Value-added use of mushroom ergothioneine as a colour stabilizer in processed fish meats

BACKGROUND: Ergothioneine (ESH), a potent antioxidant, has been found in certain edible mushrooms. Our previous research showed that ESH extracted from the edible mushroom Flammulina velutipes has a positive effect on the colour stability of beef and tuna meat. The purpose of the present study was to compare the efficacy and applicability of ESH extracts prepared from different mushroom species as a colour stabilizer in fish meats. RESULTS: Levels of ESH higher than 2.8 mg mL(-1) were found in extracts prepared from the fruiting bodies of F. velutipes, Lentinula edodes, Pleurotus cornucopiae and Pleurotus eryngii and the processing waste of F. velutipes. When 1 mL of each of the extracts was added to 1009 of minced bigeye tuna and yellowtail meats, the bright-red colour remained after 5 and 2 days, respectively, of ice storage. The anti-discoloration efficacy of 1 mL of the extracts prepared from 10 g of the fresh waste portion of F. velutipes was similar to that of its fruiting body or 0.5 g kg(-1) of sodium ascorbate when added to 100 g of minced bigeye tuna meat under ice storage. CONCLUSION: The results of this study clearly showed that ESH prepared from different mushroom species stabilized the colour of fish meats, and the extract from the F. velutipes was the most effective. (C) 2010 Society of Chemical Industry