Laccase activity unit

The data in Table 12.11 demonstrate the effectiveness of SO2 in destroying laccase. Three different wines receive 0, 50 and 100 mg of sulfur dioxide per liter. The second column indicates the combination rate, which is particularly elevated in wine 1. This wine also has the lowest residual free SO2 concentrations. The following columns indicate the decrease in laccase activity (expressed in arbitrary units) after sulfiting. In wine 3, the enzyme has not totally disappeared within 15 days of sulfiting at a high concentration (10 /g/hl). 

Superoxide anion scavenging activity of the enzymatically synthesized poly(catechin) was evaluated. Poly(catechin), synthesized by HRP catalyst, greatly scavenged superoxide anion in a concentration-dependent manner, and almost completely scavenged at 200 p.M of a catechin unit concentration. The laccase-catalyzed synthesized poly(catechin) also showed excellent antioxidant property. Catechin showed pro-oxidant property in concentrations lower than 300 jlM. These results demonstrated that the enzymatically synthesized poly(catechin) possessed much higher potential for superoxide anion scavenging, compared with intact catechin. 

The network structure of lignin, which is made of phenol units, coagulates the cell wall in wood tissue, which is composed of cellulose and hemicellulose. Lignin is currently a waste product because of its complicated structure [1-4], It is produced by an oxidative polymerization of coniferyl alcohol, sinapil alcohol, and cumarol alcohol (Figure 1) catalyzed by metalloenzymes such as laccase and peroxidases. Laccase is a protein whose active center contains four coppers per one subunit [5-20],... 

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