In both maple and birch saps there is significant but low glycoside hydrolase activity. Maple sap preparations were higher in invertase and lower in amylase activity than the corresponding birch preparations; invertase and amylase activity was approximately the same in the two xylem tissues. Sucrose predominates in maple sap and glucose and fructose in birch sap but this difference cannot be ascribed to enzyme activity in either the sapper seor in the xylem tissue of the tree trunks.
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