Fractionation of tomatoes
Tomatoes were cut into quarters, and each piece was divided
into peel, flesh and residue. Each fraction was homogenized and filtered
with membrane filter (0.2 lm pore size). The filtrate was
used as the extract of tomatoes, and the volume of the extract used
for WST-1 assay was from 2 to 10 lL in 100 lL of Medium B.