Studies on pectin

IT is now some time since Nanji, Paton and Ling [1925] showed that the constitution of the unit of the pectin molecule might be expressed by a definite chemical formula. Their views seem to have met with fairly general accep- tance, as evinced by a number of later publications by various authors. Little attempt, however, has been made subsequently to examine the conse- quences following the treatment of pectin as a definite chemical entity. A number of researches has been carried out on the condition and function of pectin in the plant tissues, while the metabolic changes undergone by the pectic substances during the ripening and senescence of fruits have received particular attention; but in most cases the physiological aspect has been predominant, to the neglect of the chemistry of the subject. This is un- fortunate, since it is not possible to obtain a complete and true picture of the metabolism of any substance until the chemical changes which result in its formation and which occur in its degradation have been elucidated.