JWSS - Journal of Water and Soil Science

The objective of this investigation is to measure pectinesterase activity by a simple method. The assay is done at 25°C. Oranges were obtained at a local supermarket in winter. They were peeled and 5 gr sections of the peeled tissue were homogenized in 10% NaCl and 0.5 M phosphate buffer in a homogenizer. The homogenates were centrifuged at 3500 rpm for 20 min. The supernatants were collected, their pH levels were raised to 7.25 using NaOH and the reaction was monitored at 485 nm in a spectrophotometer. The activity of pectinesterase was expressed as micromoles of methanol released per minute.

The results show that this method is reliable, sensitive, and capable of measuring pectinesterase activity of as low as 0.05 unit. The assay method proposed is a very useful analytical tool for the determination of the activities of pectinesterase.