Cherries, phenolic compounds

Other plants such as potatoes, cauliflower, cherries, and soybeans and several fungi may also be used as sources of peroxidase enzymes. Soybeans, in particular, may represent a valuable source of peroxidase because the enzyme is found in the seed coat, which is a waste product from soybean-based industries [90]. In this case, it may be possible to use the solid waste from the soybean industry to treat the wastewaters of various chemical industries. In fact, the direct use of raw soybean hulls to accomplish the removal of phenol and 2-chlorophenol has been demonstrated [105]. However, it should be noted that this type of approach would result in an increase in the amount of solid residues that must be disposed following treatment. Peroxidases extracted from tomato and water hyacinth plants were also used to polymerize phenolic substrates [106], Actual plant roots were also used for in vivo experiments of pollutant removal. The peroxidases studied accomplished good removal of the test substrate guaiacol and the plant roots precipitated the phenolic pollutants at the roots surface. It was suggested that plant roots be used as natural immobilized enzyme systems to remove phenolic compounds from aquatic systems and soils. The direct use of plant material as an enzyme source represents a very interesting alternative to the use of purified enzymes due to its potentially lower cost. However, further studies are needed to confirm the feasibility of such a process. 

Blouin, F. A., Narins, Z. M. and Cherry, J.P. (1982). Discoloration of proteins by binding with phenolic compounds. In "Food Protein Deterioration Mechanisms and Functionality", J.P. Cherry, Ed., American Chemical Society Symposium Series, Washington, D.C. 206, 67-91. ... 

This method is also used to measure ex vivo low-density lipoprotein (LDL) oxidation. LDL is isolated fresh from blood samples, oxidation is initiated by Cu(II) or AAPH, and peroxidation of the lipid components is followed at 234 nm for conjugated dienes (Prior and others 2005). In this specific case the procedure can be used to assess the interaction of certain antioxidant compounds, such as vitamin E, carotenoids, and retinyl stearate, exerting a protective effect on LDL (Esterbauer and others 1989). Hence, Viana and others (1996) studied the in vitro antioxidative effects of an extract rich in flavonoids. Similarly, Pearson and others (1999) assessed the ability of compounds in apple juices and extracts from fresh apple to protect LDL. Wang and Goodman (1999) examined the antioxidant properties of 26 common dietary phenolic agents in an ex vivo LDL oxidation model. Salleh and others (2002) screened 12 edible plant extracts rich in polyphenols for their potential to inhibit oxidation of LDL in vitro. Gongalves and others (2004) observed that phenolic extracts from cherry inhibited LDL oxidation in vitro in a dose-dependent manner. Yildirin and others (2007) demonstrated that grapes inhibited oxidation of human LDL at a level comparable to wine. Coinu and others (2007) studied the antioxidant properties of extracts obtained from artichoke leaves and outer bracts measured on human oxidized LDL. Milde and others (2007) showed that many phenolics, as well as carotenoids, enhance resistance to LDL oxidation. 

The lipid system also influences the effectiveness of flavonoids as antioxidants. For example, (+)-catechin was more effective than quercetin in an aqueous-based system (Meyer et al., 1998b). Wang et al. (1999b) found that 6,7-dimethoxy-5,8,4 -trihydroxyflavone was the most active of the polyphenols isolated from tart cherries. These researchers also noted that the pure compound was more effective than a mixture of the isolated phenols at the concentrations originally found in the extract. 

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