To the neutral solution titrated for equivalent weight containing 0.5g of pectic substance, 25mL of 0.25N NaOH was added, shaken thoroughly and was allowed to stand for 30 minutes at room temperature in a flask with stopper. A 25mL portion of 0.25N HCl (or an amount equivalent to the base added) was added and was titrated with 0.1N NaOH to the same endpoint as the previous one (Titration B).