were cut into quarters, and each piece was incubated with
100 mL of various aqueous solution, oil or paste at 7 C in the dark
for a fixed period. Each piece was homogenized after the incubation
and filtered with membrane filter (0.2 lm pore size). The
filtrate was used as the extract of immature green tomatoes, and
the volume of the extract used for WST-1 assay was from 2 to
10 lL in 100 lL of Medium B