Pectolytic enzyme activity involved in woolly breakdown of stored peaches

The development of woolly breakdown in peaches stored at 0° was accompanied by increased activity of pectinesterase (PE) and inhibition of polygalacturonase (PG) activity. With intermittent warming of the fruit, which delayed the development of woolly breakdown, PG activity increased to levels measured in normally ripened fruit. It is proposed that the development of woolly breakdown in cold-stored peaches derives from an imbalance of pectolytic activity, whereby low temperatures induce PE to cause the accumulation of de-esterified pectate (soluble in EDTA) and inhibit PG from degrading this substrate.