TY - JOUR
T1 - Antioxidant activity of plant extracts on the inhibition of citral off-odor formation
AU - Liang, Chia Pei
AU - Wang, Mingfu
AU - Simon, James E.
AU - Ho, Chi Tang
PY - 2004/9
Y1 - 2004/9
N2 - Grape seed, pomegranate seed, green tea, and black tea extracts were used to inhibit the off-odor from citral degradation. A 0.1 M citrate buffer (pH 3), containing 100 ppm citral and 200 ppm gallic acid equivalent plant extract, was incubated at 40°C. The reaction mixtures were analyzed by high-performance liquid chromatography (HPLC) at days 0, 6, 10, 13, and 16 to monitor degradation of citral and formation of α, p-dimethylstyrene, p-cymene-8-ol, and p-methylacetophenone. The addition of plant phenolic extracts could not inhibit citral degradation, however, all four plant extracts significantly inhibited p-methylacetophenone formation. The samples, with the addition of plant extracts, exhibited higher concentrations of α, p-dimethylstyrene and p-cymene-8-ol than the control. This is presumed to be due to the oxygen-scavenging effect of plant extracts blocking the pathway from p-cymene-8-ol to p-methylacetophenone. Our results suggest that these plant extracts act as general antioxidants inhibiting the generation of p-methylacetophenone regardless of the types of water-soluble phenolic compounds existing in the plant extracts.
AB - Grape seed, pomegranate seed, green tea, and black tea extracts were used to inhibit the off-odor from citral degradation. A 0.1 M citrate buffer (pH 3), containing 100 ppm citral and 200 ppm gallic acid equivalent plant extract, was incubated at 40°C. The reaction mixtures were analyzed by high-performance liquid chromatography (HPLC) at days 0, 6, 10, 13, and 16 to monitor degradation of citral and formation of α, p-dimethylstyrene, p-cymene-8-ol, and p-methylacetophenone. The addition of plant phenolic extracts could not inhibit citral degradation, however, all four plant extracts significantly inhibited p-methylacetophenone formation. The samples, with the addition of plant extracts, exhibited higher concentrations of α, p-dimethylstyrene and p-cymene-8-ol than the control. This is presumed to be due to the oxygen-scavenging effect of plant extracts blocking the pathway from p-cymene-8-ol to p-methylacetophenone. Our results suggest that these plant extracts act as general antioxidants inhibiting the generation of p-methylacetophenone regardless of the types of water-soluble phenolic compounds existing in the plant extracts.
KW - Antioxidant
KW - Citral degradation
KW - Off-odor
KW - Phenolic compounds
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U2 - 10.1002/mnfr.200400027
DO - 10.1002/mnfr.200400027
M3 - Article
C2 - 15497182
AN - SCOPUS:9944261289
SN - 1613-4125
VL - 48
SP - 308
EP - 317
JO - Molecular Nutrition and Food Research
JF - Molecular Nutrition and Food Research
IS - 4
ER -