CALCIUM-CHLORIDE ADDED TO IRRIGATION WATER OF MUSHROOMS (AGARICUS-BISPORUS) REDUCES POSTHARVEST BROWNING

The influence of 0.3% CaCl2 added to irrigation water on mushroom tyro sinase activity and postharvest browning was examined, Calcium concent ration of mushrooms was significantly increased with the addition CaCl 2 to irrigation water but had no effect on inherent tyrosinase activit y but reduced postharvest browning, The CaCl2 had even more pronounced improvement in shelf life as indicated by reduced browning following a standard bruising treatment, Transmission electron micrographs indic ate that increased levels of calcium in mushrooms irrigated with CaCl2 may have decreased browning by increasing vacuolar membrane integrity ; thereby reducing the opportunity for tyrosinase to react with its su bstrates.