Pectic acid definition

Versteeg (8) speculated on the function of PE in vivo. He noted the high activity of PE in citrus fruit compared to the amount of available pectin. The fruit contain sufficient activity to deesterify the pectin to low methoxy pectin in 10 min at optimum pH. He suggested that the methyl transferase found by Kauss and Hassid (39) to esterify pectic acid to pectin in mung bean shoots and to be located in a lipid-membrane complex (31) functioned as pectinesterase after the lipid membranes were destroyed and the environment changed. However, no definitive experiments to establish the role of PE in fruits were reported. 

Grape polysaccharides resnlt from the breakdown and solnbilization of some of the pectic substances in the skin and flesh cell walls. The terminology describing these componnds may be confusing, as the definition of certain terms (pectins, gums, neutral pectic substances, acid pectic snbstances, etc.) varies from one anthor to another. 

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