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The antioxidant activity of Maillard reaction imxtrues mixtrues produced in the presence or absence of caffeic acid (CA) was studied, together with the color intensity and hydrogen donating ability (HDA) of the color intensity and hydrogen donating ability (HDA) of the mixtrues. The antioxidant activity of the mixtrures was investigated by comparing the peroxide values of soybean oil emulsions containing the mixtures with those of a control. The color intensity of the mixtures was determined by measuring the absorbance at 420 nm and the HDA by using 1.1-dipheny1-2-pycrylhydrazy1. The color intensities of the mixtrures, without and with CA, heated at 60, 80, and 100℃ were 0.014, 0.071, 1.061 and 0.103, 0.223, 1.603, respectively, whereas the HDAs were 0.007, 0.014, 0.034 and 0.204, 0.247, 0.360, respectively. The color intensities of the mixtures increased more rapidly than the HDAs as temperature increased. The color intensities and HDAs of the mixtures with CA were greater than thowe of the mixtures without CA at all temperatures used All the browning mixtrures exhibited antioxidant activity in the soybean oil emulsions. The addition of CA increased the antioxidant activity of the mixtures. The increase was significant at 5% level. The activities of the mixtrures formed at 100℃ were greater than those of the mixtures formed at 60℃. The difference was also significant at 5% level. The antioxidant activity seemed to depend more on the formation of reducing compounds than on the formation of brown pigments.
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