The middle lamella is the part of the cell wall that is the outermost layer in between cells. It is rich in pectin, which cements the primary cell walls of adjacent cells together. It provides stability and helps form plasmodesmata between cells. The middle lamella contains calcium and magnesium pectates.
Textural changes during fruit ripening are mainly due to the dissolution of the middle lamella, the reduction of cell-to-cell adhesion, and the weakening of parenchymal cell walls as a result of the action of cell wall-modifying enzymes.