Influence of calcium on pectin methylesterase behaviour in the presence of medium methylated pectins

► The behaviour of two methylesterases is studied on pectin with or without calcium. ► The presence or not of calcium led to gel or solution conditions. ► With calcium, the processivity of orange PME was decreased. ► Gel formation seems to generate physical constraint for PME diffusion. ► This hinders its diffusion and induces changes in its activity.