about 50% of the whole browning of tea infusion. When the cationic fraction was added to the ethyl acetate fraction, the browning of this mixture increased to about twice that of the ethyl acetate fraction alone. The mixture of the ethyl acetate, the n-butanol and the cationic fractions took part in above 90% of the browning of tea infusion.
