LOX activity was measured using a continuous spectrophotometric
method based on that modified by Li and others
(2008). Hot water–ground soymilk was centrifuged at 16000 × g
at 4 ◦C for 15 min; the supernatant was crude enzyme extracts. A
portion of the crude enzyme extracts was inactivated in water bath
at 100 ◦C for 20 min, followed by full dissolution of 1 μL substrate
linoleic acid solution (99% purified, Tianjin, China) with 1
mL absolute alcohol by stirring. Subsequently, linoleic acid/ethyl
alcohol solution was diluted to 100 mL with borate buffer (pH 9,
0.2M).