Peeled and crushed potato (200g) treated at 100 degreesC for 30 min, rice k
oji (40g) and aqueous 35% (w/v) ethanol solution (100g) were used for makin
g potato mirin, a wine-like sweet seasoning. Antioxidative activity of pota
to mirin obtained after incubation at 30 degreesC for 45 days was examined
with both Rodan ferric method (as linoleic acid peroxidation) and beta -car
otene bleaching method (as BHA equivalent). (1) Linoleic acid peroxidation
in potato mirin (5% (v/v)), BHA (0.1% (w/v)) and commercial mirin (5% (w/v)
) was 2%, 12% and 110%, respectively. Compared with commercial mirin, the a
ntioxidative activity of potato mirin was very high. (2) BHA equivalent of
rice koji, peeled and crushed potato and potato mirin (218.5 g) was 14.3, 6
.0 and 213.2 mg, respectively, showing extremely high value in potato mirin
. That is, it was indicated that the antioxidative activity of potato mirin
was reinforced remarkably by incubation.