Application Method

pH Measurement of Fruit Juice

Application Method

Confidently Measure the pH of Fruit Juice Using the Right Sensor and Good Measuring Practices

pH of fruit juice
pH of fruit juice

Measuring the pH of fruit juice using a conventional sensor is difficult due to the presence of particulate matter within the sample. The particulate matter may in the long run lead to the clogging of the ceramic junction. This would in turn obstruct the flow of an electrolyte out of the sensor, thus causing insufficient interaction with the sample. As a result, fluctuation in the readings would be observed and would eventually affect the consistency of readings. Continuous usage along with insufficient cleaning would also lead to sensor fouling. Therefore, a sensor practically free of junction blockage issues is must for measuring the pH of fruit juice samples.

METTLER TOLEDO's InLab Max Pro ISM is an apt sensor for measuring the pH of fruit juice samples. The sensor has an immovable glass sleeve junction that helps measure the pH in samples that contain dispersed particulate substances, with shorter response times. The sleeve junction maintains a steady flow of electrolyte even in the dense suspension of juice sample and prevents the ingress of sample into the reference system. The sensor thus eliminates issues related to the clogging of the junction and is an easy to clean sensor.

Download the application note to learn more benefits of using this specialized sensor for measuring the pH of fruit juice.


The following sections highlight additional facts about fruit juice and the importance of monitoring the pH of fruit juice.

What are fruit juices?

Nutrient rich drinks made from the extraction or pressing of the natural liquid contained in fruit and vegetables.

Why is measuring the pH of fruit juice important?

Among the several intrinsic factors that affect the shelf life and spoilage-rate of juice, pH and water activity are the most influential. Variations of pH can influence flavor, consistency, and shelf life. Fruit juices usually have low pH values that range between 2.0 and 4.5 due to the presence of organic acids that vary within the different type of juices. In order to maintain consistency in the quality of juice, monitoring pH is important.

How are fruit juices preserved?

One of the methods for preservation and processing of fruit juices is pasteurization. High-temperature, short-time (HTST) pasteurization is preferred for perishable beverages as it prevents microbial growth and maintains freshness, color and better flavor. pH also plays an important role in managing the parameters of these preservation techniques.

For further details on sensor selection, good measuring practices and measurement procedures download the application note by clicking the button above.