Visible Light-Induced Antibacterial Activity of Pigments Extracted from Dregs of Green and Black Teas

Figure 7

Percentages of inactivation observed in four species of bacteria: (a) Listeria monocytogenes, (b) Staphylococcus aureus, (c) Escherichia coli, and (d) Salmonella typhi, by using the treatment with various sensitizers and under illumination of blue and red LEDs for 30 min. The types of applied sensitizers were as follows: sterile 1% Tween 80 as the medium for pigments dispersion (control), pheophytin a (Pheo a), and pigments recovered from the dregs of green tea (GT) and black tea (BT). The error bars represent standard error of the mean for three repetitions in each treatment. The upper letters indicate the significant differences ( < 0.05) among treatments according to pairwise Fisher’s test.

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(b)

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(d)