Application Method

pH Measurement of Sushi Rice

Application Method

Obtain Optimal Results Using a Specialized Sensor Designed for Measuring the pH of Sushi Rice

pH of sushi rice
pH of sushi rice

The nature of rice samples make it difficult to accurately measure the pH of sushi rice using a conventional sensor. Conventional sensors have a ceramic junction, which allows reduced outflow of a reference electrolyte. Because of insufficient interaction between the sample and the electrolyte, readings take longer than usual. Ceramic junction also poses the challenge of sample particles clogging the frit or ceramic junction, thus decreasing or stopping the interaction between the sample and the reference electrolyte. All of the mentioned factors are responsible for the inconsistency in readings. Therefore, a specialized sensor is required to accurately measure the pH of sushi rice.

To measure the pH of sushi rice with accuracy and precision, METTLER TOLEDO offers the specialized sensor InLab Solids Pro-ISM. The sensor has a spear shaped tip made of toughened glass that allows direct insertion into the rice samples and is resistant to damage. The low maintenance solid XEROLYT®EXTRA polymer reference system offers two benefits: it has a clog-free open junction, which eliminates the risk of protein fouling and the sensor interacts with the sample through diffusing ions. This eliminates the difficulties associated with the immiscibility of aqueous reference electrolyte with the sample. The specialized design and overall sensor technology of the InLab Solids Pro-ISM ensures the direct pH measurement of rice samples, which is critical for ensuring reliability and consistency in the preparation and quality control of sushi rice.

Download our application note to learn more about the advantages of using our sensor.

In the following section, learn more about measuring the pH sushi rice and its importance in maintaining the quality of your product.


Why is measuring the pH of sushi rice important?

For safe consumption of sushi, the pH of the rice must be maintained within the range of 4.1 to 4.6 (at ambient temperature) as per the Food Standards Code. This acidic pH range prevents the growth of pathogenic bacteria and production of toxins.


How is sushi rice acidified?

Various health regulatory bodies have Hazard Analysis Critical Control Point (HACCP) guidelines for the safe handling and pH testing of sushi rice. In order to have consistent flavor in each batch of sushi, the rice is acidified to a fixed pH level. The acidifica¬tion of rice is done using food vinegar (acetic acid). The increased acidity level allows for the storage and serving of sushi in a temperature greater than 5°C.


What happens if sushi rice is not acidified properly?

Inadequately acidified rice in sushi may lead to serious health risks, especially if it is not stored in the controlled temperature mentioned by the regulatory bodies. For this purpose, sushi businesses implement a system for time and temperature monitoring along with pH recordings.

For more information about sample preparation, measurement tips and sensor advantages, download our application note on the pH measurement of sushi rice.