Water-, oxalate-, acid- and alkali-soluble pectic substances as well as pectolytic enzymes activity
and ethylene evolution were monitored in cape-gooseberry (Physalis peruviana L.) fruits throughout
their development and ripening. The water- and oxalate-soluble pectic substances were found to
increase while those of acid- and alkali-soluble pectic substances decreased during ripening.
Simultaneously with the degradation of high molecular weight pectin, there was a 5–6-fold increase
in polygalacturonase activity but pectin methylesterase activity was not clearly related to fruit
ripening. The increased level of polygalacturonase activity was highly correlated with ethylene
evolution although ethylene evolution occurred prior to polygalacturonase synthesis in fruit tissue.
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